This document provides an overview of animal biology, covering topics like animal form and function, nutrition and transport, and feedback mechanisms. It begins by defining the subtopics to be covered in Module 1B, which are animal form and function, nutrition and transport, and feedback mechanisms in animals. The next sections provide details on animal anatomy, morphology, physiology, diversity of forms, and nervous and immune functions. It describes the body plans and characteristics of different animal phyla such as porifera, cnidaria, platyhelminths, nematodes, annelids, molluscs, echinoderms, arthropods, and chordates. Reproduction strategies like asexual and sexual reproduction are also summarized.
Ecosystem and their types ||Environmental Science||.pdf
Animal Biology.pdf
1. Prepared by: Samuel C. Brillo, MSc-Biology (cand.)
MODULE 1B
ORGANISMAL BIOLOGY:
ANIMAL BIOLOGY
2. Animal Biology consists of three subtopics:
• Module 1B.1 Animal Form and Function
• Module 1B.2 Animal Nutrition and Transport
• Module 1B.3 Feedback Mechanisms in Animals
4. • define animal anatomy, animal morphology, and animal
physiology
• describe diversity of animal forms
• illustrate different nervous and immune functions essential for
animals’ survival
6. Animal Morphoanatomy
Morphoanatomy - The study of
anatomical forms and structures
with emphasis on characteristics
useful in distinguishing the species.
9. Radial Symmetry -the organism can be divided into similar
halves by passing a plane at any angle along a central axis
Tripneustes ventricosus
Linckia laevigata
10. Asymmetry-not identical on both sides of a central line; unsymmetrical;
lacking symmetry
Leucosolenida botryoides
Clathrina clathrus
13. Phylum Porifera = Sponges
• Marine
• Body is made up of tiny pores
• 3 main parts: ostia, osculum, spongocoel.
• Asymmetrical
14. A spongocoel is the
large, central cavity of
sponges. Water enters
the spongocoel
through hundreds of
tiny pores called ostia
and exits through the
larger opening called
osculum.
General poriferan body plan
15. Spicules- each of the small needlelike or sharp-pointed structures of
calcite or silica that make up the skeleton of a sponge. It comes in
different sizes: Megascleres and microscleres.
Spongilla lacustris
17. Class Demospongiae
Most diverse; spicules are made
of spongin (a protein) or silica (a
mineral) or both.
Niphates digitalis
Class Sclerospongiae
Soft body covered by skeleton
made of calcium carbonate,
either aragonite or calcite.
Ceratoporella nicholsoni
18. Class Hexactinellida
Commonly known as glass
sponges, spicules are made of
silica.
Euplectella aspergillum
Class Calcarea
Calcareous sponges,
characterized by spicules made
out of calcium carbonate).
Clathrina clathrus
20. Phylum Cnidaria
• 10,000 species of animals found
exclusively in aquatic (freshwater and
marine) environments
• Cnidarians include true jellyfish, box
jellyfish, hydras, corals, sea anemones.
• They have radial symmetry.
21. Cnidarians undergo two life
stages: the polyp form, and
the medusa form.
Their body consists of three
layers: ectoderm,
endoderm, and mesoglea.
Ectoderm is called the
epidermis which covers
their body.
Mesoderm is called the
mesoglea; which is
nonliving, contains
water and fluids.
Endoderm is the innermost
layer, which is called
gastrodermis.
Gastrovascular cavity is
the space in their body
which the food is being
digested.
Tentacle is a slender flexible limb or appendage in an
animal, especially around the mouth of an invertebrate,
used for grasping, moving about, or bearing sense
organs.
Mouth is an opening where food and waste exits.
Basal disc is where
the polyp attaches its
body to a substrate.
22. Cnidocytes – are specialized cells in Cnidarians, also called “stinging
cells” which contains toxins. These cells are used to stun and capture
prey. Cnidocytes are contained in tentacles.
25. WORM PHYLA – large group of worms
1. Phylum Platyhelminthes (flatworms)
2. Phylum Nematoda (roundworms)
3. Phylum Annelida (segmented worms)
26. Phylum Platyhelminthes flatworms
• Body is flattened
• Has definitive head and tail region;
eyespots in head and has thick
cuticle outside the body.
• May be free-living or parasitic
Pseudobiceros hancockanus
Planaria sp.
28. Phylum Nematoda = roundworms
• Body is long, smooth, and
unsegmented.
• Cylindrical bodies are tapered at
both ends.
