chapter 8 Flashcards
Transport systems in multicellular animals
what are elastic fibres
stretch and recoil and allows for flexibility
what is collagen
structural support
what is smooth muscle
changes size of lumen
contracts and relaxes
arteries
oxygenated blood away from heart
apart from heart to lungs pulmonary artery
contains smooth muscle, elastic fibres and collagen
the endothelium lining is smooth so blood can flow easily
lumen endothelium elastic muscle collagen
veins
away from the cells into the heart
de oxygenated blood
apart from the lungs to the heart (Pulmonary vein)
don’t have a pulse
low pressure
valves
muscles contract to squeeze the blood out
breathing acts as a pump which moves blood through veins to heart
wide lumen with smooth endothelium
elastic fibres, muscle and collagen
venules link capillaries to veins
capillaries
lumen is small so single file red blood cells
capillary walls made of endothelial cells
blood from areoles is oxygenated
blood going to he venules is has less oxygen and more CO2
single endothelial cell thick for diffusion
large surface area
rate of blood flow is low which means more time for diffusion
why do we need a specialised transport system
high metabolic demands (need O2 food and need to get rid of waste products like CO2)
SA:V ratio gets smaller as the animal gets bigger so diffusion and absorption wont transport enough
hormones needed to be transported from places round body
open circulatory system
few vessels
pumped straight from heart to body cavity (haemocoel)
low pressure
direct contact to tissues and cells for exchange
returns to the heart through open ended vessels
blood is called haemolymph
doesn’t transport O2 or CO2 as that’s spiracles
transports food and nitrogenous waste products (urea)
closed circulatory system
enclosed in blood vessels
no direct contact with cells
diffuses through vessel walls
blood pigment carries gas
single closed circulatory system
blood only travels once through the heart
heart - gills - body - heart
capillaries at body and gills allows for diffusion
low pressure so more time for diffusion
takes long time to get back to the heart
double closed circulatory system
animals with high metabolic needs
most efficient system
2 separate systems:
-heart to lungs picks up O2 and
releases CO2 then back to heart
-from heart round body then back to
heart
only passes through one set of capillaries so high pressure and fast flow of blood
what are the functions of blood
O2 and CO2 from and to cells
digested food from intestine
nitrogenous waste gone
chemical messages
platelets to damaged areas
cells and antibodies
food molecules from storage compounds
what is lymph
it’s made up of the tissue fluid that does not return to he blood
transported through lymph cappilleries
squeezing of body muscles move lymph which
returns to veins
lymph nodes produce lymphocytes
they also detect bacteria and debris
enlarged lyph nodes means the body is fighting against pathogens.
diastole
heart relaxes
pressure is building as blood enters either atium or venticles
arteries has low pressure
systole
atrium and venricles contracts
pressure is very high in heart
at end of systole pressure is low in heart and blood pressure in arteries are high pressure
the heart sound
“lub-dub”
“lub” is the bi and tricuspid valves as blood is forced aginst it as ventricle squeezes (contracts)
“dub” is the backflow of blood on the semilunar valves in he aorta and pulmonary valves
tachychardia
fast heart beat 100+
excersise, fever or frightened
brachycardia
slow heart beat 60-
fit and healthy
ectopic heartbeat
extra beats out of rythem
happens once a day on average
atrial fibrilation
abnormal rythem
atria contract very fast 400 per minute
not fully contracted
not effective
Plasma
The main component in blood. A yellow fluid containing many dissolved substances and carrying the blood cells.
platelets
Components of large cells (megakaryocytes), found in bone marrow, involved in clotting mechanisms.
What substance in plasma cant pass through the capillary walls?
large plasma proteins
Why does water move into the blood in the capillaries from the surrounding fluids
Blood has large plasma proteins that cannot leave through the capillaries, this gives the blood a high solute potential and low water potential which means water moves in by osmosis.
Oncotic pressure
The tendency of water to move into the blood by osmosis as a result of the plasma proteins.
Hydrostatic pressure
Pressure created by water in a closed system
Composition of tissue fluid
Dissolved substances, white blood cells, platelets
No red blood cells no plasma protein
What is dissolved in plasma and tissue fluid?
