The circulatory system transports oxygenated blood from the heart to organs via arteries and arterioles, and deoxygenated blood is returned to the heart via veins and venules. The heart has its own blood supply through the coronary circulation. Blood pressure is a measure of the force used to pump blood around the body and is measured using a sphygmomanometer. Haemoglobin is a protein that carries oxygen in red blood cells and can bind up to four oxygen molecules at a time to transport oxygen around the body.
2. Learning
objectives
Understand the circulatory system and blood
vessels, including arteries, veins, and capillaries.
Understand coronary circulation and that the
heart has its own blood supply
Understand what systemic arterial pressure
(blood pressure) is
Understand the cardiovascular disease and its
diagnostic tests
Understand why haemoglobin is an oxygen-
transporter in the body
Apply the knowledge learned in the Kahoot
3. pulmonary vein, renal artery, mesenteric artery, hepatic vein,
hepatic portal vein, hepatic artery, renal vein, pulmonary artery
Organs Oxygenated
blood
Deoxygenated
blood
Kidney enter via leave via
Gut enter via leave via
Liver enter via leaves via
Lungs leave via enter via
Filling in the gaps:
4. Organs Oxygenated blood Deoxygenated blood
Kidney enter via leave via
Gut enter via leave via
Liver enter via leaves via
Lungs leave via enter via
renal artery
pulmonary
artery
renal vein
mesenteric
artery
pulmonary
vein
hepatic portal
vein
hepatic
artery
hepatic vein
5. • All arteries carry blood away …..........................
• All veins carry blood ….............................
• Arteries carry ..................... blood except from the.....................
• Veins carry ................... blood except from the ….....................
• The main function of the circulatory system is to deliver …........
and ….................. to the rest of the body from the heart.
Refresh your memory!
What is the
circulatory
system?
Systemic circulation is made up of the
heart and blood vessels.
To the heart/pulmonary artery/nutrients/oxygen/from the
heart/oxygenated/deoxygenated/pulmonary vein
from the heart
towards the heart
oxygenated Pulmonary arteries
deoxygenated Pulmonary veins
nutrients
blood
7. Arteries and arterioles
Elastic arteries (aorta) - large diameter, low resistance. A large
amount of elastin, smooth muscle and folded endothelium allows the
artery to stretch and recoil to maintain high pressure.
Muscular arteries – deliver blood to specific organs, less elastin and
more smooth muscle, therefore less distensible, more active
on vasoconstriction.
Arterioles – deliver to capillary beds by responding to stimuli from the
brain and local chemicals, mostly smooth muscle that contract to
restrict blood flow or relax to allow full blood flow.
8. Continuous capillaries
• The most common type of capillaries
• Delivers blood to the organ
• Endothelial cells have tight junctions between them
• Contain intercellular clefts: allow the limited passage of fluid and small solutes
• Play a role in active absorption or filtrate
formation (small intestine, kidney)
• Endothelial cells of the vessel have oval pores or
fenestrations
• Most permeable to fluids and small solutes
Fenestrated capillaries
9. • Blood flows through the capillary beds which is
called …...................
• Capillaries form..........................that are
interweaving networks.
• Precapillary sphincters..............or..............to control blood flow
capillary beds
contract relax
microcirculation
Capillary beds/ relax/contract/microcirculation
10. Venules
• Formed when capillaries unite to get the deoxygenated blood out of the organ
• Consists mainly of endothelium
• Larger venules have a sparse smooth muscle and connective tissue
• Carry large volumes of blood back to the heart
• Valves inside veins stop blood flowing backwards
• Blood flows at low pressure
• Consist of 3 layers: endothelium, smooth muscle, connective
tissue
• Inner walls are always thinner than arteries
• Lumens are always larger than arteries
• Not a lot of elastin or muscle tissue
Veins
11. What is the coronary circulation?
• The coronary circulation
supplies the heart with blood.
• The heart has it’s own blood
supply with the left and right
coronary artery.
• The right and left coronary
arteries arise from the base of
the aorta, just above the aortic
valve.
• Most of the venous blood drains
via the coronary sinus directly
into the right atrium.
12. Systemic blood pressure
What is pressure?
'Blood pressure is a measure of the force that your heart uses to pump
blood around your body.' (NHS)
Measured in millimetres of mercury (mmHg) and is given as 2 figures:
• Systolic pressure = the pressure when your heart pushes blood out
• Diastolic pressure = the pressure when your heart rests between beats.