• Free-living or parasitic
Ascaris lumbricoides
Caenorhabditis elegans
29. Phylum Annelida = segmented worms; earthworm, leech
• Body is segmented internally and
externally;
• they have complete digestive system;
• tube within a tube body plan.
• Most are free-living
Hirudo medicinalis
Lumbricus terrestris
33. Phylum Mollusca = snails, shellfish, oysters, clams, octopus, squids,
cuttlefish
• Body is soft, unsegmented and has
strong muscular foot (in snail). Shell
can be external (in snails and
shellfish) or internal (in octopus).
Loligo vulgaris
Hapalochlaena lunulata
(blue ringed octopus)
39. Phylum Echinodermata = sea stars, sea cucumbers, sea
urchins, brittle stars, sea lilies
• Body is covered with spiny surface, with an internal skeleton inside
their body. These provide support and protection to the animal.
• They use their “tube feet” to move from one place to another.
47. Phylum Arthropoda = insects, crustaceans, spiders, scorpions,
millipedes, centipedes
• The phylum Arthropoda is by far
the largest of the phyla of the
kingdom Animalia, containing,
for example, insects,
crustaceans, and arachnids,
centipedes, millipedes.
51. SUBPHYLUM HEXAPODA, Class Insecta (insects) Divided into 2 subclasses:
Apterygota (wingless insects) and Pterygota (winged insects)
52. General insect body plan
Wasp Grasshopper
CHARACTERISTICS
• Have legs and some have wings
• Found in all environments
• 3 main parts: Head, Thorax, Abdomen
55. Phylum Chordata
CHARACTERISTICS:
1. Single, hollow nerve cord beneath dorsal surface; in vertebrates, it differentiates into brain and
spinal cord.
2. Notochord: flexible rod on the dorsal side of gut, present at one stage in all chordates; displaced
in vertebrates by vertebral column that forms around the nerve cord.
3. Pharyngeal slits (pouches) connect pharynx (between mouth and esophagus) with outside gills in
sharks, fish; present in terrestrial animal embryos but disappear later except Eustachian tube
(connecting throat and middle ear)
4. Postanal tail extends beyond anus; present at least in embryo; regresses into tail bone in humans
5. Segmentation: reflected in arrangement of muscles (somites) and in vertebral column (both
mesoderm)
56. Anatomy of a primitive chordate. All animals belonging to Phylum Chordata
possesses these characteristics. However, during the course of development,
these parts begin to modify or change.
60. Class Amphibia (amphibians)
This group of animals include salamanders,
newts, frogs, toads, and caecilians.
• Many amphibians, such as frogs, undergo
a metamorphosis, meaning they begin life
in the water and live on land as adults.
• Defining characteristics of these creatures
include moist, scaleless skin and the fact
that they are cold-blooded.
64. Class Reptilia (reptiles)
This group of animals include alligators,
crocodiles, lizards, iguanas, chameleons,
turtles, tortoises, snakes, cobras, and vipers.
• The first and foremost characteristic of the
reptiles is that are cold blooded.
• They are able to regulate their inner body
temperature to the temperature of the
environment.
• They have scaly skins but absence of hair
or fur. The scales of the reptiles develop
as a surface cells filled with Keratin.
69. Class Aves (birds)
This group of animals include flying and non-
flying birds.
All birds have the same characteristics:
• Feathers that covers the body, which grow
in their skin.
• Wings
• Lightweight skeleton
• Endothermic (warm blooded)
• Lungs with air sacs
• Beak
71. Class Mammalia
(mammals)
All mammals share the following
characteristics:
• Mammary Glands
• Hair
• Jaw and ear bones
• 4-chambered heart and
diaphragm
• Complex brain functions
75. Asexual reproduction –
individuals are exact
clones of the parent with
identical genetic makeup.
Sexual reproduction –
individuals are formed
from the combination of n
gametes to form a
genetically unique
offspring (variety)
Asexual vs. Sexual reproduction
77. Types of Asexual Reproduction
•Regeneration
•Budding
•Parthenogenesis
78. Regeneration
• Involves the production and
differentiation of new tissues to
replace missing and damaged
parts of the body.
• Cellular replication by mitosis,
followed by differentiation
81. Budding
• Involves forming of new individual
from an outgrowth or ‘bud’ on the
parent’s body.
• It doesn’t involve any sex organs.
• Common in Hydra and polyps
• If not detached from parent’s
body, it might grow into a colony.
