1. THE
HUMAN
BODY
By: Allee Wheaton

2. TISSUES
 Are a group of cells that perform a single function.
 There are 4 basic types of tissues:
Epithelial, Connective, Nervous, Muscle.
 Epithelial – includes glands and tissues that cover
interior and exterior body surfaces.
 Connective – provides support for the body and
connects its parts.
 Nervous – transmits nerve impulses throughout the
body.
 Muscle – along with bones, enables the body to
move.

3. TISSUES
Epithelial Connective
Nervous Muscle

4. NERVOUS SYSTEM
 Consists of the Brain, Spinal Cord, and Peripheral
nerves.
 Recognizes and coordinates the body’s response to
changes in its internal and external environments.
 Messages carried by the nervous system are
electrical signals called impulses.
Made of a
cell body,
dendrites Nerve cell
and called a
axons neuron.

5. NERVOUS SYSTEM
 Cells that transmit impulses are called neurons.
 Neurons are classified into 3 types based on the
direction in which the impulse travels.
 There are Sensory, Motor, and Interneurons.
 Sensory neurons – carry impulses from organs to
the spinal cord and brain.
 Motor neurons – carry impulses from the brain and
spinal cord to muscles and glands.
 Interneurons – connect sensory and motor
neurons and carry impulses between them.

6. NERVOUS SYSTEM
 Divided into 2 major divisions: the Central Nervous
System (CNS) and the Peripheral Nervous
System (PNS).
 The CNS is the control center of the body. Relays
messages, processes and analyzes information.
Consists of the brain and spinal cord.
 The PNS receives information from the
environment and relays commands from the CNS
to organs and glands. Consists of all the nerves
and associated cells that are not part of the brain
and spinal cord.

7. CNS
 Brain – place to which impulses flow and where they
originate. Contains about 100 billion neurons (many are
interneurons). Has a mass of about 1.4 Kilograms
(about 2.5 pounds). Parts of the brain are cerebrum,
cerebellum, brain stem, thalamus, hypothalamus.
 Spinal Cord –the main communications link between
the brain and the rest of the body. Certain kind of
information, including kinds of reflexes are processed
directly in the spinal cord.
 A reflex is a quick, automatic response to stimulus.
Allows your body to respond to danger immediately,
without thinking.

8. THE BRAIN (THE CEREBRUM)
 The largest and more prominent region of the brain.
 Responsible for the voluntary activities of the body.
 Site of intelligence, learning, and judgment.
 Divided into 2 hemispheres - connected by a bond
called the corpus callosum.
 Divided into 4 lobes
 Each side of cerebrum deals with the opposite side of
body.
 Right hemisphere associated with creativity and artistic
ability.
 Left hemisphere associated with analytical and
mathematical ability.

9. THE BRAIN (THE CEREBELLUM & BRAIN
STEM)
 Cerebellum – second largest region of the brain
 located at the back of the skull.
 Coordinates and balances the actions of the
muscles so the body can move gracefully and
efficiently.
 Brain Stem – connects the brain and spinal cord
 located just below the cerebellum
 Includes 2 regions – the pons and medulla
oblongata.
 Body’s most important functions – blood pressure,
heart rate, breathing, and swallowing controlled by
the brain stem.

10. THE BRAIN (THALAMUS & HYPOTHALAMUS)
 Found between the brain stem and cerebrum.
 Thalamus – receives messages from all sensory
receptors and sends it to the proper part of the
cerebrum.
 Hypothalamus – below the thalamus. Control
center of hunger, thirst, fatigue, anger, and body
temperature. Controls coordination of the nervous
and endocrine systems.

11. PNS
 Can be divided into the sensory and motor divisions.
 Nerves are axons bundled together with blood vessels
and connective tissue.
 Sensory – transmits impulses from sense organs to the
CNS.
 Motor – transmits impulses from the CNS to muscles
and glands. Divided into Somatic and Autonomic
nervous systems.
 Somatic –regulates activities that are under conscious
control. Movement of the skeletal muscles.
 Autonomic – regulates activities the are involuntary.
Beating of the heart.

12. SENSES
 The body contains millions of neurons that react to
stimuli from the environment, including light, sound,
motion, chemicals, pressure, and changes in
temperature. These neurons are known as Sensory
Receptors.
 5 categories of sensory receptors: pain receptors,
thermoreceptors, mechanoreceptors,
chemoreceptors, and photoreceptors.

13. SENSES
 Pain Receptors – located throughout body except
brain. Indicate danger, injury, or disease.
 Thermoreceptors – located in skin, body core, and
hypothalamus. Detect temperature changes.
 Mechanoreceptors – located in skin, skeletal
muscles, sound and motion. Sensitive to
touch, pressure, stretching of muscles, sound, and
motion.
 Chemoreceptors – located in nose and taste buds.
Sensitive to chemicals in external environment.
 Photoreceptors – located in eyes. Sensitive to
light.

14. DISORDERS OF THE NERVOUS SYSTEM
 Multiple sclerosis (MS) – It is a chronic disease
affecting more women than men often leading to
progressive neurological deterioration and ataxic
paraplegia. Lesions occur in all parts of the CNS white
matter appearing gray and translucent. Some of the
more prominent structures affected are the medial
longitudinal fasciculus and the optic tract and
chiasm. Damage to the neurons in these structures can
lead to optic neuritis (with complete loss of vision in one
eye), diplopia (double vision) and problems coordinating
eye and head movements. Onset of the disease is
usually between the ages of 20 and 40 years of age.

15. DISORDERS OF THE NERVOUS SYSTEM
 Epilepsy is a brain disorder in which a person has
repeated seizures (convulsions) over time. Seizures
are episodes of disturbed brain activity that cause
changes in attention or behavior. Occurs when
permanent changes in brain tissue cause the brain
to be too excitable or jumpy. The brain sends out
abnormal signals. Epilepsy seizures usually begin
between ages 5 and 20, but they can happen at
any age. There is no cure, but it is treatable.

