Transport In Animals Flashcards
1
Q
Factors that influence the need for a transport system
A
- size
- surface area to volume ratio
- level of metabolic activity
2
Q
How does size effect transport in animals
A
- larger diffusion pathway
- lower diffusion rate
- less supplies reach the inner cells in the body
3
Q
How does the level of metabolic activity effect an animals need for a transport system
A
How active the animal is
- more active
- need better supply of nutrients and oxygen
- keep themselves warm: mammals
4
Q
What are features of a good transport system
A
- fluid to carry nutrients, oxygen and waste around the body: blood
- a pump to create pressure to push the fluid: heart
- exchange surfaces: capillaries
- tubes or vessels to carry the blood by mass flow
- two circuits: one to pick up and one to drop of blood
5
Q
What is a single circulatory system
A
The blood flows through the heart once for each circuit of the body
6
Q
What is a double circulatory system
A
- system has two separate circuits
- flows through the heart twice in each circuit of the body
- pulmonary circuit: blood to the lungs
- systematic circuit: blood flows to the rest of the body
7
Q
Advantages of a double circulatory system
A
- faster blood flow
- higher blood pressure
- heart can increase the bloods pressure
8
Q
What are open circulatory systems
A
Where the blood is not held in blood vessels
- circulates around cavities
- cells and tissues bathed directly in blood
9
Q
How is blood moved in open circulatory systems
A
Movement of the body
- contraction of muscles
10
Q
What is an ostia
A
Gaps where blood enters the heart in insects
11
Q
Disadvantages of open circulatory systems
A
- blood pressure is low
- blood flow is slow
- circulation of blood may be affected by body movement/lack of
12
Q
What are closed circulatory systems
A
Blood is transported around the body in blood vessels
13
Q
Advantages of closed circulatory systems
A
- higher pressure, faster blood flow
- faster delivery of oxygen and nutrients
- faster removal of carbon dioxide and wastes
- not reliant on body movement
14
Q
What do arterioles do
A
Transport blood from arteries to capillaries
15
Q
What do venules do
A
Transport blood from capillaries to veins
16
Q
Where do arteries carry blood from
A
Away from the heart
17
Q
Why do arteries have thick walls
A
Withstand the pressure within the vessel
18
Q
Why do arteries have thin lumen
A
Maintain the high pressure
19
Q
What is the inner layer of arteries made from
A
Elastic tissue
- thin layer
- allows walls to stretch and recoil
- help maintain blood pressure
20
Q
What is the middle layer of arteries made from
A
Smoot muscle
- thick layer
21
Q
What is the outer layer of the arteries made from
A
Collagen and elastic tissue
- thick
- provides strength
- maintain pressure
22
Q
What happens in the arterioles and venules
A
- vaso-constriction
- vaso-dilation
23
Q
Why is the lumen of a capillary very small
A
- size of a red blood cell
- allows for quicker transmission of materials
24
Q
What type of cells makes the capillaries
A
Epithelial cells
25
What are the walls of the capillaries like
Leaky
- allow blood plasma and dissolved substances to leave blood
26
Where do veins carry blood
Back to the heart
27
Why is the lumen of veins large
Allow for easy blood flow
28
What are the layers of the veins
All thin
- collagen
- smooth muscle
- elastic tissue
29
What is the purpose of valves
Prevent the bank flow of blood
30
What substances are found in blood
- plasma
- white blood cells
- red blood cells
- platelets
31
What is in plasma
Dissolved substances
- oxygen
- carbon dioxide
- minerals
- glucose
- amino acids
- hormones
- plasma proteins
32
What is tissue fluid
Anything small enough to pass through the capillary walls, forming a fluid bathing cells in the body
- blood plasma minus large proteins
33
What does tissue fluid do
Provide cells with oxygen and nutrients they need
34
How does tissue fluid form
- atrial side: blood has high hydrostatic pressure
- causes plasma to be pushed out of capillary wall
- fluid leaves the blood
- tissue fluid surrounds the body cells allow for exchange
35
How does tissue fluid return to the blood
- most enters back into the capillaries (90%)
- rest enters the lymphatic system
- now called lymph
- lymph drained into blood stream via two ducts that join at the vena cava
36
What is hydrostatic pressure
The remaining pressure from the heart
37
What is oncotic pressure
Pressure made by substances
- proteins
- effects water absorption
38
What are lymph nodes
Swelling found at intervals along the lymphatic system
- important part of immune system
39
What happens to tissue fluid when a tissue in infected
- capillaries become more leaky
- allow for more lymph to reach the lymph node
40
What are coronary arteries
Supply the heart with oxygen
41
How does deoxygenated blood enter the heart
Vena cava
42
What side of the heart has deoxygenated blood
Right
43
What side of the heart has oxygenated blood
Left
44
How does oxygenated blood enter the heart from the lungs
Pulmonary vein
45
What is the role of tendinous cords in the heart
Prevent the valves from turning inside out
46
What separates the two ventricles
Septum
47
How does deoxygenated blood leave the heart
Through the pulmonary artery
48
