Transport in Animals Flashcards
1
Q
Why do multicellular organisms need a transport system?
A
- high metabolic demands, high demand for O2, so diffusion over long distance is not enough.
- low S.A to volume-the bigger the multicellular organism the smaller S.A.Small surface area=less absorption space.
- hormones needed in 1 place needed in another
- waste products need to be removed from cells and transported to excretory organs
2
Q
What are the features that most circulatory systems have in common
A
- a liquid transport medium that circulate around the system (blood)
- have vessels that carry transport medium
- have a pumping mechanism to move the fluid around system.
3
Q
what is a mass transport system
A
a mass of fluid with a mechanism for moving the fluid around the body
4
Q
what is meant by a closed circulatory system
A
- the blood is maintained inside vessels
- blood pumped at high pressure,quickly,
- returns straight to heart
- blood not incontact with tissues,cells.
5
Q
Define haemocoel
A
open body cavity in animal
6
Q
what is meant by an open circulatory system
A
blood pumped straight from heart into body cavity
- low pressure
- blood directly in contact with tissues,cells.
7
Q
How do substances enter blood in closed system
A
By diffusing across cell wall of blood vessels.
8
Q
what is meant by single circulatory system
A
Blood flows through heart, pumped to rest of body before returning to heart.
travels through heart x1
9
Q
Why is single closed circulatory system not efficient
A
blood returns to heart slowly because blood pressure decreases when passing through 2 sets of narrow capillaries
10
Q
how is activity levels affected by closed single/double circulatory systems
A
closed single circulatory systems-low activity level
closed double circulatory systems-high activity level
11
Q
Explain why double closed system is the most efficient
A
blood transported quickly due to high bp.High bp is achieved due to the blood going through 1 capillary network in each circuit.
12
Q
What are pulmonary and systemic circulations
A
pulmonary-blood circulation from heart to lungs and back
systemic- blood circulates from heart to other organs and back
13
Q
Do fish have a double/single closed/open circulatory system and explain why?
A
double closed circulatory system
oxygenated blood pumped from heart into arteries,which split into capillaries.This is where O2/glucose diffuses to cells.Veins take blood back to heart
14
Q
why kind of circulatory system do insects have?
A
open circulatory system
15
Q
what is insect blood called?
A
haemolymph
16
Q
Explain how blood is circulated in insects.
A
- blood enters heart through pores called ostia.
- Heart pumps blood towards head through mechanism peristalsis.
- At forward end of heart blood pours into body cavity.
-tube-like muscular pumping organ similar to heart pumps blood upwards
17
Q
what affects circulation in insects
A
body activity
18
Q
How is the transport system different in active/larger insects
A
-open-ended tubes attached to the heart. – direct the blood towards active parts of the body, eg wings.
19
Q
Function of smooth muscle,collagen and elastic fibres?
A
smooth muscle-contracts and relaxes, changing lumen size
collagen-provides structural maintain shape and volume of vessel
elastic fibres- stretch and recoil giving walls flexibility.
20
Q
How does the structure of an artery relate to its function?
Draw an artery w annotations
A
structure: has thick smooth muscle,collagen,elastic fibres,folded endothelium
function: transport blood from the heart
elastic fibres help maintain high bp by stretching and recoil
thick smooth muscle- stops artery from bursting
21
Q
How is a continuous flow of blood achieved in arteries
A
arteries contain elastic fibres.
which allow walls 2 stretch w high volumes of blood and recoil 2 original size when blood passes.
If no elastic was present artery wouldn’t expand & blood would stop/slow down
22
Q
How does the amount of elastic and smooth muscle change in arteries
A
close 2 heart-more elastic fibres- high pressure
further away/arterioles-more muscle to control amount of blood to certain organs.less pulse surge
23
Q
How does the structure of an arteriole relate to its function
A
function-links capillaries and arteries, so bp needs to be carefully controlled.
so has more smooth muscle allowing it to vasodilate/vasoconstrict
24
Q
How are capillaries adapted for its function
A
Function-transport blood for gas exchange.
