Transport in animals Flashcards
(30 cards)
Hydrostatic pressure
(Arterial)
Forces the fluid out of the blood into the tissue
Oncotic pressure
Presence of plasma proteins reduces WP in cappilairies and draws water in by osmosis
Venous
+ oncotic
-Hydrostatic - as water has left
+ water and tissue fluid reabsorbed back into the blood
Remaining 10% of tissue fluid
Lymph capillaries - lymphatic system - valves - blood
Conjugated protein
Haemoglobin (iron ion haem group)
Curve
Oxygen dissociation curve
-At tissues low PO2 and does not readily associate (aerobic respiration)
-At lungs high PO2 and readily associates
Bohr effect
H+ ions in blood plasma lower pH
-Haemoglobin (buffer) change in pH causes tertiary shape to change so lower affinity for O2 as cannot easily bind and easily dissociates
Fetal haemoglobin
Maternal (high level of O2)
Fetal blood (low level of O2)
So O2 diffuse down concentration into fetal blood
Fetal haemoglobin - to make transfer more efficient
1) Fetal has a higher affinity for O2
2) Co2 diffuse from fetal blood into maternal
-However only slightly greater affinity as otherwise O2 will be prevented from unloading in the fetal tissues
One heartbeat
60/ distance of P
Bradycardia
Larger distance between P waves 1 second +
-Higher stroke volume as more athletic
Tachycardia
Shorter distance between P wavs
-Long term problems with SAN
Ectopic
Extra heartbeat - contracts before the normal rhythm continues
Atrial fibrillation
Irregular waves of electrical excitation pass over the atria
-Atria contract randomly and rapidly
-Most cases electrical excitation not transmitted to the ventricles
Mammals vs Fish circulatory system
Mammals:
-Double circulatory
-Closed
-Higher BP
-2 sets of capillaries
-more efficient
-Higher demand for O2
Fish
-Single circulatory
-Closed
-Lower BP
-1 set of capillaries
-less efficient
-lower demand for O2 as ‘cold-blooded’
Mammals vs Frog circulatory system
Mammals:
-Double
-Blood from heart transported separately from lungs to the body
-Oxygenated and deoxygenated never mix
Frog:
-Double
-Blood from heart transported together from lungs to the body
-Oxygenated and deoxygenated mix
-O2 blood separate when returning to lungs
-Spiral valve partly separates blood
Ref.structure
Mammals vs Frog circulatory system effectiveness
Frog:
-Less effective as less O2 available but effective for frogs needs as lower metabolic rate
-Maintains body temp by other means
-Beat faster (to compensate)
-Circulation may limit its size
Mammal:
–Maximum O2 available
-Higher metabolic rate
-Uses metabolism to maintain body temp
Artery function and structure
Function: carry blood away from the heart
under high pressure (so they have to withstand
this pressure and force).
Structure: (Thicker) elastic layer / elastin,
enables them to withstand, pressure / force.
(Thicker) elastic layer / elastin, enables them to,
stretch recoil.
Ref. elastic layer evens out surges from the
pumping of the heart and allows a continuous
flow of blood (Windkessel effect).
Collagen provides, structure / support.
Collagen maintains shape and volume (limiting
stretch).
Smooth muscle contracts and relaxes to,
change the size of the lumen / control blood
pressure.
Smooth muscle provides strength to withstand
the pressure.
Veins function and structure
Function: Veins carry blood back to the heart.
No, pulse / surge from heart. Blood in veins is
under less pressure (than in arteries). Needs to
move against gravity.
Structure: Thinner elastic layer (no, stretch /
recoil / pulse).
Have valves to prevent backflow of blood.
More collagen than arteries to give structural
support as they carry large volumes of blood
Capillaries function and structure
Function: Allow substances, to be exchanged /
diffuse, between blood and, tissue fluid /
surrounding cells.
Structure: Walls are one cell thick.
Short diffusion distance.
Only large enough to allow red blood cells to
travel through in single file (to increase contact
of RBCs with capillary wall).
Small enough to form network needed to
exchange substances.
Similarities in ultrafiltration in capillaries and Kidney
1) Small molecules are filtered
from/diffuse out of the blood.
2) Both processes occur in capillaries.
3) Large molecules/proteins/ cells, remain
in the blood.
4)High (hydrostatic) pressure in both
processes.
5) Many molecules (e.g. water, sugars,
ions) are reabsorbed back into
capillaries.
6) Blood vessels become narrower to
maintain (hydrostatic) pressure
7) Hydrostatic pressure greater than
oncotic pressure in both
8) Neutrophils / lymphocytes, can pass
through in both
9) Both involve basement membranes
Differences in ultrafiltration in capillaries and Kidney
1) Filtrate enters the Bowman’s
capsule and then the PCT in the
kidney, but tissue fluid bathes
cells/enters intercellular space.
2) Molecules that are not reabsorbed
by capillaries form urine in the
kidney, but molecules that are not
reabsorbed from tissue fluid will,
enter cells / form lymph.
3) Blood filtered through 3(named)
layers in ultrafiltration, but only 1
(named) layer in formation of tissue
fluid
4) knot of capillaries in ultrafiltration
but a network of capillaries in
formation of tissue fluid
Atrial fibrillation
Atria are contracting more frequently than the ventricles
-Irregular and weak
-Insufficient blood forced into the ventricles
-Although ventricles contract there is less blood in the heart
-Less O2 reaching the tissues
Atrial diastole / ventricular diastole
-atria relax
- ventricles relax
-blood flows through, atrioventricular / AV /
bicuspid / tricuspid, valve(s) OR ref. to their
opening (more)
- blood enters atria (passively)
- blood enters ventricles (passively)