16. SKELETAL SYSTEM
 Consists of Bones, Cartilage, Ligaments, and
Tendons.
 Supports the body, protects internal organs, allows
movement, stores mineral reserves, and provides a
site for blood cell formation.

17. SKELETAL SYSTEM
 There are 2 types of
skeletons. The axial and
appendicular skeletons.
 Axial Skeleton –
supports the central axis
of the body. Consists of
the skull, sternum, ribs,
and spine.
 Appendicular Skeleton
– Consists of the bones
of the arms, legs, pelvis,
and shoulder.

18. BONES
 They support and shape the body. Protect internal
organs.
 Provide a system of levers on which muscles act to
produce movement.
 Contain reserves of minerals, mainly calcium salts.
 Bones are a site of blood cell formation.
 206 bones in the human body.
 Are a solid network of living cells and protein fibers
that are surrounded by deposits of calcium salts.

19. STRUCTURE OF BONES
 Surrounded by a tough layer of connective tissue
called the periosteum.
 Beneath the periosteum is a thick layer of compact
bone.
 Compact bone is dense, but far from solid. Running
through compact bone is a network of tubes called
Haversian canals that contain blood vessels and
nerves.
 Inside the outer layer of compact bone is a less
dense tissue known as spongy bone. Found in the
end of lone bones and middle of short.

20. STRUCTURE OF BONES
 Within bones are cavities that contain soft tissue
known as bone marrow.
 There are 2 types of bone marrow: Yellow and Red.
 Yellow marrow is made up of primarily fat cells.
 Red marrow produces red blood cells, some kinds
of white blood cells, and cell fragments known as
platelets.
 Cartilage is made of tough collagen and flexible
elastin.

21. STRUCTURE OF BONES

22. JOINTS
 Where one bone attaches to another. 3 types of
joints: Immovable, Slightly movable, and freely
movable.
 Immovable – no movement
 Slightly movable – small amount of restricted
movement.
 Freely Movable – movement in one or more
directions. 4 types: Ball-and-Socket Joint – widest
range of movement on any joint. Hinge Joint – back
and forth motion. Pivot Joint – one bone to rotate
around another. Saddle Joint – one bone to slide in
2 directions.

23. SKELETAL SYSTEM DISORDERS
 Arthritis – inflammation of the joint itself. Lesser
condition called Bursitis which is inflammation of
bursa(small sac of synovial fluid).
 Osteoporosis – weakening of the bone that can
cause serious fractures.

24. MUSCULAR SYSTEM
 Movement is the function of muscular system.
 Includes large muscles and thousands of tiny
muscles that help to regulate blood pressure, move
food through the digestive system, and power every
movement of the body.
 3 types of muscle tissue: skeletal, smooth, and
cardiac.
Skeletal Muscle Smooth Muscle Cardiac Muscle

25. MUSCULAR SYSTEM
 Skeletal Muscle – Attached to bone. Cells are
large from 1mm – 30cm. Consist of muscle fibers,
connective tissues, blood vessels, and nerves.
Consciously controlled by the CNS.
 Smooth Muscle – Not under voluntary control.
Found in hollow structures such as the stomach,
blood vessels, and intestines. Move food through
the digestive tract, and control the way blood flows.
 Cardiac Muscle – found in just the heart. Shares
features with skeletal and smooth muscle.
Involuntary muscle.

26. MUSCULAR SYSTEM
 A muscle contracts when the thin filaments in the
muscle fiber slide over the thick filaments.
 Skeletal muscles are only useful if they contract in a
controlled fashion.
 Skeletal muscles are joined to bones by tough
connective tissue called tendons. Tendons pull on
the bones and make them work like levers.
 Regular exercise is important in maintaining
muscular strength and flexibility.

27. DISORDERS OF THE MUSCULAR SYSTEM
 Muscular Dystrophy, or MD, is an inherited muscle disease
that causes muscle fibers to become incredibly susceptible to
harm. Muscles grow progressively weaker, and muscle fiber is
replaced with fat and other tissue. Symptoms include lack of
coordination, muscle weakness, and a progressive loss of
mobility. There is no cure for the disease, but some therapies
and medications can help slow its progression.
 Cerebral palsy is a disorder that impairs a person's motor
function, posture, and balance. It occurs when there is
damage to the area of the brain responsible for muscle
tone, or the amount of resistance in a muscle. A person with
cerebral palsy will often have difficulty performing physical
tasks, though symptoms vary with the severity of the particular
case.
 Atrophy refers to a state where muscle tissue wastes
away, each muscle fiber shrinking in size. This can be caused
by muscle disuse or when nerve impulses become ineffective.

28. INTEGUMENTARY SYSTEM
 Consists of the skin, hair, nails, and a variety of
glands.
 Serves as a barrier against infection and
injury, helps to regulate body temperature, removes
waste products from the body, and provides
protection against UV rays from the sun.
 Largest component of the integumentary system is
the skin.

29. INTEGUMENTARY SYSTEM

30. THE SKIN
 Contains several types of sensory receptors.
 Has many functions, but the most important
function is protection.
 Serves as a gateway through which sensations
such as pressure, heat, cold, and pain are
transmitted to the nervous system.
 Made up of 2 main layers – the epidermis and the
dermis.
 Beneath the dermis is a sub layer of fat called the
hypodermis and loose connective tissue the help
insulate the body.

31. EPIDERMIS
 Outer layer of the skin. Has 2 layers.
 The outer layer comes in contact with the
environment and is made of dead cells.
 The inner layer is made of living cells and
undergoes rapid cell division. The cells begin to
produce keratin, a tough, fibrous protein.
 Contains melanocytes. Which are cells that
produce melanin, a dark brown pigment that helps
to protect the skin from damage by absorbing UV
rays.
 Skin color is made by the number of melanin that is
produced and where they are distributed.