- provide large S.A for diffusion to occur.
- cross section of capills are bigger than arterioles forcing the blood flow to decrease and thus giving more time for gas exchange .
- walls 1 cell thick
25
In what instances do arteries carry deoxygenated blood
pulmonary artery-blood going to lungs
umbilical artery(during pregnancy)-deoxy blood from fetus 2 placenta
26
what are pulses?
Surges of blood being pumped from heart
27
what is blood transported by arteries usually like
oxygenated
28
what is blood transported by veins usually like
deoxygenated .From cells to heart
29
In what instances do veins carry oxygenated blood
pulmonary vein-blood from lungs to heart
| umbilical vein-blood from placenta to fetus
30
How does the structure of venules relate to its function?
function: collect blood from capillary bed and lead to veins
structure: very thin walls with a thin layer of smooth muscle,collagen elastic fibres
31
Describe the path deoxygenated blood takes to get back to the heart
deoxy blood flows from capillaries to venules to larger veins then larger blood vessels and eventually inferior ,superior vena cava.
32
Can you check for a pulse in a vein.Explain answer.
No. Surge from heart pumping not there as blood pressure decreases when blood flows through capillaries.
33
Describe distribution of diff. tissues in veins
| Draw a vein w annotation
```
A lot of collagen
little elastic fibre
wide lumen
smooth endothelium lining#
valves-blood going up 2 heart,stopping backflow
```
34
How are veins adapted to prevent backflow
- one way valves -open when blood is going up to heart.Valves close when blood flows down.
- Big veins run between active muscles.Muscle contraction forces blood towards heart by squeezing veins.If muscle relax valves stop
- breathing movements act as a pump.Pressure change and squeezing pushes blood in chest veins to heart
35
What does blood consist of
- plasma:
- red blood cells
- platelets
- leukacytes (white blood cells)
36
What are the functions of blood
- acts as transport medium
- O2 to respiring tissue,removes CO2 & waste
- carries hormones -part of cellular control
- distributes heat around body,regulates body temp.
- acts as buffer,minimising PH changes
37
what does plasma consist of
O2,CO2
| glucose,hormones,amino acids,mineral ions,hormones,large plasma protein
38
Define oncotic pressure
tendency of water to move into blood by osmosis
| generated by plasma protein
39
define hydrostatic pressure
pressure from surge of blood produced by heart contracting
40
what is the difference in composition between tissue fluid and plasma
tissue fluid doesn't have large plasma protein and red blood cells the rest is the same
41
how is filtration pressure worked out
filtration pressure=hydrostatic-oncotic pressure
42
what does a positive and negative filtration pressure mean
positive- fluid moves out of capillaries
| negative- fluid moves into capillaries
43
What is the purpose of tissue fluid
used to exchange nutrients and gasses between cells of body and blood in circulatory system.
44
Where is tissue fluid formed?
In capillary bed
45
How is tissue fluid formed
At the arteriole end of capillary bed high hydrostatic pressure(hp) in blood forces/ ultrafiltrates fluid out
Large proteins remain in capillary
46
How is tissue fluid returned to blood in capillary
Low water potential in capillary / blood;
Due to (plasma) proteins;
Water enters capillary / blood;
(By) osmosis;
leftover tissue fluid gets returned to blood by lymphatic system
47
How does low protein conc. in blood affect tissue fluid formation
- water potential in capillary isn't as low/less negative
- less water reabsorbed into capillary
- more tissue fluid is formed at arteriole end
48
compare the composition of
```
red blood cells(rbc),
white blood cells,
platelets,proteins,
h2o
dissolved solutes.
```
in lymph blood and tissue fluid
rbc-only present in blood.2 big 2 get through capillary walls.
white bc-present in all.Few in tissue fluid,only when infection.Most in lymph
platelets-rbc only
proteins-present in all,few in tissue fluid,only antibodies in lymph
h2o- in all.tissue fluid,lymph have higher ψ than blood
dissolved solutes- in all
49
What is the role of the lymphatic system.
defence mechanism.
| increase of lymphocytes and produce antibodies which are passed on into blood.
