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GSSE > Physiology > Flashcards

Physiology Flashcards

1
Q

Which NO synthase (NOS) is located in endothelial cells?

A

NOS 3

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2
Q

NO typically acts via which other 2nd messenger?

A

cGMP (direct activation of guanylyl cyclase -> Ca2+ influx -> cGMP activation

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3
Q

What is the half life of a neutrophil?

A

6hrs

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4
Q

What factors stimulate eosinophil maturation & activation?

A

IL-3, IL-5, GM-CSF

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5
Q

Give 3 examples of organ-specific tissue macrophages

A

Kupffer cells (liver); pulmonary alveolar macrophages, microglia (brain)

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6
Q

Only vasodilator/ vasoconstrictor fibres reach the liver (to both the portal vein and hepatic artery)

A

Vasoconstrictor (via 3rd-11th thoracic ventral roots/ splanchnic nerves to portal vein and hepatic sympathetic plexus to the artery)

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7
Q

What is the normal portal venous pressure?

A

10mmHg (compared to 5mmHg for hepatic venous pressure)

*Think 0 in p0rtal

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8
Q

List drugs that cause proliferation of hepatocyte smooth ER and thus increase hepatic glucuronyl transferase activity

A

Barbiturates, antihistamines, anticonvulsants

This increases conjugation of bilirubin to glucuronic acid

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9
Q

The ___ is the only organ in which the complete urea (Krebs) cycle is expressed

A

Liver.

This occurs in the mitochondria and cytosol of hepatocytes

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10
Q

Why is ammonia metabolism in the liver so important?

A

Otherwise it accumulates in systemic circulation, can cross the BBB and is toxic to the CNS

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11
Q

The ___ membrane of cholangiocytes expresses GGT

A

Apical

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12
Q

What are the 3 buffers to neutralise acid (H+) in the renal system, and where does each process predominately occur?

A

Ammonia (NH3 + H+ -> NH4): prox + distal tubules
Bicarb (HCO3- + H+ -> H2CO3 -> H2O + CO2): prox tubules
Dibasic phosphate (H(PO4)2- + H+ -> H2(PO4)-): distal tubules + collecting duct

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13
Q

What is an annular pancreas?

A

Developmental malformation where head of pancreas ‘wraps around’ duodenum forming a ring and increasing risk of duodenal obstruction

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14
Q

What is the first enzyme activated in acute pancreatitis?

A

Trypsin

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15
Q

What is the mechanism of acute pancreatitis secondary to alcohol?

A

Alcohol stimulates contraction of Sphincter of Oddi, blocking off pancreatic duct

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16
Q

What is the mechanism of hypocalcaemia in pancreatitis?

A

Fat necrosis of peripancreatic fat -> saponification (consumes calcium).

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17
Q

What are the fat-soluble vitamins?

A

A, D, E, K

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18
Q

What is the pathophysiology of raised ALP in cholecystitis (not due to duct obstruction)?

A

Epithelium lining gallbladder produce ALP -> when damaged (ischaemic/ inflammation) then more ALP is released into circulation

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19
Q

What is a porcelain gallbladder?

A

(Dystrophic) calcification of gallbladder wall secondary to chronic cholecystitis. It will show up as radio-opaque outline of gallbladder; Risk factor for cholangiocarcinoma

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20
Q

The brush border of intestinal epithelium is endowed with what substance?

A

Dense glycocalyx

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21
Q

What are the 3 salivary glands?

A

Parotid, submandibular and sublingual glands
Overall they supply 1000-1500mL saliva/ day

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22
Q

The saliva contains __ and ___ , which act as protective organic constituents

A

IgA and lysozyme
Saliva has 3 main functions
- digestion (esp starch): e.g. a-amylase
- protection: e.g. IgA, lysozyme + neutralize gastric acid (oral pH ~7.0)
- lubrication: e.g. mucin

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23
Q

Saliva is rich in which ions?

A

K+, bicarb (in exchange for Na, Cl)
It is a hypotonic solution

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24
Q

The [PNS/ SNS] is the most prominent control of salivary secretion

A

PNS
PNS is activated by sight/ smell/ thought of food and chewing. Acts via ACh at otic and submandibular ganglions
SNS slightly modifies saliva composition (more proteinaceous)

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25
Q

List the 4 main cell types in a gastric body/ fundus gland and what each secretes

A
  1. Surface mucous cells - mucus, trefoil peptide, bicarbonate
  2. Parietal cells - hydrochloric acid, intrinsic factor
  3. Enterochromaffin-like (ECL) cells - histamine, motilin
  4. Chief cells - pepsinogen, gastric lipase
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26
Q

Gastric hydrochloric acid sterilizes the meal and begins the hydrolysis process, especially of what dietary component?