32. DERMIS
 The inner layer of the skin. Lies beneath the 2
layers of the epidermis.
 Contains collagen fibers, blood vessels, nerve
endings, glands, sensory receptors, smooth
muscles, and hair follicles.
 Contains 2 major types of glands: sweat glands and
sebaceous(oil).
 Sebaceous glands produce an oily secretion called
sebum. Sebum helps keep the keratin-rich
epidermis flexible and waterproof.

33. HAIR
 Covers almost every exposed surface of the body.
 Hair on the head protects the scalp from UV light
and provides insulation from the cold.
 Hair in nostrils, external ear canals, and eyelashes
prevent dirt and other particles from getting into the
body.
 Hair follicles are at the base of the hair and are
tubelike pockets of epidermal cells that extend into
the dermis.
 All of the hair except the follicle is dead and filled
with keratin.

34. NAILS
 Grow from an area of rapid cell division known as
the nail root.
 During cell division, the nail root fills with keratin
and produces a tough, platelike nail that protects
the tips of the fingers and toes.
 Grow at an average rate of 3mm per month.
 Fingernails grow about 4 times as fast as the
toenails.

35. DISORDERS OF THE INTEGUMENTARY SYSTEM
 Skin Cancer – an abnormal growth of cells in the skin.
Caused by excessive exposure to sunlight. The three
most common malignant skin cancers are basal cell
cancer, squamous cell cancer and melanoma.
Treatment is dependent on type of cancer, location of
the cancer, age of the patient, and whether the cancer is
primary or a recurrence.
 Acne vulgaris (or cystic acne) is a common human
skin disease, characterized by areas of skin with
Seborrhea (scaly red skin), Comedones (blackheads
and whiteheads), Papules (pinheads), Pustules
(pimples), Nodules (large papules) and possibly
scarring. Acne affects mostly skin with the densest
population of sebaceous follicles; these areas include
the face, the upper part of the chest, and the back.
Severe acne is inflammatory, but acne can also manifest
in noninflammatory forms.

36. CIRCULATORY SYSTEM
 Humans have closed circulatory system – means
that blood is within a system of vessels.
 Consists of the heart, a series of blood vessels, and
blood.

37. THE HEART
 Composed almost entirely of muscle.
 Inside a protective sac called the pericardium.
 In the walls of the heart are 2 thin layers of epithelial and
connective tissue that surround a thick layer of muscle
called the myocardium.
 The myocardium pumps blood through the circulatory
system.
 The heart muscle contracts about 72 times a minute,
pumping about 70mL of blood with each contraction.
 In 1 year the heart pumps more than enough blood to fill
an Olympic-sized swimming pool.
 An Olympic-sized swimming pool is about 2,000,000L.
 The heart pumps about 2,649,024L of blood in 1 year.

38. THE HEART
 Dividing the right and left sides of the heart is the
septum.
 The septum prevents oxygen-poor and oxygen-rich
blood from mixing.
 There are 2 chambers on each side of the septum.
 The upper chamber, which receives blood, is the
atrium (plural: atria)
 The lower chamber, which pumps blood out of the
heart is the ventricle.
 Has 4 chambers: 2 atria and 2 ventricles.

39. THE HEART

40. CIRCULATION THROUGH HEART
 Blood enters through the right and left atria and goes to
the ventricles.
 When the heart contracts blood moves in and then out
of the ventricles to the body or lungs.
 Flaps of tissue between the atria and ventricles are
called valves. When blood moves from the atria it holds
the valves open. When the heart contracts the valves
close to prevent blood from flowing back into the atria.
There are valves at the exits of the ventricles to keep
blood from flowing back into the heart. The valves keep
the blood moving in 1 direction.

41. CIRCULATION THROUGH BODY
 The heart functions as 2 separate pumps.
 3 types of circulation.
 Coronary – pumps blood only to the vessels on the
muscle of the heart.
 Pulmonary – oxygen-poor blood flows to the right
side of the heart and then pumps the blood to the
lungs to get oxygen.
 Systemic – the oxygen-rich blood the flows to the
left side of the heart and is pumped to the rest of
the body.

42. 
HEARTBEAT
Each contraction begins in a small group of cardiac
muscle cells known as the sinoatrial node (SA node),
located in the right atrium. These cells are also known
as the pacemaker.
 The impulse spreads from the SA node to the network
of fibers in the atria. It is picked up by a bundle of fibers
called the atrioventricular node (AV node) and carried
to a network of fibers in the ventricles.
 When the network in the atria contracts, blood in the
atria flows into the ventricles. When the muscles in the
ventricles contract, blood flows out of the heart. This 2-
step pattern of contraction makes the heart more
efficient.

43. BLOOD VESSELS
 When blood leaves the left ventricle, it passes through
the largest blood vessel in the body, the aorta. The
aorta is the first of a series of blood vessels that carry
blood on a round trip through the body and back to the
heart.
 Blood flows through 3 types of blood vessels:
arteries, capillaries, and veins.
 Arteries – large vessels that carry blood to the tissues
of the body. Are the superhighways of the circulatory
system. Except for pulmonary arteries, all arteries
carry oxygen-rich blood. Have thick walls that help
them withstand the powerful pressure produced when
the heart contracts.

44. BLOOD VESSELS
 Capillaries – smallest of the blood vessels. Are the
side streets and alleys of the circulatory system. The
walls of capillaries are only 1 cell thick, and most are so
narrow cells have to travel single file through them. The
real work of the circulatory system – bringing nutrients
and oxygen to the tissues and absorbing CO2 and other
waste products from them – is done in the capillaries.
 Veins – responsible for returning oxygen-poor blood
back to the heart. The walls contain connective tissue
and smooth muscle. Large veins have valves to keep
blood flowing to the heart. Many veins are located near
and between skeletal muscle.

