Circulatory System

Question 1

Atria(Atrium)

Answer 1

reservoirs where blood collects from veins

Question 2

Ventricles

Answer 2

Pump blood out of the heart at high pressures into the arteries

Question 3

Inferior/Superior Vena Cava

Answer 3

large veins that pump deoxygenated blood into the right atrium

Question 4

Do all of the arteries of the body carry oxygenated blood?

Answer 4

No, the pulmonary artery carries deoxygenated blood from the heart to the lungs.

Question 5

Goals of the circulatory system

Answer 5

Distribution of nutrients, oxygen, metabolic waste products, hormones and homeostasis

Question 6

Perfusion

Answer 6

Flow of blood through a tissue

Question 7

Arteries

Answer 7

Vessels that carry blood away from the heart at high pressure

Question 8

Veins

Answer 8

Vessels that carry blood toward the heart at low pressure

Question 9

Arterioles

Answer 9

Increasingly smaller branches from arteries as the pressure of blood flow starts to decreases

Question 10

Ischemia

Answer 10

inadequate blood flow

Question 11

Hypoxia

Answer 11

Reduced supply of oxygen

Question 12

What’s the difference between ischemia and hypoxia?

Answer 12

In hypoxia, wastes are adequately removed, but in ischemia they build up. Ischemia is worse.

Question 13

If the arterioles constrict in a tissue, will material diffuse through the wall of the arterioles into the tissue?

Answer 13

No, all exchange of material between the blood and tissues must occur in capillaries. The walls of arterioles are too thick and muscular for exchange to occur.

Question 14

Capillaries

Answer 14

Very small vessels where only a single/ few blood cells from the arterioles pass through and where exchange occurs between blood and tissues

Question 15

Aorta

Answer 15

Single large artery where blood is pumped from the left ventricle

Question 16

Inner lining of all blood vessels is formed by a thin layer of

Answer 16

Endothelial cells

Question 17

Functions of endothelial cells

Answer 17

Vasodilation and vasoconstriction, inflammation, angiogenesis, thrombosis

Question 18

Two main types of circulation of blood

Answer 18

Pulmonary (heart to lungs) and systemic circulation (heart to rest of the body)

Question 19

Why have mammals evolved a separate circulation for the lungs in comparison to, for example fish?

Answer 19

Mammals need more pressure to reach both the body and lungs, so having two separate circulations solves this problem

Question 20

Hepatic portal system

Answer 20

Blood passes through capillaries in the intestine > collects in veins to travel to the liver > blood once again passes through capillaries

Question 21

Hypothalamic-hypophysial portal system

Answer 21

Blood passes through the capillaries in the hypothalamus > portal veins > capillaries in the pituitary gland

Question 22

What are portal systems and why did the evolve?

Answer 22

They are direct transport systems where nutrients can be directly passed from the intestine to the liver or hypothalamus to the pituitary without passing through the whole body

Question 23

Coronary arteries

Answer 23

Branches from the aorta which supply blood to the wall of the heart

Question 24

“Coronary”

Answer 24

encircle the heart

Question 25

Coronary veins

Answer 25

Deoxygenated blood from the heart travels through this and combine to form the coronary sinus (directly drains into the right atrium)

Question 26

The two atrioventricular valves are

Answer 26

Bicuspid valve (between the left atrium and left ventricle) and the tricuspid valve (between the right atrium and right ventricle)

Question 27

the two semilunar valves

Answer 27

The pulmonary (between right ventricle and pulmonary artery) and aortic semilunar valve (between left ventricle and the aorta)

Question 28

How does blood in veins travel back to the heart when there is low pressure?

Answer 28

Contraction of skeletal muscles and the venous valves which prevent back flow

Question 29

What is the result of venous valve failure?

Answer 29

Varicose veins - veins where venous pressure increases in the legs

Question 30

Diastole

Answer 30

Relaxation of ventricles of ventricles and contraction of atriums to propel the blood into the ventricles

Question 31

Systole

Answer 31

Contraction of ventricles and closing of AV valves to increase the pressure in the ventricles to ultimately open the semilunar valves; when the ventricle is nearly empty, there is less pressure so the semilunar valves close

Question 32

How strong is atrial compared to ventricular contraction?

Answer 32

Much weaker, the muscular walls of atria are much thinner, the ventricles need more muscle to pump blood into capillaries throughout the body

Question 33

Cardiac output equation

Answer 33

CO = SV * HR Cardiac output (L/min) = Stroke volume (L/beat) x Heart rate (beats/minute)

Question 34

Is diastole or systole longer?

Answer 34

Diastole, as it is the time between the lub-dup