Blood vessels and heart

Question 1

Name the Blood vessels entering and leaving heart

Answer 1

Aorta
vena cava
Pulmonary artery and pulmonary veins

Question 2

Aorta

Answer 2

takes oxygenated blood from heart to respiring tissues

Question 3

vena cava

Answer 3

takes deoxygenated blood from respiring tissues → heart

Question 4

Name the Blood vessels entering and leaving lungs

Answer 4

Pulmonary vein
Pulmonary artery

Question 5

Pulmonary artery

Answer 5

takes deoxygenated blood from the heart → lungs

Question 6

Pulmonary vein

Answer 6

takes oxygenated blood from the lungs →heart

Question 7

Name the Blood vessels entering and leaving kidneys

Answer 7

Renal artery
Renal vein

Question 8

Renal arteries

Answer 8

take oxygenated blood → kidneys

Question 9

Renal veins

Answer 9

take deoxygenated blood to the vena cava from the kidneys

Question 10

Describe the pathway blood takes in a closed double circulatory system.

Answer 10

Closed double circulatory system-two circuits

Blood passes through heart twice for
each complete circulation of body

Pulmonary circulation
Deoxygenated blood in right side of heart pumped to lungs →oxygenated blood returns to left side of heart

Systemic circulation
Oxygenated blood in left side of heart pumped to tissues / organs of body→ deoxygenated blood returns to right side

Question 11

Explain the importance of mammals having a closed double
circulatory system.

Answer 11

Prevents mixing of oxygenated and deoxygenated blood → so blood
pumped to body is fully saturated with oxygen → efficient delivery of
oxygen and glucose for respiration

Blood can be pumped at a higher pressure (after being lower from lings)→ substances taken to and removed from body cells quicker and more efficiently

Question 12

Structure of the heart

Answer 12

Atrioventricular valves
semi- lunar valves
thick muscular walls on left
Thin muscular walls on right

Question 13

Atrioventricular valves

Answer 13

Prevent backflow of blood from ventricles to atria

Question 14

Semi lunar valves

Answer 14

Prevent backflow of blood from arteries to ventricles

Question 15

Left has a thicker muscular wall

Answer 15

• Generates higher blood pressure
• For oxygenated blood has to travel greater distance around the body

Question 16

Right has thinner muscular walls

Answer 16

• Generates lower blood pressure
• For deoxygenated blood to travel a small distance to the lungs where high pressure
  would damage alveoli

Question 17

Structure of arteries

Answer 17

Thick smooth muscle layer
Elastic tissue layer
Thick wall
Smooth endothelium
Narrow lumen

use acronym TENTS

Question 18

Thick smooth muscle layer

Answer 18

-Contract pushing blood along; maintain blood pressure

Question 19

Elastic tissue layer

Answer 19

Allows for recoiling to reduce pressure surges and maintain high blood pressure

Question 20

Thick wall

Answer 20

• Withstands high pressure and prevents artery bursting

Question 21

Smooth endothelium

Answer 21

Reduces friction

Question 22

Narrow lumen

Answer 22

Increases and maintains high blood pressure

Question 23

Structure of veins

Answer 23

Wider lumen than arteries
Very little elastic and muscle tissue
Valves=Prevent backflow of blood
Contraction of skeletal muscles squeezes veins, maintaining blood flow

Question 24

capillaries

Answer 24

allow the efficient exchange of gases and nutrients between blood and tissue fluid

Question 25

structure of capillaries

Answer 25

-walls-thin layer of squamous and endothelial cells---> short diffusion pathway= rapid diffusion -Capillary beds-large network of capillaries-------> increase SA=rapid diffusion -Narrow lumen-Reduces flow rate so more time for diffusion -Capillaries permeate tissues=Short diffusion pathway -Pores in walls between cells =Allows substances to escape e.g. white blood cells to deal with infections

Question 25

what is tissue fluid and whats its purpose

Answer 25

Provides respiring cells with e.g. water / oxygen / glucose / amino acids. Enables (waste) substances to move back into the blood e.g. urea, lactic acid, carbon dioxide

Question 26

The formation of tissue fluid (arteriole end)

Answer 26

Higher hydrostatic pressure inside capillaries (due to contraction of left ventricle) than tissue fluid Forces fluid / water out of capillaries Large plasma proteins remain in capillary (too large to leave capillaries)

Question 27

The return of tissue fluid to the circulatory system (venule end)

Answer 27

Hydrostatic pressure reduces as fluid leaves capillary. (Due to water loss,) an increasing concentration of plasma proteins lowers the water potential in the capillary below the water potential of the tissue fluid Water (re-)enters the capillaries from the tissue fluid by osmosis down a water potential gradient Excess water taken up by lymph system and is returned to the circulatory system

Question 28

Suggest a reason why tissue fluid could accumulate in a certain area.

Answer 28

Low concentration of protein in blood plasma can lead to an accumulation of tissue fluid: - Water potential in capillary not as low so water potential gradient is reduced - More tissue fluid formed at arteriole end - Less / no water absorbed into blood capillary by osmosis High blood pressure can lead to an accumulation of tissue fluid: -High blood pressure = high hydrostatic pressure - Increases outward pressure from arterial end of capillary - So more tissue fluid formed - And the lymph system is not able to drain tissues fast enough

Question 29

Atrial systole

Answer 29

-Atria contract → decreasing volume and increasing pressure inside atria -Atrioventricular valves forced open -When pressure inside atria > pressure inside ventricles, atrioventricular valves open -Blood pushed into ventricle

Question 30

Ventricular systole

Answer 30

-Ventricles contract from the bottom up → decreasing volume and increasing pressure inside ventricles -Semilunar valves forced open -When pressure inside ventricles > pressure inside arteries -Atrioventricular valves shut -When pressure inside ventricles > pressure inside atria -Blood pushed out of heart through arteries

Question 31

Diastole

Answer 31

Atria and ventricles relax → increasing volume and decreasing pressure inside chambers Blood from veins fills atria (increasing pressure inside atria slightly) and flows passively to ventricles Atrioventricular valves open When pressure inside atria > pressure inside ventricles blood flows passively to ventricles Semilunar valves shut When pressure inside arteries > pressure inside ventricles

Question 32

Give the equation that links heart rate, cardiac output and stroke volume.

Answer 32

Cardiac output = stroke volume x heart rate

Question 33

What is meant by the terms heart rate, cardiac output and stroke volume?

Answer 33

Cardiac output = amount of blood pumped out of the heart per minute Stroke volume = volume of blood pumped by the ventricles in each heart beat Heart rate = number of beats per minute

Question 34

Describe how an atheroma can result in a heart attack

Answer 34

Atheroma causes narrowing of coronary arteries Restricts blood flow to heart muscle supplying glucose, oxygen etc. Heart anaerobically respires → less ATP produced → not enough energy for heart to contract → lactate produced → damages heart tissue / muscle

Question 35

Give some risk factors for cardiovascular heart disease

Answer 35

Age Diet high in salt or saturated fat High consumption of alcohol Stressful lifestyle Smoking cigarettes Genetic factors

Question 36

What factors should be considered when evaluating study design?

Answer 36

Small sample size Take into account other risk factors (variable) that could have affected results Used similar groups e.g. age, gender Way in which info collected e.g. questionnaires may be unreliable as people lie or give inaccurate information Results reproduced by other scientist by carrying out more studies and collecting more results