45. BLOOD PRESSURE
 When the heart contracts it creates a wave of fluid
pressure in the arteries. The force of the blood on the
arteries’ walls is known as blood pressure.
 Measured with a sphygmomanometer. A cuff is wrapped
around the upper arm and filled with air until an artery is
blocked. As the pressure is released, the pulse is
listened to with a stethoscope and 2 numbers are
recorded off a pressure gauge.
 The 1st number is the systolic pressure – the force felt
in the arteries when the ventricles contract. The 2nd
number is diastolic pressure – force of blood in the
arteries when the ventricles relax.
 A typical blood pressure in a healthy person is 120/80.

46. DISORDERS OF THE CIRCULATORY
SYSTEM
 Atherosclerosis – condition in which plaque builds up
on the interior walls of the arteries. Particularly
dangerous in the coronary arteries – if one gets blocked
the heart can’t receive enough oxygen so the person has
a heart attack. People can also experience a stroke –
where a bod clot breaks free and gets stuck in one of the
vessels leading to the brain.
 High Blood Pressure – or hypertension forces the heart
to work harder, which may weaken and damage the
heart muscle and blood vessels. People are more likely
to develop coronary heart disease and other diseases of
the circulatory system. At risk for heart attack and stroke.

47. BLOOD SYSTEM
 The human body contains 4-6 liters of blood. 8% of the
total mass of the body.
 About 45% of blood volume contains cells which are
suspended in the other 55% - a straw-colored fluid
called plasma.
 Plasma – is about 90% water and 10% dissolved
gases, salts, nutrients, enzymes, hormones, waste
products, and plasma proteins.
 2 types of cells: red and white blood cells.
 Red Blood Cells – transport oxygen. Get color from
hemoglobin – iron containing protein that binds oxygen
to the cells. Most numerous blood cell. Circulate for
120 days before destroyed by liver and spleen.

48. BLOOD SYSTEM
 White Blood Cells – or leukocytes do not contain
hemoglobin. Red blood cells out number them about
1000 to 1. Known as the “army” of the circulatory
system. They guard against infection, fight
parasites, and attack bacteria. A special class of white
blood cells, known as lymphocytes produce
antibodies that are proteins that help destroy
pathogens.
 Platelets – blood clotting is made possible by plasma
proteins and cell fragments called platelets. Each
fragment of cytoplasm made from a cell in the bone
marrow is enclosed in a piece of cell membrane and
released into the blood stream as a platelet.

49. BLOOD SYSTEM
Red and White Blood Cells

50. DISORDER OF THE BLOOD SYSTEM
 Hemophilia – is a genetic disorder that results from
a defective protein in the clotting pathway. People
with hemophilia cannot produce blood clots that are
firm enough to stop even minor bleeding. They
must take great care to avoid injury.
Fortunately, hemophilia can be treated by injecting
extracts containing the missing clotting factor.

51. LYMPHATIC SYSTEM
 More than 3 liters of fluid leak from the circulatory system
everyday.
 A network of vessels, nodes, and organs called the
lymphatic system collects the fluid that is lost by the
blood and returns it back to the circulatory system.
 This fluid is known as lymph.
 Ducts collect the lymph and return it to the circulatory
system through 2 openings in the superior vena cava.
 Lymph nodes act as filters, trapping bacteria and other
microorganisms that cause disease.
 Lymph vessels absorb fats and fat-soluble vitamins from
the digestive tract and carry them to the blood.
 The spleen helps to cleanse the blood and remove
damaged blood cells from the circulatory system.

52. LYMPHATIC SYSTEM

53. DISORDERS OF THE LYMPHATIC
SYSTEM
 Lymphedema - The lymphatic system clears away
infection and keeps your body fluids in balance. If
it's not working properly, fluid builds in your tissues
and causes swelling.
 Lymphoma is a cancer of the lymphocytes.
Typically, lymphomas present as a solid tumor of
lymphoid cells. Treatment might involve
chemotherapy and in some cases radiotherapy
and/or bone marrow transplantation, and can be
curable depending on the histology, type, and stage
of the disease

54. RESPIRATORY SYSTEM
 Function is to bring about the exchange of oxygen and
CO2 between the blood, the air, and tissues.
 Consists of the nose, pharynx, larynx, trachea, bronchi,
and lungs.
 Air moves from the nose to a tube at the back of the
mouth called the pharynx. The pharynx, or throat. It
serves as a passageway for both air and food.
 Air moves from the pharynx to the trachea, or windpipe.
A flap of tissue called the epiglottis covers the entrance
of it when you swallow.
 Air that enters the respiratory system must be warmed,
moistened, and filtered to keep the lungs healthy.

55. RESPIRATORY SYSTEM
 Come cells that line the respiratory system create a thin
layer of mucus. Mucus moistens the air and traps
particles of dust or smoke that are inhaled.
 The cilia sweep the trapped particles and mucus away
from the lungs toward the pharynx.
 The mucus and trapped particles are swallowed or spit
out.
 The Larynx is at the top of the trachea. Contains 2
highly elastic folds of tissue known as the vocal cords.
When muscles pull on the vocal cords they vibrate and
produce sounds. The ability to speak, shout, and sings
comes from these tissues.

56. RESPIRATORY SYSTEM
 From the larynx, air passes through the trachea into 2
large passageways in the chest called bronchi
(singular: bronchus). Each bronchus leads into one of
the lungs. Large bronchus divides into smaller bronchi,
which divide into smaller passages called bronchioles.
 The bronchi and bronchioles are surrounded by smooth
muscle that helps support them and enables the
automatic nervous system to regulate the size of the
passageways.
 The bronchioles continue to divide until they reach a
series a dead cells – millions of tiny air sacs called
alveoli (singular: alveolus).

57. RESPIRATORY SYSTEM
 Alveoli are grouped in little clusters. A delicate network
of thin-walled capillaries surround each alveolus.
 There are about 150 million alveoli in each healthy
lung.
 The air that is inhaled is about 21% oxygen and 0.4%
CO2
 Exhaled air has less than 15% oxygen and 4% CO2.
 Since oxygen dissolves easily there is no need for
hemoglobin, but hemoglobin increases the oxygen-
carrying capacity of the blood more than 60 times.
Without hemoglobin your body would need about 300
liters of blood instead of 4-6 liters.