• Ideal blood pressure: between 90/60mmHg and 120/80mmHg
• High blood pressure: 140/90mmHg or higher
• Low blood pressure: 90/60mmHg or lower
13. How is blood pressure measured?
Systemic arterial blood pressure is measured using a Sphygmomanometer.
14. Cardiovascular disease
DEFINITION: Pathological conditions affecting the heart and blood vessels.
Changes/adaptations in your cardiovascular system when exercising, during
pregnancy and in extreme environmental conditions
Conditions include strokes, arrythmias, coronary heart disease
Leading cause of death globally, estimate at 32% of all deaths
Globally 1 in 14 people are living with a heart or circulatory disease
85% of CVD patients are a result of heart attacks and strokes
Risk factors for CV disease:
• Unhealthy diet (high blood cholesterol)
• High blood pressure
• Cigarette smoking
• Genetic predisposition
• Physical inactivity
15. Common tests for CV disease
A complete blood count (CBC)
Cardiac Tn - troponin test
Blood test -
measures levels of other substances
Echocardiogram (ultrasound) -
elicits an x-ray picture of the heart
Electrocardiogram (ECG) -
ECG reads your heart’s electrical impulses
16. Haemoglobin
Haemoglobin is a protein that carries
oxygen in blood vessels around the
body
Structure of haemoglobin
• Each chain has a haem group which
contains an iron ion and gives
haemoglobin it’s red colour
17. Haemoglobin – High affinity for oxygen
Each molecule of haemoglobin can
carry 4 oxygen molecules
• At high oxygen concentration in
the lungs: oxygen binds
to haemoglobin in red blood cells
and forms oxyhaemoglobin.
• At low oxygen concentration in
the organs: oxyhaemoglobin turns
into haemoglobin.
18. Summary
• The circulatory system is important as it delivers oxygen and nutrients to
the rest of the body through the blood
• Oxygenated blood is transported from the heart to organs via the arteries
and arterioles
• Deoxygenated blood is transported from the organs via the veins and venules
back to the heart
• The heart has its own blood supply via the coronary circulation
• Blood pressure is a measure of the force that your heart uses to pump blood
around your body and it is measured using a sphygmomanometer
• Examples of diagnostic tests for CV include blood count, blood tests and
ECG.
• Haemoglobin is a protein that can carry up to 4 molecules of oxygen in blood
vessels around the body
19. To finish off!
Join this Kahoot and complete the questions!
Link:https://create.kahoot.it/details/5f0b9269-db9f-42a5-
bcc1-e5b35319e171
Editor's Notes
Mark
Mark
https://medlineplus.gov/lab-tests/troponin-test/
https://www.healthywa.wa.gov.au/Articles/A_E/Common-medical-tests-to-diagnose-heart-conditions
https://www.mayoclinic.org/tests-procedures/complete-blood-count/about/pac-20384919
Echocardiogram (ultrasound) - echocardiogram is a common test. It gives a picture of your heart using ultrasound, a type of X-ray. It uses a probe either on your chest or down your oesophagus (throat).
Electrocardiogram (ECG) - ECG reads your heart’s electrical impulses. It shows how well your heart is beating.
A complete blood count (CBC) is a blood test used to evaluate your overall health and detect a wide range of disorders, including anemia, infection and leukemia.
A complete blood count test measures several components and features of your blood, including:
Red blood cells, which carry oxygen
White blood cells, which fight infection
Hemoglobin, the oxygen-carrying protein in red blood cells
Hematocrit, the proportion of red blood cells to the fluid component, or plasma, in your blood
Platelets, which help with blood clotting
Cardia Tn - troponin test measures the level of troponin in your blood. Troponin is a type of protein found in the muscles of your heart. Troponin isn't normally found in the blood. When heart muscles become damaged, troponin is sent into the bloodstream. As heart damage increases, greater amounts of troponin are released in the blood.
Blood test - When your muscle has been damaged, as in a heart attack, your body releases substances in your blood. Blood tests can measure the substances and show if, and how much of, your heart muscle has been damaged. Blood tests are also done to measure the level of other substances in your blood, such as blood fats (e.g. cholesterol and triglycerides), vitamins and minerals.
