3.1.2 Transport in Animals COMPLETE

Question 1

Features of an effective transport system

Answer 1

• Fluid to carry O2 and nutrients around the body i.e. blood
• A pump to create pressure that’ll push the fluid around the body
• Exchange Surfaces that enable oxygen and nutrients to enter and leave the blood.

Question 2

Closed Circulatory system

Answer 2

Blood enclosed in vessels all the time, called bleeding when its not. High pressure so is rapid, exchange surfaces are necessary.
Eg invertebrates/ mammals

Question 3

Open Circulatory system

Answer 3

Blood not in vessels and it just fills the body cavity, heart pumps blood form the arteries directly into the haemocoel, no gases are contained in the blood. Lower pressure so less rapid
e.g. insects

Question 4

Double circulatory system

Answer 4

Blood flows through the heart twice for each complete circuit of the body. Involves the pulmonary and systematic system. Moves rapidly due to the high pressure (Higher in the systematic as moving to rest of the body)

Question 5

Single circulatory system

Answer 5

Blood flows through the heart once for each complete circuit of the body. Pressure is reduced as blood passes through tiny capillaries or gills, therefore rate of waste removal is slower
e.g. fish

Question 6

Advantages of a double circulatory system

Answer 6

The blood doesn’t mix
A higher O2 conc leads to a steeper conc. gradient and faster diffusion.
Pressure can also be increased so blood flow to the tissues is much faster

Question 7

Order of Blood flow

Answer 7

Heart -> Arteries -> Arterioles -> Capillaries -> Venules -> Veins -> Heart

Question 8

Structure of Arteries

Answer 8

• High pressure blood
• Wall is thick to withstand pressure
• Narrow lumen to maintain pressure
• Inner wall folded to allow expansion
• Epithelium lines with squamous cells to make it smooth

Question 9

Structure of Arterioles

Answer 9

Same as arteries but with more smooth muscle and less elastin. This is to allow vasodilation and vasoconstriction

Question 10

Structure of Capillaries

Answer 10

• Very narrow (same as a RBC)
• Endothelium made of one layer of squamous cells
• Walls are porous to allow plasma and dissolved nutrients to leave the blood
• Form large networks to increase SA contact with tissues

Question 11

Structure of Veins

Answer 11

• Low pressure blood
• Larger lumen
• Surrounding muscles move the blood
• Contain valves that only open when moving towards the heart to prevent back flow

Question 12

Vessel layers

Answer 12

Inner Layer: Endothelium cells (reduce friction) and thin layer of elastin
Middle Layer: Smooth muscle (contracts to narrow lumen)
Outer Layer: Collagen and elastic tissue (stretch and recoil)

Question 13

Internal Features of the Heart

Answer 13

• Septum separates the two sides
• Atrioventricular valves
• Tendinous chords
• Aorta and Pulmonary Artery
• Vena Cava and Pulmonary Vein

Question 14

Atrioventricular Valves

Answer 14

Valves between the atria and ventricles
Tricuspid on the right
Bicuspid on the left
(drawings of the heart are in reverse)

Question 15

The two arteries

Answer 15

Aorta from the left ventricle to the body

Pulmonary Artery from the right ventricle to lungs

Question 16

The two veins

Answer 16

Vena Cava from the body to the left atrium

Pulmonary Vein from the lungs into the right atrium

Question 17

Myogenic Muscle

Answer 17

Cardiac muscle that automatically contracts and relaxes without any stimulation from nerves. Have their own natural frequency.

Question 18

How does the heart squeeze

Answer 18

Cardiac muscle consists of fibres that branch and produce cross bridges, these help spread the stimulus.
Intercalated disks help facilitate synchronised contraction

Question 19

Semi Lunar Valves

Answer 19

Found in the aorta and pulmonary artery, prevents back flow into them, high pressure in the ventricles forces them open

Question 20

Ventricular Septum

Answer 20

Separates the left and right ventricle, purkinje tissue is inside, stop the bloods from each chamber mixing

Question 21

Coronary Arteries

Answer 21

First blood vessels to branch of the aorta, extend across the heart to supply oxygenated blood to the heart muscle.

Question 22

Three phases of the Cardiac Cycle

Answer 22

1. Atrial Systole
2. Ventricular Systole
3. Diastole

Question 23

Atrial Systole

Answer 23

Muscle wall in the Atrial contracts, pressure created is limited due to the thin walls, but its enough to force blood into the ventricles through the AV valve. Valves prevent back backflow

Question 24

Ventricular Systole

Answer 24

Thick muscle walls in the ventricle squeezes inwards to increase pressure and push blood out of the heart. Once pressure is greater in the ventricle than the atria AV valves shut. Semilunar valves are then forced open.