58. RESPIRATORY SYSTEM
 Breathing is the movement of air in and out of the lungs.
 The lungs are sealed in 2 sacs, called the pleural
membranes.
 At the bottom of the chest cavity is a large, flat muscle
known as the diaphragm. When you breath in the
diaphragm contracts and the rib cage rises crating more
volume in the chest cavity.
 The upper part of the respiratory system is usually able to
filter out dust and other particles that could damage the
lungs. Smoking tobacco damages and eventually
destroys this protective system.

59. RESPIRATORY SYSTEM

60. DISEASES OF THE RESPIRATORY SYSTEM
 Emphysema – is the loss of elasticity in the tissues of
the lungs. This condition makes breathing very difficult.
People who have it cannot get enough oxygen to the
body tissues or rid the body of excess CO2.
 Chronic Bronchitis – the bronchi become swollen and
clogged with mucus. Even smoking a moderate
number of cigarettes on a regular basis can cause
chronic bronchitis. Affected people often find simple
activities, such as climbing stairs, difficult.

61. DIGESTIVE SYSTEM
 Calorie – is equal to 1000 calories(the amount of
heat need to raise the temperature of 1g of water
by 1 degree Celsius is 1 calorie.) Average amount
of Calories needed per day for a female is 2200, for
a male is 2800.
 The nutrients that the body needs are
water, carbohydrates, fats, proteins, vitamins, and
minerals.
 Every cell in the body needs water because many
of the body’s processes, including chemical
reactions take place in water.

62. DIGESTIVE SYSTEM
 Carbohydrates – are simple and complex. The main
source of energy for the body.
 Fats – or lipids, body needs essential fatty acids to produce
cell membranes, myelin sheaths, and certain hormones.
Help body absorb vitamins.
 Proteins – supply raw materials for growth and repair of
structures such as skin and muscle. Insulin and hemoglobin
are just 2 examples of proteins.
 Vitamins – are organic molecules that help regulate body
processes, often work with enzymes. Examples are vitamins
A, D, E, K, C, B1, B12, B6.
 Minerals – inorganic nutrients that the body needs, usually
in small amounts. Examples are calcium, iron, and
magnesium.

63. DIGESTIVE SYSTEM
 Includes the mouth, pharynx, esophagus, stomach, small
intestine, and large intestine.
 Several major accessories including the salivary glands,
pancreas, and liver add secretions to the system.
 Function of the system is to help convert foods into simpler
molecules that can be absorbed and used by the cells of the
body.
 Mouth – contain the teeth and saliva. Teeth do much of the
work of mechanical digestion by cutting, tearing, and
crushing food into small fragments. Saliva helps to moisten
the food and make it easier to chew. Contains an enzyme
called amylase that breaks down the chemical bonds in
starches and releases sugars.

64. DIGESTIVE SYSTEM
 Esophagus – during swallowing, the combined
actions of the tongue and throat muscles push the
chewed food, called the bolus, down the throat.
When you swallow, a flap of connective tissue
called the epiglottis closes the opening of the
trachea. This prevents food from blocking the
airway.
 From the throat, the food goes down the
esophagus, or food tube, into the stomach. Muscle
contractions known as peristalsis, squeeze the
food through to the stomach.

65. DIGESTIVE SYSTEM
 A thick ring of muscle called the cardiac
sphincter, closes the esophagus after food has
passed into the stomach and prevents the contents
of the stomach from coming back up.
 Heartburn – is a painful, burning sensation that
feels as if it is coming from the center of the
chest, just above the stomach. Heartburn is the
backflow of stomach acid. It is caused by
overeating or drinking to much caffeinated drinks.

66. DIGESTIVE SYSTEM
 Stomach – food empties from the esophagus into the
large muscular sac called the stomach. Continues the
mechanical and chemical digestions. Alternating
contractions of the stomach’s 3 smooth muscle layers
thoroughly churn and mix the food.
 Chemical Digestion – the lining of the stomach
contains millions of microscopic gastric glands that
release a number of substances into the stomach.
Some glands produce mucus that protect the stomach
lining. Others produce hydrochloric acid, which makes
the stomach contents very acidic. The acid activates
pepsin, an enzyme that begins the digestion process
along with hydrochloric acid.

67. DIGESTIVE SYSTEM
 Mechanical Digestion – as digestion proceeds, stomach
muscles contract to churn and mix stomach fluids and foods,
gradually producing a mixture known as chyme. After an
hour or two, the pyloric valve, which is located between the
stomach and small intestine, opens and chyme begins to
flow into the small intestine.
 Small Intestine – as chyme is pushed through the pyloric
valve, it enters the duodenum. The duodenum is the first of 3
parts of the small intestine, and it is where almost all of the
digestive enzymes enter the intestine. Most of the chemical
digestion and absorption of the food occurs in the small
intestine. As chyme enters the duodenum, it mixes with
enzymes and digestive fluids from the pancreas, liver, and
the lining of the duodenum.

68. DIGESTIVE SYSTEM
 Pancreas – located just behind the stomach. Is a
gland that serves 3 important functions. One is to
produce hormones that regulate blood sugar. Within
the digestive system, it plays 2 key roles. It produces
enzymes that break down carbohydrates, proteins,
fats, and nucleic acids. Also produces sodium
bicarbonate that neutralizes stomach acids, so the
enzymes can work.
 Liver – assists the pancreas. A large organ located just
above and to the right of the stomach. Produces bile, a
fluid loaded with lipids and salts. Bile dissolves and
disperses droplets of fat found in fatty foods. Bile is
stored in a small pouchlike organ called the
gallbladder.