83. • Involves an activated unfertilized
egg that undergoes mitosis in the
absence of cytokinesis
• Two nuclei fuse together to form
2n nucleus then further develop
as if it had been fertilized.
• E.g., aphids (Aphididae), bees
(Apidae), wasps (Vespidae) and
ants (Formicidae),
few species of vertebrates e.g.,
Bynoe’s gecko (Heteronotia binoei)
Parthenogenesis
87. Monoecious vs. Dioecious Organisms
• Monoecious:
Also called Monoecism,
Having male and female sex
organs in the same
individual (also called
hermaphroditic)
• Dioecious:
Also called Dioecism, Having
male reproductive organs in
one individual and female in
another
88. Self-Fertilization vs. Cross-Fertilization
• Self-Fertilization:
Fertilization effected by union
of egg cell and sperm cell
from the same individual.
• Cross-Fertilization:
Fertilization in which gametes
are produced by separate
individuals or sometimes by
individuals of different kinds
89. Animal Reproductive Development
• Protandry (male to female) vs.
Protogyny (female to male)
e.g. Amphiprion ocellaris
Sequential hermaphroditism
occurs when the individual
changes sex at some point in its
life.
90. Animal Reproductive Development
Indirect development
• Involves one or more
intermediate larval forms
before the adult form is
attained.
• Occurs mostly in
invertebrates
• Metamorphosis present
Direct development
• Offspring hatch or are born in
miniature adult form.
• Occurs mostly in vertebrates
• Metamorphosis absent
95. Gonads
• Sex organs
• Produce hormones that regulate the development of
gametes and 2ndary sex organs act as pheromones and
produce sexual differences in appearance and behavior.
96. Gametic development
Spermatogenesis
• Testes; testosterone
• Spermatogenesis is the
process in which an animal
produces spermatozoa from
PGC by way of mitosis and
meiosis.
Oogenesis
• Ovaries; estrogen
• Oogenesis is the process in
which an animal produces
oogonia from PGC by way of
mitosis and meiosis.
What is PGC?
The primordial germ cells are the
common origins of spermatozoa
and oocytes and thus represent
the ancestors of the germline.
102. NOTE:
• The nervous system allows body to respond
quickly to changes in the environment by
gathering information, transmitting, and
processing information to determine the best
response, and sending information to muscles,
glands, and organs so they can respond correctly.
102
104. Nervous system of Hydra
In Hydra, nerve nets are
diffused all over the body
to control the contraction
of the gastrovascular
cavity or the gastrocoel.
105. • CEPHALIZATION- the onset
of cephalization marks a more
complex nervous system.
In simple cephalized animals (ex:
Planaria) a simple central
nervous system or CNS with a
small brain and longitudinal
nerve cords is present.
Nervous system of Planaria
Remember that Planaria is a flatworm (Platyhelminth)
106. • In more complex invertebrates like
annelids and arthropods, the
nervous system is divided into two
regions: the CNS and PNS.
• CNS or Central Nervous System
is composed of brain and ventral
nerve cords with clusters of
neurons called ganglia.
• The rest of the nerves in animal’s
body is the PNS or peripheral
nervous system.
Nervous system of Annelids and Arthropods
110. 110
1. Somatic Nervous System (voluntary)
• Relays information from skin, sense organs &
skeletal muscles to CNS
• Brings responses back to skeletal muscles for
voluntary responses
2. Autonomic Nervous System (involuntary)
• Regulates bodies involuntary responses
• Relays information to internal organs
• Two divisions:
A. Sympathetic nervous system – in times of
stress
➢ Emergency response
➢ Fight or flight
B. Parasympathetic nervous system – when
body is at rest or with normal functions; Normal
everyday conditions
117. NOTE:
• Immune system is responsible for defending
organisms from pathogens such as:
✓ Viruses: Ebola, rabies, HIV, HPV
✓ Bacteria: E. coli, Salmonella, Staphylococci
✓ Fungi: Trichophyton, Candida
✓ Systemic: cancer cells
117
118. • There are two major lines
of defense: innate
immunity and
acquired/adaptive
immunity.
118
119. How does our body defend
ourselves against diseases?
119
120. Innate immunity
• Nonspecific response to a broad range of microbes
• Formed by skin and mucous membrane accompanied by
macrophages and other phagocytic cells
121. Innate immunity
There are two lines of defense under innate
immunity:
First line Second line
Skin and mucous membrane,
Acts as barrier on invading
pathogens
Chemical defense, done
through phagocytosis
Lines the digestive tract,
respiratory and genitourinary
tract
Inner lining of organs / tracts
122. First line of defense
➢ Skin is acidic: pH ~3.5 – kills pathogenic
microorganisms
123. Sweat, tears, saliva
contain lysozyme, an
enzyme that kills bacteria.