Question 25

Diastole

Answer 25

Heart muscles relax, elastic tissue in the walls recoils to stretch out the muscle. Pressure drops and the semilunar valves shut. Atrial systole begins as blood flows back into the atria

Question 26

Fibrillation

Answer 26

When the frequency of contraction in the heart chambers is not properly coordinated leader to non synchronised contractions

Question 27

Atrial Contraction

Answer 27

Initiated by the Sino- Atrial Node which is a small patch pf muscle in the wall of the right atrium. Contracts slightly faster so spreads a wave of electrical activity over the atrial walls. They respond by contracting in the same rhythm as the SAN

Question 28

Ventricular Contraction

Answer 28

Collagen fibres between the Atria and Ventricles do not conduct the electrical wave. The only route is through the Atrioventricular Node. Electrical excitation is passed on to a bunch of connective tissue which runs down the septum (Purkinje tissue)
It rapidly travels to the apex and causes ventricles to contract upwards squeezing blood into the arteries

Question 29

What affects Heart rate

Answer 29

• Cardiovascular fitness
• Underlying Medical Conditions
• Drugs
• Exercise
• Age
• Fear/shock

Question 30

Electrocardiograms

Answer 30

The first small peak represents atrial systole P
The larger peak and small drop is ventricular systole QRS
The second smaller peak is ventricular diastole T

Question 31

Bradycardia

Answer 31

When the heart rate slows down, can be due to fitness or a more severe when a pacemaker is then needed

Question 32

Tachycardia

Answer 32

Heart beat is very rapid, normal during exercise or when scared, but if abnormal could be due to problems with eh electrical control in the heart and will need treatment

Question 33

Ectopic Heartbeat

Answer 33

Extra heartbeats that are out of the normal rhythm, serious when they’re frequent

Question 34

Atrial Fibrillation

Answer 34

No clear P wave, means there is an abnormal rhythm of the heart and rapid electrical pulses are generated in the atria

Question 35

What is blood

Answer 35

Cells floating in a yellow fluid called plasma, contains hormones, urea and proteins. RBC carry the O2
Platelets cause clotting
WBC are part of the immune response

Question 36

What is Tissue Fluid

Answer 36

Formed from the plasma that has leaked from capillary walls. very similar in composition to plasma but contains less proteins as they can’t pass through the capillary walls. Its essential for the exchange of materials i.e. CO2, Lactic acid

Question 37

What is Lymph

Answer 37

90% of leaked fluids from the capillaries are returned. The remaining 10% is collected in lymph vessels, these are tiny blind endings or termination points.
Similar to tissue fluid but less O2 more CO2

Question 38

Lymph Transportation

Answer 38

Its first transported to the subclavian veins, valves inside, pressure builds due to surrounding muscle contractions. Flow is slow through the thoracic duct. Lymphocytes are produced here and allow the filtering of bacteria and foreign particles.

Question 39

How are RBC adapted

Answer 39

Biconcave disks increases SA
No nucleus so more room for haemoglobin
Same size as capillary to shorten diffusion path
Contain lots of haemoglobin for O2

Question 40

Haemoglobin

Answer 40

A globular protein with 4 polypeptide chains each with a haem prosthetic group. Oxyhaemoglobin forms when a oxygen joins onto the Fe2+.
Reversible reaction, loading and unloading/ association and dissociation. Haem has an affinity for O2

Question 41

Oxygen affinity

Answer 41

The tendency of a molecule to bind with oxygen, Hb affinity depends on the conditions.

Question 42

Partial Pressure

Answer 42

PO2, as it increases so does Hb’s affinity. So oxygen is loaded where theres a high PO2

Question 43

Hb cycle

Answer 43

1. Hb is fully loaded in the lungs where theres a high pO2, almost all Hb forms OHb as it passes through the alveoli
2. As blood flows through the tissue OHb responds to a lower PO2 by unloading some O2, it diffuses through capillaries
3. As more oxygen is used up by respiration OHb dissociates more.

Question 44

Fetal Haemoglobin

Answer 44

Fetal blood gains all oxygen from the mothers placenta. The PO2 in the placenta is relatively low so OHb unloads O2. The fatal blood can load the oxygen at the low PO2 because it has a higher oxygen affinity

Question 45

CO2 Transportation Methods

Answer 45

1. Dissolved in plasma
2. Combines with Hb to form Carbaminohaemoglobin
3. Forms Carbonic Acid

Question 46

CO2 Removal with Carbonic Acid

Answer 46

Carbonic Acid formed by CO2 and water, catalysed by Carbonic anhydrase. The acid dissociates into H+ and HCO3-
H+ ions bind with Hb to form Haemoglobinic acid which leads to more O2 being released. HCO3 dissolved into plasma

Question 47

Chloride Shift

Answer 47

LEFT
H+ ions lead to increase in cell acidity,Hb acts as a buffer. Therefore it unloads more O2. Charge is maintained by the movement of Cl- ions in to the cell from the plasma

Question 48

Bohr Shift

Answer 48

RIGHT
Haemoglobinic acid causes the dissociation of O2, this is the Bohr effect as O2 released more readily in areas with more CO2. Means more O2 is delivered to respiring cells.