69. DIGESTIVE SYSTEM
 The folded surfaces of the small intestine are covered
with fingerlike projections called villi. These folds and
projections provide enormous surface area for the
absorption of nutrient molecules.
 When chyme leaves the small intestine it enters the
large intestine, or colon. The primary function of the
large intestine is to remove water from the
undigested material that is left.

70. DIGESTIVE SYSTEM

71. DIGESTIVE SYSTEM DISORDERS
 Peptic Ulcer - when powerful acids of the stomach
sometimes damage it’s own lining, producing a hole
in the stomach wall. Caused by the bacteria
Helicobacter pylori. They can be cured by powerful
antibiotics.
 Diarrhea &Constipation – diarrhea is when not
enough water is absorbed from the waste material.
Constipation is when too much water is absorbed
from the waste material.

72. EXCRETORY SYSTEM
 The kidneys play an important role in maintaining
homeostasis. They remove waste products from the
blood, maintain blood pH, and regulate the water
content of the blood and, therefore, blood volume.
 Kidneys – are located on either side of the spinal
column near the lower back. A tube, called the ureter,
leaves each kidney, carrying urine to the urinary
bladder. The urinary bladder is a saclike organ where
urine is stored before being excreted. As waste-laden
blood enters the kidney through the renal artery, the
kidney removes urea, excess water, and other waste
products and passes them to the ureter.

73. EXCRETORY SYSTEM
 Kidneys – the functional units of the kidney are called
nephrons. Each nephron is a small, independent
processing unit. As blood enters a nephron through the
arteriole, impurities are filtered out and emptied into the
collecting duct. The purified blood exits the nephron
through the venule. The mechanism of blood purification
involves 2 distinct processes: Filtration and reabsorption.
 Filtration – filtration of blood mainly takes place in the
glomerulus. The glomerulus is a small network of
capillaries encased in the upper end of the nephron by a
hollow, cup-shaped structure called the Bowman’s
capsule. The materials that are filtered from the blood are
called the filtrate. The filtrate contains water, urea,
glucose, salts, amino acids, and some vitamins.

74. EXCRETORY SYSTEM
 Reabsorption – not all of the filtrate is excreted. Most
of the material removed from the blood at the bowman’s
capsule makes its way back into the blood. Amino
acids, fats, and glucose are reabsorbed by the
capillaries. Almost 99% of the water is reabsorbed back
into the blood.
 Urine Formation – the material that remains, called
urine, is emptied into a collecting duct. Urine which
contains urea, salts, and water, among other
substances, is primarily concentrated in the loop of
Henle. The loop of Henle is a section of the nephron
tubule in which water is conserved and the volume of
urine minimized.

75. EXCRETORY SYSTEM

76. EXCRETORY SYSTEM DISORDERS
 Kidney Stones – sometimes substances such as
calcium, magnesium, or uric acid salts in the urine
crystallize and form kidney stones. When kidney stones
block the ureter, they cause great pain. They are often
treated with ultrasound waves. The sound waves pulverize
the stones into smaller fragments, which are eliminated
with the urine.

77. EXCRETORY SYSTEM
 An inflammation of the nephrons of the kidneys can result in
Nephritis, also sometimes referred to as Bright’s disease.
There are many irritants that can cause
inflammation, including exposure to turpentine, bichloride of
mercy, or even exposure to a cold or following very mild
throat infections. Nephritis may also arise after exposure to
toxins from scarlet fever, tonsillitis, alcohol or measles.
Avoiding fatigue or chilling, or anything that lowers the body’s
resistence against infections and colds can decrease the
probability of developing Nephritis. There are two kinds of
nephritis: acute and chronic. In acute nephritis, the symptoms
vary, but generally they involve dropsy in the ankles and
eyelids, presence of albumen in the urine, suppression of
urine, and sometimes convulsions. In most cases, there is no
damage to the kidneys or other body parts, but in very severe
cases death can result. When the kidneys suffer permanent
damage, nephritis is chronic.

78. ENDOCRINE SYSTEM
 Made up of glands that release their products into the
bloodstream. These products deliver messages
throughout the body.
 The chemicals that “broadcast” messages from the
system are called hormones. Hormones are chemicals
released in one part of the body that travel through the
bloodstream and affect the activities of cells in other
parts of the body. They do this by binding to specific
chemical receptors. The cells that contain the chemical
receptors are called target cells.
 A gland is an organ that produces and releases a
substance or secretion.

79. ENDOCRINE SYSTEM
 Unlike exocrine glands, endocrine glands release their
secretions (hormones) directly into the bloodstream.
 Hormones are classified into 2 general groups: steroid
hormones and nonsteroid hormones. Steroid hormones
are produced from a lipid called cholesterol. Nonsteroid
hormones include proteins, small peptides, and modified
amino acids.
 Except for red blood cells, all cells have been shown to
produce small amounts of hormone like substances
called prostaglandins. They are modified fatty acids
that are produces by a wide range of cells.
 The Endocrine system is regulated by feedback
mechanisms that function to maintain homeostasis.

80. ENDOCRINE SYSTEM
 Pituitary Gland – a bean sized structure that dangles
on a slender stalk of tissue at the base of the skull.
Secretes 9 hormones that directly regulate main body
functions and controls the actions of several other
endocrine glands.
 Hypothalamus – above and attached to the back of the
pituitary gland. Controls the secretions of the pituitary
gland.
 Thyroid Gland – has the major role in regulating the
body’s metabolism.
 Parathyroid Gland – act to maintain homeostasis of
calcium levels in the blood.

81. ENDOCRINE SYSTEM
 Adrenal Glands – release hormones that help the body
prepare for and deal with stress. Consists of 2 parts.
Adrenal Cortex – 80% of the gland. Produces more
than 2 dozen steroid hormones called corticosteroids.
Adrenal Medulla – the release of its hormones is
regulated by the sympathetic nervous system.
 Pancreas – the hormone producing portion consists of
clusters of cells that resemble islands. Clusters are
called islets of Langerhans. Each islet includes beta
cells that produce insulin, and alpha cells that produce
glucagon. Insulin and glucagon help to keep the level of
glucose in the blood stable.

