Blood vessels and blood pressure

1. Blood Vessels and Blood Pressure
Naomi Okolo
Anatomy & Physiology IBSC1086-L
11/6/21

2. Blood Vessels and Blood Pressure
Blood vessels are tubular structures in the body
that facilitate blood circulation as blood flows
through them.
They form a network of structures comprising of
arteries, veins, capillaries, arterioles and venules.
The main blood vessels are arteries and veins.

3. Arteries
• They are vessels that carry blood enriched
with oxygen from the heart to the body
tissues.
• They are lined with smooth tissues with three
layers; intima lined with endothelium, media
that handles pressure from the heart and
adventitia attaching arteries to nearby
tissues..

4. Cont..
• The main artery is the aorta, which branches
into arterioles and capillaries.
• Pulmonary artery is the only artery that
carries de-oxygenated blood under low
pressure from the lungs to the heart for
oxygenation.

5. Veins
• These are tubular structures in the circulatory
system that carry blood depleted of oxygen
from the body vessels towards the heart.
• They act are returning messengers of
deoxygenated blood from the body organs to
the heart.
• Venules are smaller blood vessels in the
circulatory system that allow blood from
capillary beds to the veins.

6. Cont…
• Venules act as connectors of capillaries and
veins.
• Veins carry blood under low pressure.
• Vena cava is the major vain that drains the
upper body parts to the right atrium of the
heart.

7. Blood pressure
• Blood pressure refers to the force with which the
blood pushes itself against the walls of the arteries.
• The blood pressure is the highest when the heart
beats faster. This is as a result of increased contraction
and expansion of the heart muscles resulting to faster
blood pumping.

8. Cont…
• A place around the upper arm is cuffed and
inflated with a pump until circulation is cut off,
this is done using a stethoscope.
• Normal blood pressure is less than 120/80
mmHg.

9. Hypertension
• This is a condition accompanied by consistently
raised blood pressure that persists.
• Some of the causes are smoking, obesity, stress, high
alcohol consumption, older age, increased salt
intake, inactivity and genetic make up.
• symptoms include nose bleeding, severe headaches,
irregular heartbeat, blood in urine, difficulty
breathing and chest pain.

10. Shock
• This is a condition predisposed by a sudden
drop in blood pressure.
• It is caused by either trauma, heatstroke,
blood loss, allergy, severe burns, severe
infection or poisoning.
• This causes acute blood supply to the body
organs resulting in malfunctioning.
• Some of the symptoms include rapid
heartbeat, difficulty breathing, thirst and dry
mouth, shallow breath and low urine output.

11. Questions
1. What are blood vessels?
2. Name two major blood vessels.
3. What is a vein?
4. What are the functions of veins?
5. Which is the main vein and what does it do?
6. What is an artery?
7. What is the main artery and what is its function?
8. Define blood pressure and how it is measured.
9. Define hypertension and state its main causes.
10.Define shock and state its main causes.

12. References
• Monahan-Earley, R.; Dvorak, A. M.; Aird, W. C.
(2013). "Evolutionary origins of the blood vascular
system and endothelium". Journal of Thrombosis and
Haemostasis.
• Pratt, Rebecca. "Cardiovascular System:
Blood". AnatomyOne. Amirsys, Inc.
• Sherwood, Lauralee (2011). Human Physiology: From
Cells to Systems. Cengage Learning.

13. Answer key
1. Blood vessels are tubular structures in the circulatory system that
facilitate blood flow.
2. Arteries and veins
3. A blood vessel that transports oxygen depleted blood from the body
parts to the heart except pulmonary vein which carries oxygenated
blood.
4. Carrying deoxygenated blood from the body organs to the heart
except pulmonary vein.
5. Vena cava. It carries blood to the heart from other body parts.
6. Blood that carries oxygenated blood from the heart to body parts
except pulmonary artery carrying deoxygenated blood.
7. Aorta – carry oxygenated blood from left ventricle to other body
parts.
8. Blood pressure is the pressure of blood within the blood vessels. It
is measured using a stethoscope.
9. Hypertension is a condition when the blood pressure is persistently
high. It can be caused by smoking, obesity, stress, high alcohol
consumption among others
10. Shock is a condition predisposed by a sudden drop in blood
pressure. It is caused by trauma, allergy, blood loss among others.