Chapter 8- Transport in animals

Question 1

What is the need for specialised transport systems in animals?

Answer 1

metabolic demand is high
small SA:V ratio
hormones needed may be made in one place and needed in another
food is digested in one organ system and needed in another
waste products need to be removed from cells and taken to excretory systems

Question 2

What is an open circulatory system:?

Answer 2

Blood is pumped from the heart straight into the body cavity
In haemocel, transport medium is under low pressure
Blood comes into direct contact with the cells
Transport medium returns directly to the heart through an open ended vessel

Question 3

What is haemolymph?

Answer 3

Doesnt carry O2 or CO2

Transports food and nitrogenous waste products to cells involved in fighting against disease

Question 4

What is a single closed circulatory system?

Answer 4

Continuous cycle of blood flow through the heart and body
Blood pumps through two sets of capillaries before returning to the heart
set 1- where O2 and CO2 are exchanged
set 2- substances from different organ systems are exchanged
blood returns to the heart slowly

Question 5

What is a double closed circulatory system?

Answer 5

Happens in active land mammals that maintain their own temperature
1st circulation- Blood is pumped from the heart to the lungs to pick up oxygen and unload CO2
2nd circulation- through the heart all around the body and back to the heart
has high blood pressure and blood flow

Question 6

What are the main components of blood vessels and their functions?

Answer 6

Elastic fibres- made of elastin, can stretch and recoil
Smooth muscle- contracts and relaxes, changes size of lumen
Collagen- provides structure, maintains shape and volume

Question 7

What are arteries?

Answer 7

They carry oxygenated blood away from the heart

High blood pressure

Question 8

What are the two arteries that do not carry blood away from the heart?

Answer 8

Pulmonary artery- carries deoxygenated blood away from the heart to the lungs
Pregnancy umbilical artery- carries blood from foetus to placenta

Question 9

What are arterioles?

Answer 9

Link arteries and capillaries
More smooth muscle than elastin
Can contract or dilate to control blood flow

Question 10

What is vasoconstriction?

Answer 10

When smooth muscle contracts, it constricts blood flow

Question 11

What is vasodilation?

Answer 11

When smooth muscle relaxes, it increases the blood flow into the capillaries

Question 12

What are capillaries?

Answer 12

Link arterioles with venules
RBCs flow through in single file
Blood has less O2 and more CO2 once it leaves them

Question 13

What are capillary adaptions?

Answer 13

Walls are 1 endothelial cell thick
Large SA for diffusion of substances
Total cross section area is always greater than the arteriole supplying it

Question 14

What are the 4 main functions of blood?

Answer 14

Transports oxygen to and carbon dioxide from respiring cells
Transports digested food from small intestine
Transports nitrogenous waste products to excretory organs
Transports hormones, food molecules, platelets, cells and antibodies

Question 15

What are the steps for tissue fluid formation?

Answer 15

1. Hydrostatic pressure is high and forces O2 , glucose and other substances through fenestrations
2. This forms the tissue fluid which bathes the body cells
3. Substances in the tissue are able to diffuse into the body cells
4. Plasma proteins are too big to fit through the fenestrations, however, lymph capillaries have larger pores and closed ends
5. Plasma proteins are taken into the lymphatic system which drains excess fluids, removes debris from the body cells and transports fats
6. Liquid in the lymphatic system is moved by compressions from body movements.
7. Lymph re-enters the blood system via veins located close to the heart.

Question 16

What is the average mass of the mammalian heart?

Answer 16

300g

Question 17

What is the pericardium?

Answer 17

Tough fibrous sac that protects the heart in the chest cavity

Question 18

What are the top two chambers of the heart called?

Answer 18

Atria

Question 19

What are the bottom two chambers of the heart called?

Answer 19

Ventricles

Question 20

What is the part of the septum that separates the atria?

Answer 20

Interatrial septum

Question 21

What part of the septum that separates the ventricles?

Answer 21

Interventricular septum

Question 22

What is the importance valves?

Answer 22

Prevents backflow

Maintain correct pressure of blood in heart chambers

Question 23

Why is the heart myogenic?

Answer 23

It can control its own contractions and relaxations without impulses from the central nervous system

Question 24

What does the SAN do?

Answer 24

Like a pacemaker
In wall of right atrium
Sets hearts rhythm by sending out regular electrical waves
Causes left and right atria to contract simultaneously

Question 25

What is the AVN?

Answer 25

Passes electrical waves onto bundle of HIS

Question 26

What is the bundle of His?

Answer 26

Group of muscle fibres which connect to the purplyne tissue

Question 27

What is the purplyne tissue?

Answer 27

Carries electrical waves into left and right muscle enabling it to contract simultaneously

Question 28

What does the height of the peak mean on an ECG?

Answer 28

Indicates amount of electrical charge of heart beat and the strength of the contraction

Question 29

What are the four main types of ECG?

Answer 29

Tachycardia- over 100 bpm
Bradycardia- under 60 bpm
Ectopic- extra heartbeat that is out of rhythm
Atrial fibrillation- example of arrhythmia

Question 30

What are the adaptions of erythrocytes?

Answer 30

Biconcave shape
Increased SA- effective diffusion
Small and flexible
No nucleus- more room for gases
Made in bone marrow 
Packed with haemoglobin

Question 31

What is haemoglobin?

Answer 31

Made by a 4 peptide chain that has an iron containing haem prosthetic group- tightly bound
Holds 4 oxygens

Question 32

What is oxyhaemoglobin?

Answer 32

When oxygen binds losely to haemoglobin

Question 33

What are the 3 main ways of transporting CO2 in the body?

Answer 33

5% carried in plasma
10-20% carried with AA group in polypeptide chain of Hb to form carbaminohaemoglobin
75-85% converted into hydrogen carbonate ions in RBC cyptoplasm

Question 34

What are the 2 main vessels that carry blood into the heart?

Answer 34

Inferior vena cava- carries blood from lower body

Superior vena cava- carries blood from head and upper body