82. ENDOCRINE SYSTEM
 Reproductive Glands - the gonads are the reproductive
glands. The gonads serve 2 important functions: the
production of gametes and the secretion of sex hormones.
The female gonads – the ovaries – produce eggs and
produce the sex hormones estrogen and progesterone. The
male gonads – testes – produce sperm and the sex
hormone testosterone.

83. ENDOCRINE SYSTEM

84. ENDOCRINE SYSTEM DISORDERS
 Diabetes mellitus – when the pancreas fails to produce or
properly use insulin. The amount of glucose in the blood may
rise so high that the kidneys actually excrete glucose in the
urine. Very high blood glucose levels can damage almost
every cell in the body, including the coronary artery.
 Addison's disease - occurs if the adrenal glands don't make
enough of these hormones. A problem with your immune
system usually causes Addison's disease. The immune
system mistakenly attacks your own tissues, damaging your
adrenal glands. Symptoms include: Weight loss, Muscle
weakness, Fatigue that gets worse over time, Low blood
pressure, Patchy or dark skin. Lab tests can confirm that you
have Addison's disease. If you don't treat it, it can be fatal.
You will need to take hormone pills for the rest of your life. If
you have Addison's disease, you should carry an emergency
ID. It should say that you have the disease, list your
medicines and say how much you need in an emergency

85. IMMUNE SYSTEM
 The function of the immune system is to fight infection
through the production of cells that inactivate foreign
substances or cells. This process is called immunity.
 There are 2 categories of defense mechanisms:
nonspecific and specific defenses.
 Nonspecific Defenses – do not discriminate between
one threat and another. This includes physical and
chemical barriers. First line of defense is to keep
pathogens out of the body. Carried out by skin (most
important), mucus, sweat, and tears. Second line of
defense – when pathogens enter the body and release
toxins the inflammatory response is activated. The
inflammatory response is a reaction to tissue damage
caused by injury or infection.

86. IMMUNE SYSTEM
 Interferons – virus-infected cells produce a group of
proteins that help other cells resist viral infection. They
interfere and block the growth of the virus.
 Specific Defenses – when the pathogen gets passed
the nonspecific defenses. These defenses are called
the immune response. A substance that triggers this
response is known as an antigen. 2 types of cells that
recognize specific antigens are B cells (B lymphocytes)
and T cells (T lymphocytes). B cells provide immunity
against antigens and pathogens in the body fluids. This
is called humoral immunity. T cells provide a defense
against abnormal cells and pathogens inside living
cells. This is called cell-mediated immunity.

87. IMMUNE SYSTEM
 Humoral Immunity - when a pathogen enters the
body, its antigens are recognized by a small fraction of
the body’s B cells. These B cells grow and divide
rapidly, producing large numbers of plasma cells and
memory B cells. Plasma cells release antibodies.
Antibodies are proteins that recognize and bind to
antigens. Are carried in the bloodstream to attack the
pathogen that is causing the infection.
 Cell-Mediated Immunity – the body’s primary defense
against its own cells when they have become
cancerous or infected by viruses. Important in fighting
infection caused by fungi and protists.

88. IMMUNE SYSTEM
 Active Immunity – type of immunity produced by the
body’s reaction to a vaccine. Vaccination – the
injection of a weakened form of a pathogen to produce
immunity. They stimulate the immune system to create
millions of plasma cells ready to produce specific types
of antibodies. Appears after exposure to an antigen, as
a result of the immune response. May result from
natural exposure (fighting an infection) or deliberate
exposure (through a vaccine). Makes its own response
antibodies to fight an antigen.

89. IMMUNE SYSTEM
 Passive Immunity – when antibodies are produced by
other animals and is injected into the bloodstream, the
antibodies produce a passive immunity against a
pathogen. Lasts for only a short time because the body
destroys foreign antibodies. Can develop naturally or
deliberately. One kind of natural immunity is when a
mother passes antibodies through the placenta or through
breast-feeding. Vaccines for leaving to go to another
country is an example of passive immunization

90. IMMUNE SYSTEM DISORDERS
 Allergies – the most common overreactions of the
immune system. Common allergies include: pollen, dust,
mold, and bee stings. Antigens that cause allergic
reactions are called allergens. When allergy-causing
antigens enter the body they attach to mast cells. Mast
cells are specialized immune system cells that initiate
the inflammatory response. The activated mast cells
release chemicals known as histamines which increase
blood flow to the surrounding area. They increase mucus
production in the respiratory system. The mucus brings
on sneezing, watery eyes, runny nose, and other
irritations. You have to take anti-histamines which are
drugs that are used to counteract the effects of
histamines.

91. IMMUNE SYSTEM DISORDERS
 Asthma - Some allergic reactions can create a dangerous
condition called asthma. It is a chronic respiratory disease
in which the air passages become narrower than normal.
The narrowing causes wheezing, coughing, and difficulty
breathing. Heredity and environment play a role in the
onset of asthma. It the leading cause of serious illness
among children and can be life threatening. If treatment is
not started soon enough or medication isn’t taken properly,
it can lead to permanent damage to the lung tissue. Asthma
attacks can be triggered by respiratory infections, exercise,
emotional stress, and certain medications. There is no cure,
but it can be controlled by medications that smooth the
muscles around the airways, making it easier to breath.

92. REPRODUCTIVE SYSTEM
 Is the formation of new individuals.
 People can lead a normal life without reproducing.
 Could be thought of as the single most important system for the
continuation of a species.
 It produces, stores, and releases specialized sex cells known as
gametes.
 Neither the testes or the ovaries are capable of producing active
reproductive cells until puberty. Puberty - is a period of rapid
growth and sexual maturation during which the reproductive
system becomes fully functional. The onset of puberty occurs
between the ages of 9 and 15. Begins about one year earlier in
females than in males. Puberty begins when the hypothalamus
signals the pituitary to produce increased levels of follicle-
stimulating hormone(FSH) and luteinizing hormone (LH).