FIRST LINE OF DEFENSE
Minor abrasion can cause
pathogens to enter the body,
which is in the inner linings of
organs or tracts (eg. Digestion,
respiration) -> leads to
secondary line of
defense
124. ➢ Once the pathogen invade
the lining of organisms,
chemical defense
mechanism occurs ->
which is done through
phagocytosis.
Phagocytes, the cells responsible for phagocytosis
attach to their opponent (pathogen) via surface receptor
of pathogens then engulf it, forming a vacuole that fuses
with lysosome.
Lysosomes contain chemicals and enzymes which
destroys the pathogen.
SECONDARY LINE OF DEFENSE
125. Secondary line of defense
➢ However, some pathogens have polysaccharide
capsule which is resistant to lytic enzymes or to
phagocytes.
➢ They can escape the first and second line of
innate immunity – which can trigger the next line
which is INFLAMMATORY RESPONSE.
126. Inflammatory response
➢ Triggers many responses such as:
➢ Dilation of blood vessel: which allows more
blood to flow in. Affected cells in the area
release hormone called histamine.
✓ What is the use of histamine?: to relax
blood vessel to allow more blood flow.
➢ Fever: high blood temp. can occur which can
hinder bacterial growth. Lymphatic system is
activated at this moment.
128. Acquired immunity
How does it work?
• Lymphocyte provides specific defense against
pathogens.
• The body detects antigen, which is either: a
foreign object, molecule or invading
pathogens.
• The immune system now will produce
antibodies: which will attach to the antigens.
129. Acquired immunity
How does it work?
• Our body produces two types of cells for
acquired immunity to work. These are:
1. B cells
2. T cells
130. Acquired immunity
• B cells: produces antibodies, if there is
an antigen, it triggers the production of B cells
in our body.
• Only B cells that produce the antigen-
antibody response is selected for future
propagation when similar invader is
present!
133. Acquired immunity
• B cells: are produced by lymphatic system,
which stores B cells and memory B cells.
134. Acquired immunity
• T cells: attacks infected cells through
phagocytosis or by injecting chemicals called
perforins to break down and kill the pathogen.
135. Acquired immunity
• There are three types of T cells:
1. Killer T cells: injects chemicals to
pathogens
2. Helper T cells: attracts and assists B
cells in antibody production
3. Suppressor T cells: stop B and T
cells after infection
137. B and T cells
are produced
in the bone
marrow, and
site of
maturation
dictates the
fate of cell.
cell.
Example: maturation in bone marrow forms B cells and
maturation in lymph forms T cell
147. NOTE:
• A skeletal system is necessary to support the
body, protect internal organs, and allow for the
movement of an organism. There are three
different skeleton designs that provide
organisms these functions: hydrostatic skeleton,
exoskeleton, and endoskeleton.
147
148. HYDROSTATIC SKELETON
• A hydrostatic skeleton is one formed by a fluid-filled
compartment within the body: the coelom. The organs of the
coelom are supported by the aqueous fluid, which also resists
external compression.
• This compartment is under hydrostatic pressure because of the
fluid and supports the other organs of the organism.
• This type of skeletal system is found in soft-bodied animals such
as sea anemones, earthworms, Cnidaria, and other invertebrates.
148
149. 149
Hydrostatic skeleton: The skeleton of the red-knobbed
sea star (Protoreaster linckii) is an example of a
hydrostatic skeleton.
150. EXOSKELETON
• An exoskeleton is an external, hard, encasement on the surface of an
organism. For example, the shells of crabs and insects are exoskeletons.
• This skeleton type provides defense against predators, supports the body,
and allows for movement through the contraction of attached muscles.
• Arthropods, such as crabs and lobsters, have exoskeletons that consist of
30–50 percent chitin, a polysaccharide derivative of glucose that is a
strong-but-flexible material. Chitin is secreted by the epidermal cells.
• The exoskeleton is further strengthened by the addition of calcium
carbonate in organisms such as the lobster. Because the exoskeleton is
acellular and does not grow as the organism grows, arthropods must
periodically shed their exoskeletons.
150
153. ENDOSKELETON
• An endoskeleton consists of hard, mineralized structures located within the soft
tissue of organisms.
