9: Transport in animals

Question 1

What is circulatory system?

Answer 1

a system of blood vessels with a pump and valves to ensure one-way flow of blood

Question 2

Describe the single circulation of a fish

Answer 2

Fish

• two heart chambers
• per circuit blood goes through heart once

heart ➝ gills ➝ body = repeat

Question 3

Describe the double circulation of a mammal

Explain its advantages

Answer 3

Mammals
- four heart chambers
- per circuit blood goes through heart TWICE
heart ➝ lungs ➝ heart ➝ body

Why?
Mammals have greater need for oxygen to use in respiration for warmth
- can maintain high blood pressure = increase the speed in nutrient delivery + waste removed = more efficient

Question 4

Describe the blood flow

Answer 4

Right side of heart (technically left)
- deoxygenated blood enters vena cava, right atrium, AV/ tricuspid valve, right ventricle, semilunar valve, pulmonary artery, lungs

Left (technically right)
- pulmonary vein, left atrium, AV/ bicuspid valve, left ventricle, semilunar valve, aorta (artery) = body, vena cava

Question 5

What is a septum? Why is it important?

Answer 5

Separates 2 sides of the heart,

prevents the mixing of deoxygenated and oxygenated blood

Question 6

Describe relative thickness of the muscle wall of left and right ventricle

Answer 6

Right - lungs

Left ventricle - pumps blood around the body - further distance = blood under higher PRESSURE

Question 7

Describe relative thickness of the muscle wall of atria compared to ventricles

Answer 7

Ventricles pump blood around the body/ lungs = need to withstand higher pressure
Atria - only to ventricles = lower pressure

Question 8

What tissue is the heart made of?

Answer 8

cardiac muscle

Question 9

What is the function of coronary artery?

Answer 9

supplies heart muscle with blood

Question 10

Describe coronary heart disease: why does it happen?

Answer 10

blockage of coronary arteries

by buildup of cholesterol ➝ limiting blood flow to heart

Question 11

How to measure heart’s activity?

Answer 11

Electrocardiogram - ECG
pulse rate
valve activity - listening to sounds of valves closing

Question 12

What are risk factors of coronary heart disease (6)

how to prevent

Answer 12

smoking, diet, stress, genetic predisposition, age, gender

exercise regularly control diet - less saturated fats, fruit, veg
no smoking, drinking

Question 13

Treatment of coronary heart disease

Answer 13

Drug treatment - ASPIRIN (thins blood, platelets less likely to clump)
Surgery - stent, angioplasty, bypass

Question 14

Effect of physical exercise on the heart rate [4]

Answer 14

heart rate increases
short term: muscles respire to produce energy
aerobic respiration requires oxygen = heart rate increases = blood pumped quicker = more oxygen is delivered to respiring tissues

• adrenaline stimulates increase in heart/pulse rate
• increase of carbon dioxide concentration in blood
• nerves stimulate heart to beat faster
• muscles require more energy, so rate of aerobic respiration increases
• increase demand for oxygen/glucose; quicker removal of CO2 /lactic acid
• more blood to lungs per unit time is needed
• more blood/oxygen/glucose to muscles

(pulse rate is exactly equal to the heart rate, as the contractions of the heart cause the increases in blood pressure in the arteries that lead to a noticeable pulse)

Question 15

Valves

Answer 15

prevent back flow of blood

Question 16

all vessels

Answer 16

[HEART] ➝ artery ➝ arteriole ➝ capillary ➝ venule ➝ vein ➝ [HEART]
shunt vessel

Question 17

veins structure and function; how are they adapted to them

what do they brunch into?