50
Why do doctors examine lymph nodes.
enlarges lymph nodes are a sign that body is fighting off pathogens.
51
How does lymph fluid return to blood
lymph capillaries join together to make large vessels which eventually lead to blood/veins
52
How are erythrocytes adapted for fast oxygen diffusion?
biconcave shape-increases SA for diffusion of gases.
flexible -Helps pass through narrow capillaries.
No nuclei. more space for haemoglobin and transport of O2.
53
outline the structure of Haemoglobin
large globular conjugated protein.
4 polypeptide chains
each w an iron haem prosthetic group
54
what is formed when oxygen associated with haemoglobin
oxyhaemoglobin
55
Equation for formation of oxyhaemoglobin
4O2+ Hb Hb(O2)4
56
what is pO2 and how does it affect haemoglobin affinity for O2.
pO2-partial pressure of O2.
measure of oxygen conc.
the higher the pO2 the the greater affinity for oxygen.
57
Explain how oxygen diffuses into the blood refer to pO2
when blood arrives at capillaries,low conc of O2. there's a high pO2 in alveoli this steep conc. gradient makes it easy for oxygen diffuse through.
58
What is positive cooperativity in Hb
first oxygen bound to Hb causes Hb molecule to change shape making it easier for next O2 to bind and so on.
59
Draw an adult human oxygen dissociation curve
annotate where Hb is at each stage.
s-shaped graph
low pO2-respiring tissue
high pO2-lungs
60
How does the saturation of Hb affect affinity.
at low/high pO2 Hb has lower affinity for O2 as its hard for the 1st molecule to bind to Hb.
medium pO2- high affinity for O2 after 1st molecule other oxygens bind more rapidly
61
Draw a fetal disassociation curve against a adult one
fetal is higher,same shape
62
Why does fetal Hb have a higher affinity for oxygen?
fetal deoxygenated blood runs next to mother's oxygenated blood.This is where fetus gets oxygen from.In order for oxygen from mother's blood to bind to fetal Hb it needs to have a higher affinity,otherwise no O2 would be transferred to fetal blood
63
what is the bohr effect
when more oxygen is being released where more carbon dioxide is produced in respiration. This is just what the muscles need for aerobic respiration to continue.
64
What are the 3 different ways CO2 is transported to lungs?
1. 5% dissolved in plasma
2. 10-20% combine with amino group of Hb forming carbaminohemoglobin
3. 75-85% converted to hydrogen carbonate(HCO3) in cytoplasm of rbc
65
What enzyme catalyses reaction between CO2 + H2O
carbonic anhydrase
66
Explain what happens in rbc when CO2 +H2O
hydrogen carbonate is formed which disassociates into HCO3- and H+.
H+ binds with Hb forming haemoglobinic acid (HHb) .Hb acts as a buffer,maintaing PH.
HCO3- diffuse out of rbc into the plasma
Cl- moves into rbc to balance out charge
67
How is PH controlled in red blood cells?
haemoglobin acts as a buffer and H+ binds with it stopping rbc from becoming acidic.
chloride shift-chlorine ions diffuse into cell to balance out acidic PH
68
Draw and label the external structure of the heart
```
right atrium
right ventricle
right coronary artery
superior and inferior vena cava
aorta
pulmonary artery
pulmonary vein
left atrium
left ventricle
cardiac vein
```
69
Draw and label the internal structure of the heart
```
superior vena cava
right atrium
right atrioventricular(tricuspid) valve
right ventricle
inferior vena cava
semilunar valve
pulmonary artery
aorta ,carotid arteries
pulmonary veins
left atrium
left atrioventricular(bicuspid) valve
```
70
outline deoxygenated blood pathway
- deoxy blood enters right atrium via vena cava at low pressure
- atrioventricular(tricuspid) valves open and blood flows into right ventricle.
- av valves close
- deoxygenated blood pumped through semilunar valves & into pulmonary artery which brings blood to lungs
71
outline oxygenated blood pathway
-pulmonary vein bring oxy blood back into left atrium.