• The bones of vertebrates are composed of tissues, whereas sponges have no true
tissues.
• Endoskeletons provide support for the body, protect internal organs, and allow
for movement through contraction of muscles attached to the skeleton.
153
154. 154
Endoskeletons: The skeletons of humans and horses
are examples of endoskeletons. They provide bodies
with support, protection of organs, and aid in movement.
155. 155
• The human skeleton is an endoskeleton
that consists of 206 bones in the adult. It
has five main functions: supporting the
body, storing minerals and lipids,
producing blood cells, protecting internal
organs, and allowing for movement.
• The skeletal system in vertebrates is
divided into the axial skeleton (which
consists of the skull, vertebral column, and
rib cage = total of 80 bones), and the
appendicular skeleton (which consists of
the shoulders, limb bones, the pectoral
girdle, and the pelvic girdle = total of 126
bones).
159. 159
Appendicular skeleton: The appendicular skeleton is
composed of the bones of the pectoral limbs (arm, forearm,
hand), the pelvic limbs (thigh, leg, foot), the pectoral girdle,
and the pelvic girdle.
163. NOTE:
• The muscular system controls numerous
functions, which is possible with the significant
differentiation of muscle tissue morphology and
ability.
163
166. 166
Skeletal Muscle Tissue
• Skeletal muscle mainly attaches to the skeletal system via tendons to
maintain posture and control movement. For example, contraction of the
biceps muscle, attached to the scapula and radius, will raise the forearm.
Some skeletal muscle can attach directly to other muscles or to the skin,
as seen in
the face where numerous muscles control facial expression.
• Skeletal muscle is under voluntary control, although this can be
subconscious when maintaining posture or balance. Morphologically
skeletal myocytes are elongated and tubular and appear striated with
multiple peripheral nuclei.
167. 167
Cardiac Muscle Tissue
• Cardiac muscle tissue is found only in the heart, where cardiac
contractions pump blood throughout the body and maintain blood
pressure.
• As with skeletal muscle, cardiac muscle is striated; however it is not
consciously controlled and so is classified as involuntary. Cardiac
muscle can be further differentiated from skeletal muscle by the
presence of intercalated discs that control the synchronized
contraction of cardiac tissues. Cardiac myocytes are shorter than
skeletal equivalents and contain only one or two centrally located
nuclei.
168. 168
Smooth Muscle Tissue
• Smooth muscle tissue is associated with numerous organs and tissue
systems, such as the digestive system and respiratory system. It plays an
important role in the regulation of flow in such systems, such as aiding the
movement of food through the digestive system via peristalsis.
• Smooth muscle is non-striated and involuntary. Smooth muscle myocytes
are spindle shaped with a single centrally located nucleus.
169. Hoefenagels, M. Biology: Concepts and Investigations. McGraw-Hill, 2017.
Mader, S.S. Concepts of Biology. McGraw Hill Publishing, 2014.
Miller, S. & Harley, J. Zoology 10th edition. McGraw-Hill, 2016.
Rea, M.A. & Dagamac, N.H. General Biology 2. REX Book Store, 2017.
https://www.researchgate.net/publication/299542613_An_Introduction_to_Zoology
https://www.academia.edu/36439722/Hickman_-_Zoology_14th_ed.pdf
https://www.academia.edu/36439722/Hickman_-_Zoology_14th_ed.pdf
https://web.duke.edu/histology/MBS/Videos/Phys/Phys%201.2%20Homeo%20Reg/Phys%201.2%20and%
201.2%20Homeo%20Fluid%20Compartments%20and%20Reg%20NOTES.pdf
171. • define plant nutrition and transport
• describe the structure of organs and tissues involved in plant
transport
• illustrate pathways of nutrients throughout plants
173. NOTE:
• Animals are heterotrophic; meaning, they cannot
make their own food.
• In order to survive, animals must bring nutrients
from the food to the body cells.
• It is the job of digestive system to break down
large, complex molecules to small, simpler
molecules absorbable by cells.
173
174. “Animals can be classified
into two: invertebrates and
vertebrates. These two
have different ways of
digesting their food.”
174
176. GASTROVASCULAR CAVITY (GVC)
• Animals having gastrovascular cavity include Platyhelminthes
and Cnidaria.
• They digest their food a tube or cavity with only one opening
that serves as both mouth and anus.
• Ingested materials enter the mouth and pass through the
cavity, where digestive enzymes are secreted to break down
the food.
