AN120: CVS

Question 1

What is the Cardiovascular system?

Answer 1

• AKA circulatory system because the blood vessels and heart form a closed circle.
• the flow of blood begin in one point (heart) and move to all the body parts and return back to the same point; heart.

Question 2

What is the path in CVS?

Answer 2

heart to artery to small arteries to arterioles (smallest arteries) to capillaries to venules (smallest veins) to small veins to veins to heart.

Question 3

What is the CVS made of?

Answer 3

1. muscular pump: heart
2. branching network of tubes: blood vessels
3. a liquid: blood

Question 4

What is the heart?

Answer 4

• viscera (internal organ)
• its cavity is divided into 4 chambers & the wall is formed of muscular tissue; cardiac muscles.

Question 5

What are the upper 2 chambers of the heart?

Answer 5

They are the atria (atrium for one)
- right & left
- separated by interatrial septum

Question 6

What are the lower two chambers of the heart?

Answer 6

ventricles, rt & lt
- separated by interventricular septum

Question 7

What is the path of blood in the heart?

Answer 7

A vein would pour into the atrium where the blood in the atrium pours into the ventricle that pours into the artery. The only “junction” lacking a valve is the one between the vein & atrium; the rest contain a valve.

Question 8

What are the 4 great blood vessels connecting to the heart chambers?

Answer 8

1. Aorta
2. Superior Vena Cava
3. Pulmonary arteries
4. Pulmonary veins

Question 9

What is the aorta?

Answer 9

• biggest artery in the body
• carries blood from left ventricle to all body parts & all organs but the lungs.

Question 10

What does the superior vena cava do?

Answer 10

returns blood from upper part of the body (head, neck, both upper limbs, & wall of the chest)

Question 11

What does the inferior vena cava do?

Answer 11

returns blood from lower part of the body (abdomen & lower limbs) to the right atrium.

Question 12

What do the pulmonary arteries do?

Answer 12

carry blood from right ventricle to the lungs

Question 13

What do the pulmonary veins do?

Answer 13

return blood from the lungs to the left atrium.

Question 14

What are the features of the atria?

Answer 14

• small
• thin walls
• function as a temporary resevoir for blood before pumping into ventricles

Question 15

What are the features of the ventricles?

Answer 15

• larger & thicker-walled than compared to atria.
• pumps blood into great vessels

Question 16

What is the pericardium

Answer 16

• double-layered, serous membrane, closed sac filled with a thin film of liquid known as pericardial fluid
• surrounds the heart
• allows free movement of the heart, i.e. to decrease the friction

Question 17

What are the two layers of the pericardium?

Answer 17

1. inner (visceral) layer: adherent to the heart.
2. outer (parietal) layer: covered by a fibrous tissue known as fibrous pericardium.

Question 18

What prevents overdistention (over-enlargement)?

Answer 18

The fibrous pericardium

Question 19

What are the 3 types of blood vessels?

Answer 19

1. arteries
2. veins
3. capillaries

Question 20

What are the 4 factors that determine the type of blood vessel?

Answer 20

according to:
1. direction of blood movement
2. type/state of blood
3. diametre of lumen & thickeness of wall
4. the pressure

Question 21

What are arteries?

Answer 21

Vessels that carry blood from the heart to organ tissues, i.e. away from the heart.

Question 22

What are characteristics of arteries?

Answer 22

• narrow lumen
• thick wall of smooth muscles/ elastic fibres to resist the high pressure
• all carry oxygenated blood rich in oxygen & nutrients to the tissue cells.

Question 23

What is the exception in arteries’ oxygenation?

Answer 23

Pulmonary trunk: it’s two branches carry deoxygenated blood

Question 24

What are veins?

Answer 24

vessels that carry blood from the capillaries toward the heart

Question 25

What are characteristics of veins?

