MD3001 Orientation Week + Week 1

Question 1

percent of blood passing through pulmonary circulation

Answer 1

9% of blood passes through this

Question 2

percent of blood passing through systemic circulation

Answer 2

84% of blood passes through this

Question 3

percent of blood passing through heart

Answer 3

7% of blood passes through this

Question 4

percent of blood supplying brain

Answer 4

13% of blood is supplying this structure

Question 5

percent of blood supplying heart

Answer 5

4% of blood is supplying this structure

Question 6

what lie anterior to transfer pericardial sinus (2)?

Answer 6

1. aorta

2. pulmonary trunk

Question 7

4 borders of the heart

Answer 7

1. L 2nd CC
2. L 5th interspace space, midclavicular
3. R 3rd CC
4. R 6th CC

Question 8

where may structures w/ sensory supply via phrenic refer pain to?

Answer 8

pain from structures w/ sensory supply from this nerve may refer pain to shoulder tip (C4 dermatome)

Question 9

active competence

Answer 9

AV valves use papillary muscles/chordae tendinae to close

Question 10

3 structural components of R ventricle

Answer 10

1. trabecular carneae
2. 3 papillary muscles (ant, post, septal) w/ chordae tendinae
3. septomarginal trabecula

Question 11

length of pre vertebral fascia

Answer 11

this extends from base of skull to T3

Question 12

borders of retropharyngeal space

Answer 12

between buccopharyngeal and prevertebral fascia

Question 13

extent of pre tracheal fascia

Answer 13

extends from hyoid to fuse with pericardium

Question 14

2 branches of the external carotid artery

Answer 14

1. superficial temporal

2. facial

Question 15

sympathetic stimulation on pacemaker activity

Answer 15

NA acts on b1 receptors to increase cAMP production, increasing rate of SAN depo

Question 16

parasympathetic stimulation on pacemaker activity

Answer 16

Ach acts on M2 receptors which decreases CAMP production and reduces rate of phase 1 depo

Question 17

rate of depo in SA

Answer 17

rate of depo of this is 90/m

Question 18

conduction speed in internodal pathways

Answer 18

conduction speed through here is 1m/s

Question 19

conduction speed in AV node and bundle of His

Answer 19

conduction speed through here is 0.01m/s

Question 20

conduction speed in Purkinje fibres

Answer 20

conduction speed through here is 1.5-4m/s

Question 21

how does Ca2+ stay in high [ ] in cardiac T-tubules?

Answer 21

mucopolysaccharides sequester Ca2+ here

Question 22

how does ANS increase contractility (inotropy)?

Answer 22

NA on b1 increase cAMP which enhances Ca2+ influx and promotes storage and release of Ca2+ SER

Question 23

absolute refractory period and period of contraction of skeletal muscle

Answer 23

ARP: 1-2m/s

period of contraction: 20-100ms

Question 24

branches of R coronary artery (3)

Answer 24

1. nodal
2. marginal
3. posterior interventricular

Question 25

branches of L coronary artery

Answer 25

1. circumflex -> marginal | 2. LAD

Question 26

circumflex infarct

Answer 26

obstruction of circumflex artery

Question 27

site of coronary artery occlusion by atherosclerosis in order of frequency

Answer 27

1. LAD 2. R coronary artery 3. circumflex 4. L coronary artery

Question 28

Reynold's number

Answer 28

velocity x radius/viscosity

Question 29

LaPlace's law

Answer 29

T = PR

Question 30

2 protease inhibitors against HCV

Answer 30

1. telaprevir | 2. boceprevir

Question 31

2 entry inhibitors

Answer 31

1. T20 fusion inhibitor (Enfuvirtide): binds to gp41 | 2. CCR5 antagonist (Maraviroc): binds to CCR5, prevents interaction w/ gp120

Question 32

2 types of antiviral drugs used against influenza

Answer 32

1. viral uncoating inhibitor (amantadine/rimantadine): block M2 ion channel 2. virus release inhibitor (oseltamivir, zanamivir): neuraminidase inhibitor

Question 33

drugs to treat hep C (4)

Answer 33

1. ribavirin 2. peg-int-a 3. simeprevir, ledipasvir, sofosbuvir 4. protease inhibit (telaprevir, boceprevir)

Question 34

syncytiotrophoblasts

Answer 34

cells covering endothelium of foetal capillaries

Question 35

path of blood from SVC in foetal circulation

Answer 35

90% pass via ductus arteriosus into aorta. 10% passes to pulmonary circulation where it gives O2 to developing lungs

Question 36

closure of foramen ovale

Answer 36

first breath pulls blood into pulmonary circulation, which is returned to LA, increasing pressure in LA to equal RA

Question 37

obliteration of ductus arteriosus

Answer 37

``` initial phase (1st hour): smooth muscle contraction (increased O2 tension and decreased prostaglandins) later phase: thickening of tunica intima b/w 1-3months ```

Question 38

paradoxical emboli

Answer 38

embolism from DVT clotting patent foramen ovale

Question 39

where does venous end of heart tube receive blood from? (3)

Answer 39

1. cardinal 2. vitelline 3. umbilical

Question 40

what are endocardial cushions derived from?

Answer 40

this structure in developing heart is derived from neural crest cells

Question 41

what do endocardial cushions form? (4)

Answer 41

1. interatrial septum 2. membranous part of inter ventricular septum 3. AV valves 4. PT and aorta

Question 42

outline blood flow through foramen oval

Answer 42

RA -> foramen ovale in septum secundum -> foramen secundum in septum primum -> LA

Question 43

4 elements of inter ventricular septum formation

Answer 43

1+2. endocardial cushions form L and R conotruncal ridges 3. extension of inf. AV cushion contribute to membranous portion 4. ventricular growth forms muscular portion of IVS

Question 44

ventricle septal defect caused by no truncal ridges

Answer 44

persistent truncus arteriosus

Question 45

ventricle septal defect caused by no truncal ridge spiral

Answer 45

transposition of the vessels

Question 46

4 aspects of Fallot's tetralogy

Answer 46

1. VSD 2. enlarged R ventricle 3. overriding aorta 4. pulmonary stenosis

Question 47

characteristic of metarterioles

Answer 47

these vessels comprise of discontinuous smooth muscle