93. REPRODUCTIVE SYSTEM
 Male Reproductive System – FSH and LH
stimulates cells in the testes to produce testosterone.
FSH and testosterone stimulate the development of
sperm. The main function of the system is to provide
and produce sperm. Before or just after birth the
testes drop into the external sac called the scrotum.
Within each testis are clusters of hundreds of tiny
tubules called seminiferous tubules – are tightly
coiled and twisted together. Sperm are produced in
these tubules.

94. REPRODUCTIVE SYSTEM
 Male Reproductive System - Sperm then moves to
epididymis which is a structure in which the sperm fully
develop. From the epididymis, sperm are moved into a
tube called the vas deferens which extends upward
from the scrotum and eventually merges with the
urethra the tube that leads to the outside of the body
through the penis.
 About 2 to 6 milliliters of semen are released in an
average ejaculation. There are 50-130 million sperm in
1mL of semen.

95. REPRODUCTIVE SYSTEM

96. REPRODUCTIVE SYSTEM
 Female Reproductive System – primary organ is the
ovaries. They produce estrogen. The main function is
to produce ova. Also to prepare the female’s body to
nourish a developing embryo. Unlike the millions of
sperm produced each day in a male, the female on
produces one mature ovum, or egg, each month.
 Egg Development – each ovary contain about
400,000 primary follicles which are clusters of cells
that surround each egg. They help an egg mature.
Although a female is born with thousands of primary
follicles, only about 400 will be released.

97. REPRODUCTIVE SYSTEM
 Female Reproductive System
 Egg Release – after an egg has fully matured it is
released in a process called ovulation. The follicle
breaks open, and the egg is swept from the opening of
the ovary in the fallopian tubes. The egg moves from
the fallopian tubes after a few days, to the uterus. The
lining of the uterus is ready to receive a fertilized egg.
 The Menstrual Cycle – after puberty, the female body
goes through a complex series of events that lasts about
28 days. During the cycle, an egg develops and is
released from an ovary. The menstrual cycle has 4
phases: follicular phase, ovulation, luteal phase, and
menstration.

98. REPRODUCTIVE SYSTEM
 Follicular Phase – as a follicle develops, the cells
surrounding the egg enlarge and produce increased
amounts of estrogen. The estrogen level rises
dramatically and the lining of the uterus thickens in
preparation for a fertilized egg. The development of an
egg in this stage takes about 10 days.
 Ovulation – shortest phase lasting about 3 to 4 days.
The release of hormones causes the follicle to
rupture, and a mature egg is released in one of the
fallopian tubes.

99. REPRODUCTIVE SYSTEM
 Luteal Phase – the egg moves through the fallopian tubes
and the cells of the ruptured follicle changes its color to
yellow and is now known as the corpus luteum. It continues
to release estrogen but also begins to release progesterone.
In the first 14 days of the cycle, the increase of estrogen
levels stimulate cell growth and the lining of the uterus
thickens. Progesterone finishes the process by stimulating
the growth and development of the blood supply and
surrounding tissue. In the fist 2 days of this phase, the
chances of an egg fertilizing is the greatest.
 Menstruation – the egg will pass through the uterus without
implantation and the corpus luteum will disintegrate. The
lining of the uterus will detach from the wall and the tissue
and blood goes through the vagina. This phase lasts 3 to 7
days.

101. REPRODUCTIVE SYSTEM
 Fertilization – is the process of a sperm joining an egg. The
sperm and egg fuse together to form a single diploid (2N)
nucleus. A diploid cell contains a set of chromosomes from
each parent cell. A fertilized egg is called a zygote. To
prevent more than one sperm from attaching to the egg, the
egg releases the granules below its surface to form a barrier
around the egg.
 Development – 3 stages of early development:
implantation, gastrulation, and neurulation.
 Implantation – 6-7 days after fertilization, the blastocyst
attaches itself to the uterine wall. The embryo secretes
enzymes that digest a path into the wall. The specialization
process is called differentiation, is responsible for the
development of the body’s tissues.

102. REPRODUCTIVE SYSTEM
 Gastrulation – the blastocyst gradually sorts itself into 2
layers, which then gives rise to 3 layers. The 3rd layer is
produced by a process of cell migration known as gastrulation.
Forms the 3 layers: ectoderm, mesoderm, and endoderm.
These layers are the primary germ layers, because all the
organs and tissues form from them.
 Neurulation – the development of the nervous system.
 Placenta – formed by the chorionic villi and uterine lining. Is the
connection between the mother and developing embryo. Is the
embryo’s organ of respiration, nourishment, and excretion.
 After 8 weeks of development, the embryo is called a fetus.
After 3 months, most of the organs and tissues are developed.

103. REPRODUCTIVE SYSTEM DISORDERS
 Sexually Transmitted Diseases (STD) – infect millions of people
each year and accounting for thousands of deaths. The most
common is chlamydia. Puts females at risk of infertility due to
damage of the reproductive system. Other STDs are syphilis, which
can be fatal, and gonorrhea, which is easily spread by intercourse.
STDs can be caused by bacteria and viruses. Viral infections
cannot be treated with antibiotics.
 Ovarian Cancer - is the fifth most common cancer among
women, and it causes more deaths than any other type of female
reproductive cancer. The cause is unknown. Symptoms are often
vague such as: bloating or swollen belly area, Difficulty eating or
feeling full quickly, Pelvic or lower abdominal pain; the area may
feel "heavy" to you (pelvic heaviness), Abnormal menstrual
cycles, excessive hair growth that is coarse and dark, Sudden urge
to urinate, Needing to urinate more often than usual. Surgery is
used to treat all stages of ovarian cancer. Chemotherapy and
radiation are also used.