-av(bicuspid) valves open
-atria contract,forcing blood into left ventricle.
-
72
define systole and diastole
systole-cardiac contraction
| diastole-relaxation
73
outline the cardiac cycle
systole:
- ventricles relaxed
- the atria contract
- volume↓, pressure ↑ in atria,this forces blood into ventricles
- via AV valves.
- ↑ pressure as ventricles receive blood.
- atria relaxed.
- ventricles contract
- pressure ↑ in ventricles than atria,forces AV valves shut,prevent backflow
- pressure in ventricles ↑ than aorta forcing SL valves open
- forces blood into arteries
diastole:
- ventricles relaxed
- atria relaxed
- blood returns to atria which starts to fill up again ∵ ↑ pressure in artery
- ↑ volume and pressure in atria than ventricles
- this forces AV valves open and blood passively moves into ventricles.
74
Draw a graph showing pressure changes in heart
practise questions cgp
75
equation for cardiac output
cardiac output= heart rate x stroke volume.
76
role of SAN?
- Sets rhythm for heart beat by sending waves electrical activity over atrial walls.
- PACEMAKER
- ensuring atria contract same time
77
SAN?
sino-atrial node
78
AVN?
atrio-ventricular node
79
Apex?
bottom of heart
80
Outline how the heartbeat is initiated and coordinated
initiated at the SAN causing atria to contract
layer of non-conducting tissue prevents excitation to be passed on
electrical waves transferred to AVN which imposes a slight delay before sending to Bundle of His.
- Bundle of His splits into 2 branches and at apex purkyne fibres spread next to ventricles walls.
- excitation spreads & ventricles contract starting at apex.
81
ECG?
electrocardiogram
82
Why are ECG used
-help diagnose heart problem and treat correctly and fast
83
Draw a normal ECG
kerboodle pg 190
84
what is tachycardia and when would it be normal
| draw an ECG
- rapid heart beat,over 100bpm
| - normal: exercise,fever,frightened ,angry
85
what is bradycardia and when would it be normal
| draw an ECG
-heart rate lower than 60bpm
normal:
for fit people-have slower heart,beats efficiently.
86
what is ectopic heartbeat and when would it be normal
| draw an ECG
extra heartbeat out of rhythm.
once a day=normal
87
what is atrial fibrillation and
| draw an ECG
- abnormal rhythm of the heart.
- fibrillate up to 400bpm
- rapid electrical impulses are generated in atria
- don't contract properly so only some impulses passed on to ventricles
- no effective blood pumping
88
Plan a dissection of a mammalian heart
1.Place heart on dissecting tray
EXTERNAL
2.look at the outside of the heart, try to identify the 2 main vessels attached to it.Arteries thick and rubbery
3. Identify right,left atria,right and left ventricles.Measure + record thickness of ventricle walls,note differences.
4. Identify the coronary artery on the external surface. Locate where the coronary artery connects to the aorta.
4. sketch external heart structure
INTERNAL
5 - clean scalpel,cut along lines to look inside the left ventricle, and use scissors to cut through the wall of the left atrium. Follow the cut down to the apex of the left ventricle.
6.Open up the left atrium and left ventricle to examine them. Look for tendinous cords
(heart strings), observe how they are attached to the atrioventricular valve.
7. Look at the atrioventricular (AV) and semilunar (SL) valves. The AV valve has
two flaps so is called the bicuspid valve. The SL valve has a half-moon shape, hence
its name.
8. Make a similar cut down the right side of the heart to open up the right atrium and
ventricle. Examine the wall and internal structures.
9. Look for the AV valve on this side. It has three flaps so is called the tricuspid valve.
Look for the SL valve.
10. Use a ruler to measure the thicknesses of the walls of the left and right ventricles and
atria.
11. Draw a scientific annotated drawing to show all the identified structures. Include
detail about each structure beside each label
89
how to draw a scientific diagram
```
lines must be continuous
no overlap
no shading
Magnification must be on diagram
Diagram should cover half of A4 sheet.
```
90
Overcoming Risks
when cutting,cut away from body