A

Protein

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27
Q

Somatostatin inhibits which gastric cells?

A

G cells (in antrum), ECL cells (in gastric mucosa) and parietal cells (gastric mucosa)

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28
Q

List the 3 agonists for parietal cell acid secretion, the Rs they act on and the 2nd messengers they act through

A

Gastrin (CCK-B receptor) via Ca2+/ PLC
ACh (M3-R) via Ca2+/ PLC
Histamine (H2-R) via cAMP/ AC
All act on basolateral membrane, and ultimately increase apical H+/K+ pump. These act synergistically (greater than additive effect)

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29
Q

Pancreatic secretion is stimulated by ____ (via [2nd messenger]) and ____ (via [2nd messenger])

A

Secretin (via cAMP) and CCK (via PLC)

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30
Q

What are the nutritionally essential amino acids?

A

Valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, arginine, lysine, histidine

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31
Q

What are the stages of mitosis?

A

1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
5) Cytokinesis

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32
Q

Define the building blocks of RNA and DNA

A

Nucleoside = sugar (ribose or 2-deoxyribose) + N-containing base

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33
Q

The Na-K ATPase moves __ Na+ IN/OUT of the cell for every __ K+ IN/OUT of the cel

A

3 Na+ OUT for 2 K+ IN

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34
Q

Define osmolarity and osmolality

A

Osmolarity = number of osmoles per litre of solution
Osmolality = number of osmoles per kg of solvent

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35
Q

What is the isohydric principle?

A

All buffer pairs in a homogenous solution are in equilibrium with the same [H+]

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36
Q

What percentage of body is water?

A

60%
Approx 1/3rd is extra-cellular and 2/3rd intracellular
(~18% protein, 15% fat, 7% minerals in average young adult male)

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37
Q

True or false: bile is the only route by which the body can dispose of cholesterol

A

True

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38
Q

Bile acids are synthesised from ___ and secreted into bile conjugated to ___ or ___

A

Cholesterol
Glycine or taurine

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39
Q

What are the 4 bile acids, and where are each ‘produced’

A

Cholic acid & chenodeoxycholic acid from liver
Deoxycholic acid and lithocholic produced in intestine by bacterial conversion

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40
Q

CCK is primarily produced in ___. List its main actions (4)

A

I cells of the small intestine mucosa
Actions
- Pancreatic juice secretion (enzyme-rich)
- Gallbladder contraction
- Sphincter of Oddi relaxation
Also trophic effect on pancreas, inhibit gastric emptying, enterokinase synthesis, ?SI/colonic motility

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41
Q

In the GI system, secretory fluxes of fluid are largely driven by active transport of __ ions into the lumen

A

Chloride

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42
Q

98% of fluid in the GIT is reabsorbed. The majority of reabsorption occurs in which part?

A

Jejunum

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43
Q

What is the pH of each of the following fluids: saliva, gastric juice, duodenum, pancreatic juice, bile
Approximately what volume of each is produced daily?

A

Saliva: ~7.0. 1-1.5L
Gastric juice: ~3.0; 2.5L
Duodenum: 6-7.0, 1L
Pancreatic juice; ~8.0. 1.5L
Bile: 7-8.0. 500mL

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44
Q

Where is the ‘Vomiting centre’ located?

A

In the reticular formation of the medulla

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45
Q

Where is the chemoreceptor trigger zone (CTZ) located?

A

Area postrema on the lateral walls of the 4th ventricle. Has D2 and 5HT3-Rs (this explains MoA of common antiemetics - ondansetron is a 5H3T-R antagonist, and chlorpromazine/ haloperidol are D2-antagonists)

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46
Q

Intestinal __ make the greatest contribution to increased surface area

A

Microvilli

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47
Q

List key hormones involved in gastric secretions, the cells they are produced by and location of these

A

Gastrin - G cells (gastric antrum)
Somatostatin - D cells (gastric antrum and pancreatic islets)
Secretin - S cells (proximal SI)
CCK - I cells (proximal SI)
GIP - K cells (proximal SI)
VIP - enteric neurons

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48
Q

Conduction velocity is increased by ___ and ___

A

Greater neuron diameter + myelination

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49
Q

Acidosis, hypotension and hypoxia cause cerebral [vasodilation/vasoconstriction]

A

VasoDILATION

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50
Q

What is normal intracranial pressure?

A

0-10mmHg

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51
Q

Catecholamine formation is usually by hydroxylation and decarboxylation of which amino acid?

A

Tyrosine

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52
Q

Where does noradrenaline synthesis occur?

