Cardiovascluar system

Question 1

Aorta:

Answer 1

The large trunk artery that carries blood from the left ventricle of the heart to branch arteries

Question 2

Aortic Semilunar Valve:

Answer 2

The valve that leaves or exits the left ventricle opening/entering the aorta

Question 3

Arterioles:

Answer 3

Small vessels that receive blood from the arteries

Question 4

Artery:

Answer 4

A blood vessel that carries blood from the heart to the body

Question 5

Atrium:

Answer 5

upper chamber of the heart that receives and holds blood that is about to enter the ventricle

Question 6

Coronary Arteries:

Answer 6

blood vessels that branch from the aorta and carry oxygen-rich blood to the heart muscle

Question 7

Pulmonary Artery:

Answer 7

one of two arteries (branches of the pulmonary trunk) that carry venous blood from the heart to the lungs

Question 8

Pulmonary Semilunar Valve:

Answer 8

heart valve opening from the right ventricle to the pulmonary artery

Question 9

Pulmonary Vein:

Answer 9

any of four veins that carry arterial blood from the lungs to the left atrium of the heart

Question 10

Valves:

Answer 10

flaps of tissue that open and close to allow the flow of blood in one direction only. The heart’s valves are located at the entrances and exits of its chambers

Question 11

Veins:

Answer 11

blood vessels that carry blood back to the heart

Question 12

Ventricle:

Answer 12

a chamber of the heart that receives blood from an atrium and pumps it to the arteries

Question 13

Venules:

Answer 13

small vessels that gather blood from the capillaries into the veins

Question 14

Capillaries:

Answer 14

tiny, thin-walled blood vessels that allow the exchange of gases and nutrients between the blood and the cells of the body

Question 15

Arteries 3 layers:

Answer 15

• Inner: Tunica intima, has a layer of flat cells, minimise friction with moving blood.
• Middle: Tunica media, has smooth muscle, collagen and elastic fibres.
• Outer: Tunica externa, has elastic fibres and collagen fibers

Question 16

Heart:

Answer 16

cardiac muscle.

Question 17

Atrial systole:

Answer 17

Both atria contract.
Blood fows from the atria into the ventricles. Backfow of blood into
the veins is prevented by closure of the valves in the veins.

Question 18

Ventricular systole:

Answer 18

Both ventricles contract.
The atrioventricular valves are pushed shut
by the pressurised blood in the ventricles. The semilunar valves in the aorta and pulmonary artery are pushed open. Blood fows from the ventricles into the arteries

Question 19

Ventricular diastole:

Answer 19

Atria and ventricles relax. The semilunar valves in the aorta and pulmonary artery are pushed shut. Blood fows from the veins through the atria and into the ventricles.

Question 20

R.b.c:

Answer 20

• Colour from haemoglobin, which main function is to transport O from lungs to respiring tissue.
• First r.b.c. formed in liver, then b.m.
• Short-lived

Question 21

Structure of r.b.c.:

Answer 21

• Shaped like a biconcave disc. Dents increase s.a. O can diffuse quicker.
• They are very small. D ~ 7um.
• They are very flexible. Deform to pass through smaller vessels.
• Have no nucleus, mitochondria or e.r. Lack of these make room for haemoglobin, maximising amount of O carried by each r.b.c.

Question 22

W.b.c.:

Answer 22

• Made in b.m.
• concerned with fighting disease.
• Phagocytes: destroys invading microorg by p.cytosis.
• Lymphocytes: Also destroys microorg. But not by p.cytosis. Some secrete a.b.’s, which attach and destroy the invading cells. Smaller than p.c.

Question 23

Structure of W.b.c.:

Answer 23

• Have nucleus.
• Larger than r.b.c.
• Either spherical or irregular shape. Never looking like a biconcave disc.

Question 24

Haemoglobin:

Answer 24

• Protein that Transport O from gas exchange surfaces of alveoli in the lungs to tossiges all over the body.
• It transports O around body inside r.b.c.
• Each h. m. is made up of four polypeptides, each containrar one haem group. Each haem group can combins with one O m. Overall then, Each h. m. can combins with four O m. (eight O atoms.)
• Hb + 4O2 <=> HbO8
  (Haemoglobin + Oxygen <=> Oxyhaemoglobin)

Question 25

Blood:

Answer 25

- Cells floating in plasma.

Question 26

Tissue fluid:

Answer 26

- Plasma leaks out between cells = t.f. | - Is like plasma but has less protein and no r.b.c. cause they are to big to go through endothelium. But some w.b.c. do.

Question 27

Plasma:

Answer 27

- Plasma is mostly water and some other subs. dissolved in it. (Nutrients, glucose, waste products and urea.) - Always flow through capillaries.