Answer 25

- wide lumen - thinner walls; collapsed when empty - there is low blood pressure in the veous system (low venous pressure) - contains valves to allow blood flow toward heart only - all veins carry deoxygenated blood full of waste products/

Question 26

What is the exception for the veins?

Answer 26

Pulmonary veins, which return ell-oxygenated blood to the heart.

Question 27

What are the types of arteries?

Answer 27

1. elastic 2. muscular 3. arterioles

Question 28

What are the types of veins?

Answer 28

according to size, they are: 1. large veins 2. medium veins 3. venules

Question 29

What are small veins that unite to form large veins called?

Answer 29

Tributaries

Question 30

The largest type of artery

Answer 30

Elastic arteries, they are the largest and are formed of elastic tissue ex. aorta

Question 31

Medium-sized artery

Answer 31

Muscular artery. Their walls are formed of smooth muscles and distribute blood to various organs

Question 32

Examples of muscular artery

Answer 32

1. hepatic artery 2. renal artery 3. ulnar artery

Question 33

What are the arterioles

Answer 33

they are the smallest type of artery, with a narrow lumen and **thick** wall. - less that 0.1mm wide in diametre

Question 34

What is a feature of large veins? | with example of one

Answer 34

They have no valves - ex. vena cava

Question 35

What is an example of medium-sized veins

Answer 35

cephalic basilic - they have valves

Question 36

What are the smallest veins?

Answer 36

Venules - drain the capillaries & unite with each other to form larger veins that have no valves.

Question 37

What are capillaries

Answer 37

Small, thin vessels which form a network that connects arteries to veins.

Question 38

What are some characteristics of capillaries?

Answer 38

- small lumen and very thin wall - wall is only one layer of flat cells - arranged in network called capillary bed

Question 39

What is the function of cardiovascular system

Answer 39

1. transports and distributes oxygen and other nutrients to all cells of the body (blood rich in oxygen & other nutrients) 2. excretion of waste products through kidneys, liver, & lungs 3. control of body temperature 4. maintain the level of blood pressure within normal range 5. regulate blood flow to different organs according to activity

Question 40

How is blood pressure maintained?

Answer 40

by elastic recoil of aorta and vasoconstriction of arterioles

Question 41

How does venous blood return to heart? | non-pulmonary

Answer 41

venous blood from all over the body return to the Rt atrium by two large veins: sup. & inf. vena cava

Question 42

What is pulmonary circulation?

Answer 42

- movement of blood from heart to lung & from lung to the heart - inside the lung gas exchange takes place - oxygenated blood returns to the Lt atrium via pulmonary veins

Question 43

What is systemic circulation

Answer 43

flow of blood from the heart to the rest of the body and from the rest of the body to heart

Question 44

How does system circulation occur?

Answer 44

- oxygenated blood returns to the Lt atrium by pulmonary veins - left ventricle contracts to pump blood into aorta which distributes oxygenated blood to all parts of the body.

Question 45

What are anastomoses between large arteries?

Answer 45

They allow alternative pathways for blood if one from the main arteries is occluded. - can be found around the base of the brain and around major joints

Question 46

What is the end artery?

Answer 46

- There are no anatomical end artery (no anastomoses with adjacent arteries) such as segmental arteries of kidney and spleen - functional end artery in heart & brain, there is anastomoses which cannot maintain tissue survival when the main artery occludedd suddenly.

Question 47

What is the anastomoses between veins?

Answer 47

- blockage of veins rarely lead to tissue damage due to presence of network of alternative pathways - ex. intrathoracic azygos system

Question 48

What are arteriovenous anastomoses

Answer 48

Directly between small arteries & small veins in the alimentry tract and in the skin - rich in nerve supply and regulate the blood flow to various organs

Question 49

Clinical Nores

Answer 49

1. arterial pulse: radial artery, doralis pedis artery 2. tortuous arteries: facial, uterine, splenical artery 3. pelvic plexuses are a source of tumor metastases to vertebral column because they lack valves 4. elongation & dilation of superficial veins of the leg is known as varicose veins