• The cells lining the cavity engulf the food particles.
176
183. ALIMENTARY CANAL
• Some invertebrates like earthworms (Annelida: Oligochaeta)
and insects (Arthropoda: Insecta) have alimentary canal.
• Alimentary canal is a pathway which receives food through
mouth on one end and eliminates wastes through the anus on
another.
• It consists of the mouth, esophagus, crop, gizzard, intestines,
and anus.
183
Lumbricus terrestris
Periplaneta americana
184. 184
Digestive System of Insect (Insecta)
Tettigonia viridissima
The insect’s body is
divided into three major
divisions:
head, thorax, and
abdomen.
185. 185
Digestive System of Earthworm (Oligochaeta)
The earthworm is made of
about 100-150 segments.
Segmented body parts provide
important structural functions.
Megascolides australis
187. MONOGASTRIC DIGESTIVE SYSTEM
• Consists of single stomach chamber.
• Physical and chemical digestion begins in mouth.
• A monogastric digestive system works as soon as the food enters the mouth.
• Examples of animals with monogastric digestive system are humans (omnivore),
cats (carnivore), and rabbits (herbivore).
187
Homo sapiens Oryctolagus cuniculus
Felis catus
188. Mastication – (chewing) process by
which food is broken down in mouth,
mechanically.
Ingestion – process by which
animals take in food using their
mouth.
189. 189
Mouth must be moistened with
saliva.
Saliva contains ptyalin, an
enzyme which helps break down
carbohydrates in food.
190. 1. Enzymes in saliva hasten
chemical reactions in the mouth;
breaking down complex substances
into simpler ones.
2. Tongue will push the food, (process of gulping) to esophagus.
Food moves down in this tube to the stomach through peristalsis
(contraction of smooth muscles). Epiglottis must close the throat when
gulping to avoid food or liquid from entering the lungs.
3. In the stomach, food
continues to be digested by
HCl, enzymes and
digestive juices. Stomach
carry out peristalsis. In 3-4
hours, the food will become
a chyme before going to
SI.
4. The villi in SI lining
(called epithelia), absorb
the nutrients in food. Along
with the bile from the liver
and pancreatic juices,
they help break down fats,
proteins and starches.
5. Remaining water, nutrients and
undigested food will be stored in
large intestine.
Through process of defecation,
undigested food called feces will
be excreted. (rectum to anus)
The Process of Digestion
The main job of liver is to filter the
blood coming from the digestive
tract, before passing it to the rest of
the body. The liver detoxifies
chemicals and metabolizes drugs. As
it does so, the liver secretes bile that
ends up back in the intestines.
191. AVIAN DIGESTIVE SYSTEM
• Birds (Aves) do not have teeth. Their beak/bill/rostrum serves as their
mouth.
• Birds do not masticate their food.
• Crop, proventriculus, and gizzard.
191
Lonchura atricapilla
Pithecophaga jefferyi
Struthio camelus
Cacatua haematuropygia
Anas luzonica
192. 192
Digestive System of Chicken (Aves)
Gallus gallus domesticus
Food is stored in
crop.
Gastric juices
are secreted
to digest the
food.
Where the food is
mechanically
ground.
Absorption
Absorption
Exits waste
Flightless birds are heavier
than birds that can fly. This is
because flying birds have
higher metabolism.
193. RUMINANT DIGESTIVE SYSTEM
• Polygastric, meaning the stomach has multiple compartments:
rumen, reticulum, omasum, and abomasum.
• Diet of ruminants (herbivores) consists largely of roughage or
fiber, their digestive system enables them to break down
cellulose (main component or rigid cell wall in plants).
193
Capra aegagrus hircus
Bos taurus Ovis aries
194. 194
Digestive System of Cow (Ruminantia)
1st: RUMEN. Largest chamber,
contains bacteria that promote
fermentation, and break down food.
2nd: RETICULUM.
Small pouch that
traps foreign
materials which the
ruminant animal
may have
swallowed.
3rd: OMASUM. Grinds the
food and removes water
from it.
4th: ABOMASMUM. Serves as “true”
stomach in that it functions similarly
as the stomach of monogastric
animals.
Bacteria found in rumen of most
ruminants are Cellulomonas,
which secretes cellulases which
breaks down cellulose.
Some bacteria also exist are:
Fibrobacteres, Klebsiella,
Bacteroides, and Oxalobacter.