How does oxygenated blood leave the heart
Through the aorta
49
What is blood pressure like in the atria
Low pressure
50
What side of the heart has thicker ventricular walls
Left ventricle
51
Why is the left side of the heart thicker
Has to pump blood around the systemic circulatory system
- rest of body
52
What is the structure of cardiac muscle
- fibers
- cross over each other
- lots of mitochondria
- intercalated discs
- sarcomeres
53
What are intercalated discs
Help facilitate in synchronizing contractions
54
What is the purpose of the heart
To create pressure to push blood around the blood vessels
55
What is atrial systole
The atrium contract, pushing blood into the ventricles
56
What is ventricular systole
The ventricles contract, pushing blood out of the heart
57
What is diastole
When the heart relaxes to allow blood to flow into atrium
- repolarisation
58
What are the functions of lymph
- drains excess tissue fluid
- absorbs digestive fats, in the ileum, via lacteals
- immune function: white blood cells develop in the lymph nodes
59
What is the structure of lymphatic vessels
- one way valves
- one layer of slightly overlapping calls
- fluid enters through gaps
- drained by muscle contraction
60
Similarities between lymph vessels and veins
- contain one way valves
- moved via muscle contraction
61
Differences between lymph vessels and veins
- no pump
- thinner, more permeable walls
62
What causes the AV valve to open
- after systole the ventricle relax and recoil
- pressure in ventricles < pressure in atrium
- blood in atrium pushes AV valves open
63
What causes the AV valves to close
- blood flows into the ventricles causing the pressure to slowly increase
- atrium start to relax
- valves close due to swirling action in the blood around the valves
- blood moves upwards filling valve pockets
64
What causes the first “lub” sound in the heart beat
- semilunar valves open
- AV valves close
65
What causes the second “dub” sound in the heart beat
- semilunar valves close
- AV valves open
66
What structure of arteries allow for a more even flow of blood
- artery walls close to the heart have a lot of elastic tissue
- when blood leaves heart, these walls stretch
- as blood leaves aorta pressure starts to drop
- elastic recoil helps maintain pressure
67
What is bradycardia
A slow heart beat
68
What is tachycardia
A fast heart beat
69
What is an ectopic heartbeat
An extra beat or early beat in the ventricles
70
What does it mean that the heart is myogenic
It is able to create its own contractions
71
What are fibrillations
The uncoordinated contractions of the atria and ventricle
72
What does the SAN do
Sino-atrial node
- generate electrical current
73
What causes the atria to contract
- wave of excitation from SAN spreads across both atrium
- travels along the membranes of muscle tissue
- as wave passes, causes cardiac muscle cells to contract
- atrial systole
74
What does the AVN do
Atrio-ventricular node
- conducts the wave of excitation down the ventricles
75
Why is there a delay at the AVN
Allow for all the blood to leave the atrium
76
How are the ventricles contracted
- wave of excitation passes down the bundle of His
- goes down the septum
- travels through the Purkyne fibers
- passes from the apex of the heart up
- causes the ventricles to contract
77
What does the P wave show
Atrial systole
78
What does the QRS complex show
Ventricular systole
79
What does the T wave show
Diastole
- repolarisation
80
What is atrial fibrillation
No clear P wave
81
What is the quaternary structure of haemoglobin
4 subunits
- one polypeptide chain
- haem prosthetic group
82
What does the haem prosthetic group do
Contains a single iron ion
- attract and hold an oxygen molecule
83
What curve shown oxygens affinity to harmoglobin
Sigmoidal curve
- dissociation curve
84
What is partial pressure of oxygen
The pressure it contributes to a mixture of gases
85
What happens to the haem group when oxygen binds
- changes shape of others
- makes it easier for oxygen to bind
86
What way does the curve move if there is a higher affinity to oxygen
Moves to the left
87
What is affinity to oxygen
How easily oxygen binds with the haem group
88
What ways can carbon dioxide leave tissues into the blood
- dissolved into plasma
- bind with haemoglobin to form carbaminohaemoglobin
- transported in the form of hydro carbonate ions (HCO3-)
89
What is formed when carbon dioxide binds with water
Carbonic acid
90
Chemical equation for the formation of carbonic acid
CO2 + H2O —> H2CO2
91
What forms when carbonic acid dissociates
- hydrogen ions
- hydrogencarbonate ions
92
Equation for the dissociation of carbonic acid
H2CO2 —> HCO3- + H+
93
What is the chloride shift
Movement of chloride ions from the plasma into the red blood cells
- result of hydrocarbonate ions leaving red blood cells
94
How are hydrogen ions removes from red blood cells
Associate with haemoglobin to produce haemoglobinic acid
95
What does haemoglobinic acid do
Act as a buffer to maintain pH
96
What is the Bohr effect
Describes the effect that an increasing concentration of carbon dioxide has on the haemoblobin
97
How does carbon dioxide effect pH levels
Decreases pH levels
98
which direction does a higher pH move the graph
Left
99
What way does the graph move if there is more carbon dioxide
Right