Answer 17

• carry DEOXYGENATED blood at LOW pressure TOWARDS the heart

a: large lumen - low blood pressure = no need to control it
contain valves - low blood pressure = prevent backflow

branch into VENULES

thin/ less elastic / less muscular walls (than arteries) = low blood pressure, allows vein to be squeezed by (surrounding skeletal) muscles ;

Question 18

Function of arterioles

why must blood pressure decrease in the arterioles before entering capillaries? [2]

Answer 18

distribute blood flow into capillary beds

high pressure would burst capillaries
capillary walls are thin/ narrow
wall/ lining, (of capillary) is one cell thick

Question 19

venules

Answer 19

small veins which are formed by groups of capillary vessels

Question 20

capillaries structure and function; how are they adapted to them
what do they brunch into? 5

Answer 20

carry BOTH oxygenated and deoxygenated blood

a:low pressure - used to exchange substances with tissues
large SA, branched
small diameter, lumen - to decrease diffusion distance
walls one cell thick - substances can diffuse in&out
slow rate of blood flow - to allow time for exchange

Question 21

describe the ‘leaky’ walls of capillaries :D

Answer 21

blood plasma can leak out - form tissue fluid surrounding cells

Question 22

Shunt vessels function

Answer 22

change size to control amount of blood flowing to certain area: dilate or constrict

Question 23

Main blood vessels to and from: heart, lungs and kidney, liver

Answer 23

towards ➝ away
Heart: vena cava, pulmonary vein ➝ pulmonary artery, aorta

Lungs: pulmonary artery ➝ pulmonary vein

Kidney: renal artery ➝ renal vein

Liver hepatic artery, hepatic portal vein ➝ hepatic vein

Question 24

What is lymphatic system

Answer 24

system of vessels and lymph nodes that are involved in returning tissue fluid to blood and in immunity

Question 25

Explain the process of lymphatic system

Answer 25

- CAPILLARIES exchange substances with cells by producing TISSUE FLUID at ARTERIOLE end - high pressure in narrower blood vessel forces out nutrients/plasma into tissue fluid - nutrients diffuse into cells; waste + large molecules into tissue fluid at venous end - carried away by lymph system enter/exit lymph vessels ➝ travel as lymph fluid ➝ drain into blood system in chest cavity

Question 26

``` What are lymph nodes? function what do they contain? ```

Answer 26

small clusters of lymphatic tissue found in lymphatic system (vessels), neck, armpits, groin - filter lymph fluid - removing bacteria, foreign particles = protect body from infection - contain lymphocytes

Question 27

What does blood contain?

Answer 27

red blood cells, white blood cells, platelets, plasma (55%)

Question 28

Function of platelets

Answer 28

involved in blood clotting

Question 29

Describe the process of blood clotting | its role

Answer 29

- occurs when blood vessel breaks (injury) - prevents BLOOD LOSS and ENTRY OF PATHOGENS 1. Platelets stick to broken vessel, clump together, blocking the cut 2. Platelets release soluble FIBRINOGEN proteins ➝ converted into FIBRIN ➝ FORMS A MESH of fibrin fibres process of clotting as the conversion of fibrinogen to fibrin to form a mesh

Question 30

plasma function

Answer 30

transport of blood cells, ions, soluble nutrients, hormones and carbon dioxide

Question 31

Red blood cell

Answer 31

``` transporting oxygen contains haemoglobin (protein) which binds to oxygen allowing it to be transported ``` biconcave shape, enucleate, oxygen is in form of oxyhaemoglobin

Question 32

white blood cells function | what are two types

Answer 32

phagocytosis and antibody production defends against infection (part of immune system) - lymphocytes and phagocytes LYMPHOCYTES (type of wbc) produce ANTIBODIES to - destroy PATHOGENS and - ANTITOXINS - to neutralise toxins released by pathogens

Question 33

function of antibody production

Answer 33

each antibody is specific to 1 type of antigen - White blood cells detect pathogen - specific ANTIBODIES (produced by lymphocytes) bind to - specific and complementary ANTIGEN (protein found on cell membrane of pathogens) - antibody-antigen complex is formed

Question 34

phagocytes function | Describe the process of phagocytosis (3)

Answer 34

carry out phagocytosis by engulfing and digesting pathogens Phagocytosis: 1. Phagocyte recognises, attaches to foreign pathogen 2. membrane of phagocyte ENVELOPS the pathogen, folds forward, trapping it inside the phagocyte 3. phagocyte RELEASES ENZYMES which break down pathogen, killing it.

Question 35

describe one named example of surgery that can treat coronary heart disease. [2]

Answer 35

stent - small mesh tube inserted in artery; opens / supports narrow artery balloon angioplasty - catheter with balloon inserted into artery inflate balloon to widen artery ; by-pass - shunt blood vessel joined/replace artery