195. PSEUDO-RUMINANT DIGESTIVE SYSTEM
• Stomach has three chambers: reticulum, omasum, and abomasum.
• Diet: roughage, fiber, forages, grains (mainly herbivorous)
• Has enlarge cecum where food is fermented and digested.
• Also relies on microbial support for digestion.
• Camels, horses, rabbits, guinea pigs
195
Cavia porcellus
guinea pig
Camelus dromedarius
Arabian camel
Equus caballus
horse
198. NOTE:
• Respiratory system consists of organs that allow
gas exchange. It brings oxygen in the body cells of
animals and eliminates carbon dioxide, which is a
waste product of cells.
198
199. • Respiration occurs
through respiratory
organs of animals which
include skin, gills,
tracheal system, and
lungs.
199
200. Have you ever wondered why
earthworms are red?
Have you ever wondered why
can they survive below the
ground?
200
201. GAS EXCHANGE THROUGH SKIN
• Animals using integumentary system (or their skin) include amphibians and
earthworms.
• It allows gas exchange between the external environment and circulatory
system due to the network of capillaries that lie below the skin.
201
Limnonectes magnus (formerly
Rana magna)
Giant Philippine frog
Bufo marinus
Marine toad
Alcalus mariae
Palawan Eastern frog
Ichthyopis mindanaoensis
Mindanao island caecilian
202. 202
Gas Exchange in Earthworms (Oligochaeta)
Earthworms (Lumbricus
terrestris) are able to survive
below the soil. In the environment,
from air or water, oxygen moves
through a thin, moist body wall of
vessels
204. GAS EXCHANGE THROUGH GILLS
• Fish and other aquatic organisms use their gills to take up
oxygen dissolved in the water and diffuse CO2 out of the
bloodstream.
204
Decapterus macarellus
Galunggong
Chanos chanos
Milkfish
Oreochromis niloticus
Nile tilapia
Sardinella tawilis
Tawilis (only in Taal lake)
Carassius auratus
Goldfish Rhincodon typus
Butanding
206. Gills
Animals with this type of respiration
uses their gills to breathe.
Dissolved oxygen in water is
readily diffused into the gill
membranes and allows carbon
dioxide to be expelled to the water.
2 types of gills:
(1) Internal
(2) External
207. GAS EXCHANGE THROUGH TRACHEA
Instead of lungs, insects breathe with a network of tiny tubes
called tracheae. Air enters the tubes through a row of holes along
an insect's abdomen called spiracles. The air then diffuses down
the blind-ended tracheae. The tracheoles are the sites of gas
exchange.
208. • Lungs- pair of organs divided into small chambers filled
with capillaries.
• When inhaling, there is a decrease in pressure around
lungs, causing air to breathe in. The ribcage expands, and
moves diaphragm downward.
• When exhaling, there is an increase in pressure around
lungs and force air out of respiratory tract. The ribcage
contracts and moves diaphragm upward.
GAS EXCHANGE THROUGH LUNGS
209. In humans, chest cavity is bisected by
the trachea, a tube that connects the
nose and mouth to the lungs.
Bronchi is subdivided into
bronchioles Under the lungs is the dome
shaped muscle called the
diaphragm.
Lungs are enclosed in rib cage,
which serves to protect both lungs
and heart.
General Mechanism of Respiration
Air enters the body through
the nasal cavity.
In the tip of bronchioles are
alveoli (also called air sacs)
Alveoli are the main sites of gas
exchange; it contains pulmonary
capillaries which diffuses in
oxygen and CO2 out.
Trachea
divides into
two main
bronchi; left
and right
bronchus.
213. Do animals have the same
number of heart, heart
chambers, and number of
circuits through which blood
flows?
213
214. SINGLE-LOOP CIRCUIT
• Two-chambered heart pumps the blood to the gills to be re-
oxygenated (via gill circulation), then blood flows to the rest of the
body and back to the heart (via systemic capillaries)
214
Amphiprion ocellaris
Ocellaris clownfish
Selar crumenophthalmus
Matang-baka
Caesio cuning
Dalagang bukid
Pterigoplichthys pardalis
Janitor fish (Amazon sailfin
catfish)
215. DOUBLE-LOOP CIRCUIT
• In amphibians, reptiles, birds,
and mammals blood flow is
directed into two circuits: one
through the lungs and one
back to the heart (via
pulmonary circulation) and the
other throughout the rest of
the body and its organs, which
also includes the brain (via
systemic circulation).
