gas exchange

Question 1

epithilium in bronchiols vs alevoli

Answer 1

B= cubodial
A= squamous

A= secretes surfactant
B= illiated epithilim

Question 2

TF VS BLOOD

Answer 2

• less glucose/AA
• no RBC + platelets
• less WBC
• higher conc of c02 + less o2
• fewer large proteins

Question 3

bohr effect

Answer 3

• co2 diffuses into RBC down conc gradient
• CO2 reacts w water = carbonic acid via carbonic anydrase
• carbonic acid dissociates = H+ and hydrogencarbonate ions
• Hemoglobonic has higher affnity for H+ than O2= Hemoglobonic acid
• O2 unloaded into repiring tissue
• H acts as buffer to maintain pH of blood
• Hydrogencarbonate ions diffuse out of RBC
• Chloride shift- cholride ions enter
• O2 unloaded
• forming carbaminohemglobin
• Hb dissociates curve to right

Question 4

TF + lymph formation

Answer 4

• at arteriole end = high HP
• small mol e.g AA/glucose PUSHED out = TF via capillary pore
• Large mol e.g RBC remain in capillary = low Ψ in venule end of Capillry
• Small mol in TF move back into venule end via osmosis + diffusion for CO2, glucose
• TF picked up by lymp vessles = lymph fluid

Question 5

Arterial end:BLOOD vs TF

Answer 5

• RBC too large to leave capillary
• PLasma proteins too large to leave capillary
• higher conc of 02 from lungs NOT offloaded from Hb
• higher conc of glucose from absorption
• more CO2 + lactate entering blood

Question 6

high altitude

Answer 6

• pp of 02 in air reduced
• less steep O2 conc gradient
• Hb 70% saturated w O2
• to compensate:
  increased RBC
  Increased Hb
  increased myglobin
  increased mitochondria

Question 7

Veins

Answer 7

• presence of valves
• wide lumen relative to thickness of wall
• thin tunica media/smooth mucle
• thin tunic externa
• smooth tunica interna

Question 8

Capillary

Answer 8

• Squamous epithilum= short diffusion dist of O2 = faster/increased rate of diffusion of 02
• small diamteer = closer to tissue for efficent diffusion
• plasma/blood containing glucose/o2= obtain sufficent nutrients

Question 9

CARDIAC CYCLE (COCO)

Answer 9

1. SAN pacemaker
   - atria fill w blood = max pressure + max vol
   - SAN sends out waves of excitation/depolarisation to ATRIAL WALLS
   - atria contract + atrial systole
   - Blood pushed through open AV valves
   - Pressure in ventricles higher than atria
   - AV Valves shut to prevent backflow of blood
   - Non conducting fibres = prevent simaltenosu contraction aft short delay of 0.1s
   - AVN picks up impulse + transmitted down purkinje fibres and bundle of his to apex
   - to walls of ventricles + V contract pushing blood from bottom up = Ventricular systole
   - Blood pushed through SL valves
   - into aorta + pA = pressure in aorta higher than V + SL shut to prevent backfow of blood

Question 10

why does lack of protein cause odema

Answer 10

• no channel proteins to transport polar mol through CSM
• Fluid remains freely in circulation or excess fluid in circulation = swelling
• no carrier protein to transport polar subst like AA across TF/CSM
• more fluid by osmosis so buildip in TF

Question 11

explain hwo ss of tunica media diff to ss of tunica media in MUSCULAR ATEREY and to function of aorta

Answer 11

• tunica media of aorta = more elastin + less smooth muscle than muscular artery
• allows aorta to stretch + less likely to burst as result of high BP during ventricular systole
• aft stretching aorta recoil
• maintains BP + evens out BF

Question 12

explain why its neccessary for athletes to increase conc of Hb in their blood when acclimatising high altitude

Answer 12

• low pO2 –> less oxygen in lungs
• Hb less saturated w O2
• to compensate
• more RBC + more Hb
• increased myoglobin
• same vol of O2 transported in blood at sea level