Glucose, amino acids, mineral ions, hormones
Lymph composition
Similar to plasma and tissue fluid
Less oxygen and fewer nutrients
Also has fatty acids
Lymph capillaries
Join to form larger vessels. Move by the squeezing of muscle. Have one way valves. Eventually return to the blood into the right and left subclavian vein
Lymphocytes
White blood cells that make up the specific immune system. They build up in the lymph node and when necessary produce antibodies which then pass into the blood
Lymph node
They intercept bacteria and debris from the lymph. Contains phagocytes to ingest the bacteria.
Enlarges lymph nodes = the body id fighting invading pathogens.
How do oxygen and haemoglobin bind, what do they form?
Hb + 4O2 — Hb(O2)4
Haemoglobin + Oxygen — Oxyhaemoglobin
It is a reversible reaction`
How many oxygen molecules can haemoglobin bind to at once?
4
High affinity
Oxygen can bind easily to the haemoglobin but struggles to be released.
Low affinity
Oxygen finds it hard to bind but can be released easily
Oxygen dissociation curve
Shows how saturated the haemoglobin molecule is with oxygen at any given partial pressure
How saturated the haemoglobin is depends on
Whether it has a high or low affinity
When the first oxygen molecules binds what happens?
Causes a change to the structure of the haem group with makes it easier for the next oxygen molecules to bind
Why is the oxygen dissociation graph an S shape?
Difficult for the first oxygen to bind, then easier for the next ones as the haem group has changed shape then it is hard again as the haemoglobin becomes more saturated
Steep parts of the oxygen dissociation curve mean that
O2 binding is easy as haemoglobin has a high affinity
Shallow sections o the oxygen dissociation curve mean that
O2 binding is difficult as haemoglobin has low affinity
A shift of the curve to the right means
The haemoglobin has a low affinity for oxygen.
The Bohr effect
The shift of the oxygen dissociation curve to the right.
the greater the concentration of CO2, the more readily haemoglobin releases O2
What does a greater concentration of CO2 mean?
The more readily haemoglobin releases O2
What happens to the partial pressure of Co2 during exercise
The partial pressure increased because cells respire and release CO2
What happen to the curve during exercise?
`It shifts to the right
What happens to the rate of dissociation during exercise? why?
Greater concentration of CO2 in respiring tissues = dissociation happens faster
What happens to the affinity of haemoglobin during exercise?
Its low and oxygen can dissociate easily
How does a fetus get oxygen from its mother?
Oxygenated blood from the mother runs closely to the deoxygenated blood from the fetus in the placenta. Fetal blood has a higher affinity for oxygen that mother = removes oxygen from mothers blood as they pass.
3 ways that carbon dioxide is transported
- Dissolved in the plasma
- Combined with haemoglobin
3.Converted into hydrogen carbonate
What is the reaction that happens between CO2 and H2O
CO2 + H2O <—> H2CO3 <—> H+ + HCO3-
Carbon dioxide + Water — Carbonic acid — (dissociates) — hydrogen +hydrogen carbonate
What is the enzyme involves in the formation of carbonic acid?
Carbonic anhydrase
What makes oxygen move into the red blood cells when in the lungs
When they first enter they have low levels of oxygen = steep concentration gradient between cell and air in the alveoli = moves in and binds to haemoglobin
What happens when the oxygen enters the red blood cell?
Oxygen binds to the haemoglobin which changes the shape of the haem group which makes it easier for the next oxygen molecule to bind
Oxygen dissociation curve
Percentage saturation haemoglobin in blood and partial pressure of oxygen are plotted. It shows the affinity of haemoglobin for oxygen
What are the results of the Bohr effect
In active tissues with high partial pressure of CO2 = haemoglobin gives up its oxygen
In the lungs where the proportion of CO2 in the air is low, oxygen binds to the haemoglobin molecules easily
What happens in the lungs if the level of CO2 rises?
Oxygen binds to haemoglobin molecules easily
What happens in active tissues of the level of CO2 increases
Haemoglobin gives up its oxygen more easily
Why does oxygen move from the maternal blood to the fetal blood
Fetal blood has higher affinity for oxygen
Carbaminohaemoglobin
Carbon dioxide and haemoglobin combine