215
217. Two Types of Double-Loop Circuit:
1. Double-Loop Circulatory System with 3-Chambered Heart
2. Double-Loop Circulatory System with 4-Chambered Heart
217
Naja philippinensis
Philippine cobra
Manis culionensis
Philippine pangolin
223. NOTE:
• Excretory system provides a mechanism for the
elimination of various wastes from the body.
223
224. • The wastes such as
excess water and salts,
carbon dioxide, and urea
are removed from the
body by the organs of the
excretory system.
224
225. How do animals remove
excess waste inside their
body?
225
226. EXCRETORY SYSTEMS OF INVERTEBRATES
There are three common ways
invertebrates remove waste.
These are through their:
• Protonephridia (flame
cells)
• Nephridia
• Malpighian Tubules
226
FLAME CELLS
Planaria (flatworms) live in fresh water. Their excretory system consists of two tubules connected to a
highly-branched duct system that leads to pores located all along the sides of the body. The filtrate is
secreted through these pores (called protonephridial pores). The cells in the tubules are called flame
cells (or protonephridia) because they have cluster of cilia that looks like a flickering flame when
viewed under the microscope.
227. EXCRETORY SYSTEMS OF INVERTEBRATES
There are three common ways
invertebrates remove waste.
These are through their:
• Protonephridia (flame
cells)
• Nephridia
• Malpighian Tubules
227
NEPHRIDIA
In earthworms (Lumbricus),
nephridia are more evolved than
flame cells because they can
reabsorb useful metabolites before
excretion of waste. These are called
metanephridia. A pair of
metanephridia is present on each
segment. They are similar to flame
cells, in that they have tubules with
cilia and function like a kidney to
remove wastes.
228. EXCRETORY SYSTEMS OF INVERTEBRATES
There are three common ways
invertebrates remove waste.
These are through their:
• Protonephridia (flame
cells)
• Nephridia
• Malpighian Tubules
228
MALPIGHIAN TUBULES
The Malpighian tubules remove
wastes from insects (Class Insecta)
by producing urine and solid
nitrogenous wastes, which are then
excreted from the body.
Paraponera clavata
Bullet ant
229. Hoefenagels, M. Biology: Concepts and Investigations. McGraw-Hill, 2017.
Mader, S.S. Concepts of Biology. McGraw Hill Publishing, 2014.
Miller, S. & Harley, J. Zoology 10th edition. McGraw-Hill, 2016.
Rea, M.A. & Dagamac, N.H. General Biology 2. REX Book Store, 2017.
https://www.researchgate.net/publication/299542613_An_Introduction_to_Zoology
https://www.academia.edu/36439722/Hickman_-_Zoology_14th_ed.pdf
https://www.academia.edu/36439722/Hickman_-_Zoology_14th_ed.pdf
https://web.duke.edu/histology/MBS/Videos/Phys/Phys%201.2%20Homeo%20Reg/Phys%201.2%20and%
201.2%20Homeo%20Fluid%20Compartments%20and%20Reg%20NOTES.pdf
231. • define feedback mechanisms and homeostasis
• differentiate positive and feedback mechanisms
• illustrate different feedback mechanisms required for animal’s
survival, such as thermoregulation and osmoregulation
233. NOTE:
• The endocrine system is the collection of glands
that produce hormones that regulate
metabolism, growth and development, tissue
function, sexual function, reproduction, sleep,
and mood, among other things.
233
234. • Hormones are chemical
substances produced by
endocrine gland. They are
transported into the circulatory
system to target organs where
they exert their functions.
234
Hormones play a vital role in regulating bodily functions.
253. Hoefenagels, M. Biology: Concepts and Investigations. McGraw-Hill, 2017.
Mader, S.S. Concepts of Biology. McGraw Hill Publishing, 2014.
Miller, S. & Harley, J. Zoology 10th edition. McGraw-Hill, 2016.
Rea, M.A. & Dagamac, N.H. General Biology 2. REX Book Store, 2017.
https://www.researchgate.net/publication/299542613_An_Introduction_to_Zoology
https://www.academia.edu/36439722/Hickman_-_Zoology_14th_ed.pdf
https://www.academia.edu/36439722/Hickman_-_Zoology_14th_ed.pdf
https://web.duke.edu/histology/MBS/Videos/Phys/Phys%201.2%20Homeo%20Reg/Phys%201.2%20and%
201.2%20Homeo%20Fluid%20Compartments%20and%20Reg%20NOTES.pdf