Assorted

Question 1

Inspiration process (4)

Answer 1

• Inspiratory muscles (diaphragm + ext. intercoastal) contract -> inc intracthoracic vol
• Ppl decr
• Ptp inc (alveoli expand)
• PA < Patm ->> air into alveoli

Question 2

Expiration process (4)

Answer 2

PASSIVE

• Ins muscles stop contracting
• Ppl inc
• Ptp decr (alveoli decrease)
• PA > Patm ->> air out until PA = Patm

Question 3

Factors influencing ventilation

(2)

Answer 3

(1) Distensibility (stretchiness):
- elasicity of lung tissue (elastin, collagen)
- surface tension (inc recoil, alveolar instability)
(2) Frictional resistance
- tissure resistance (20%)
- airway resistance

Question 4

B2 agonists (3)

Answer 4

SABA - salbutamol

LABA -salmeterol

-uLABA

Question 5

Anti-cholinergics (2)

Answer 5

SAMA - ipratropium

LAMA - tiotropium

Question 6

Methylxanthines (1)

Answer 6

theophylline

Question 7

Inhaled corticosteroids (2)

Answer 7

-budesonide, fluticasone

Question 8

Zygote -> Embryo (5)

Answer 8

• Zygote (cleavage)
• Morula (16 cells)
• Blastocyst (compaction, hatching)
• Bilaminar embryonic disc (epiblast + hypoblast)
• Embryo (gastrulation: ectoderm, mesoderm, endoderm)

Question 9

Germ layers: Ectoderm in adult (4)

Answer 9

• Epidermis of skin
• CNS
• Lens of eye
• Breasts

Question 10

Germ layers: Mesdoderm in adults (4)

Answer 10

• Blood vessels
• Muscle
• Bone (except part of skull)
• Urinary and genital (except epithelium)

Question 11

Germ layers: Endoderm (4)

Answer 11

• Epithelium of GIT
• Epithelium of resp tract
• Epithelium of bladder
• Parenchyma of liver, gall bladder, pancreas

Question 12

Drug metabolism by liver

(2 Phases)

Answer 12

Phase 1: Cytochrome P450 enzymes -> inc water solubility

Phase 2: Liver enzymes -> add large molecular groups for renal excretion

Question 13

Drug absorption

vs

Drug excretion

Answer 13

HA <-> H+ + A-

B + H+ <-> BH+

Ab: uncharged form diffuse across membrane

Exc: charged form excreted into urine

Question 14

Mechanisms of increased airway resistance (5)

Answer 14

• smooth muscle contraction
• wall thickening
• lumenal occlusion
• decreased lung elasticity
• obliteration (destruction of lungs)

Question 15

ECG

electro-mechanical delay

Answer 15

P wave (late diastole) -> atrial contract

QRS complex (end diastole) -> V contract

T wave (late systole) -> LV relax

Question 16

Preload (5)

Answer 16

• Inc preload = inc SV
• defn: tension of full LV
• approximate: LVEDV
• Eqn: Frank-Starling curve
• Chronic volume overload = eccentric hypertrophy (inc chamber size)

Question 17

Afterload (5)

Answer 17

• Inc afterload = decr SV
• defn: wall stress to overcome to eject blood
• approximate: systolic arterial pressure
• Eqn: Law of Laplace
• Chronic pressure overload = concentric hypertrophy (thicker wall)

Question 18

Contractility (2)

Answer 18

• related to ejection fraction (estimate systolic function)
• inc contractility = inc SV