A

In intracellular synaptic vesicles
(most other small-molecule transmitters are synthesised in the cytosol)

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53
Q

The adrenal cortex releases which hormones? The medulla? Which zones does each come from

A

Cortex - steroid hormones
- Glucocorticoids - zona fascicularis
- Mineralocorticoids - zona glomerulosa
- Androgens - zone reticularis
Medulla (chromaffin cells) - catecholamines (adrenaline, noradrenaline, dopamine)

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54
Q

ACTH originates from the ___

A

Anterior pituitary

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55
Q

Denser granules are found in adrenal medulla cells secreting adrenaline or [nor]adrenaline?

A

noradrenaline

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56
Q

What are the 3 zones of the adrenal cortex?

A

Zona glomerulosa (aldosterone-producing), zona fasciculate (cortical/ proges), zone retucularis

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57
Q

List common drugs/ classes that stimulate ADH release (min 5)

A

Anti-convulsants (carbamazepine, phenytoin, valproate)
Analgesia (morphine, duloxetine, pregabalin)
Barbiturates (phenobarbital)
Anti-depressants & tricyclics (citalopram, venlafaxine, amitriptyline)
Anti-psychotics
Cytotoxics & chemo drugs
Nicotine
Chlorpropamide

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58
Q

True of false: CO2 is more soluble in CSF than H+

A

True
It is rapidly converted to H2CO3 in the CSF

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59
Q

What is the normal tidal volume and physiological dead space volume?

A

Tidal volume - 500mL
Physiological dead space - 150mL

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60
Q

List 3 examples of transcellular water

A

Aqueous humor, CSF, synovial fluid
(water that has been processed by cells into special compartments)

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61
Q

Water content of fat is (HIGHER/ LOWER) than that of muscle

A

Lower
(% water of total body weight is inversely proportional with % body fat)

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62
Q

What is the most important buffer?

A

Bicarbonate

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63
Q

Which buffer is more effective at physiological pH - bicarbonate vs phosphate?

A

Phosphate (pK 6.8 compared to bicarbonate 6.1)

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64
Q

Describe the water/ ion permeability of the descending & ascending limbs of the loop of Henle

A

Thin Descending - water permeable
Thin ascending - water impermeable, ion permeable
Thick ascending - water impermeable, active ion transport

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65
Q

In the nephron, aquaporin-1 and aquaporin-2 are predominately located in which parts respectively?

A

Aquaporin-1: proximal convoluted tubule+ descending loop of henle
Aquaporin-2: collecting duct (ADH-responsive)

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66
Q

Sodium is actively transported out of all segments of the nephron except the ___

A

Descending thin loop of Henle

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66
Q

Sodium is actively transported out of all segments of the nephron except the ___

A

Descending thin loop of Henle

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67
Q

What is the action of aldosterone?

A

Acts on collecting duct to increase expression of ENaC, resulting in water & thus Na+ reabsorption

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68
Q

What is the action of ADH?

A

Acts on distal convoluted tubules & collecting duct to increase expression of aquaporin-2, resulting in water reabsorption

69
Q

Loop diuretics inhibit ___
Thiazide diuretics inhibit ___

A

Loop - Na-K-2Cl cotransporter in the thick limb of ascending loop of Henle
Thiazide - Na-Cl cotransporter in distal convoluted tubule

70
Q

What deficit is present in Liddle’s syndrome?

A

Mutation of the ß-subunit of ENaC, making it constitutively active & causing excessive Na+ retention

71
Q

At what bladder volume do people typically experience the urge to void?

A

~400mL

72
Q

Regarding brainstem regulation of voiding reflex, which areas are facilitatory & inhibitory?

A

Facilitatory - pontine, posterior hypothalamus
Inhibitory - midbrain

73
Q

Vasopressin ADH) receptors are in which class?

A

G-protein coupled receptors

74
Q

Alcohol (decreases/ increases) vasopressin secretion

A

Decreases

75
Q

The (low/ high) pressure receptors are the primary mediators f volume effects on vasopressin secretion

A

Low

76
Q

___ is the most important determinant of ECF volume

A

Na+

77
Q

True or false: renin is a glycoprotein and aspartyl protease

A

True

78
Q

Angiotensinogen levels are increased by _____

A

Glucocorticoids, oestrogen, thyroid hormones, cytokines and angiotensin II

79
Q

ACE is responsible for which major 2 enzymatic processes?

A

Conversion of angiotensin I -> II
Inactivation of bradykinin

80
Q

(Angiotensin II vs noradrenaline) has more potent vasoconstriction action

A

Angiotensin II

81
Q

True or false: angiotensin II penetrates the blood-brain barrier

A

False
It acts on the circumventricular organs instead

82
Q

EPO has a half life of ___ and the principal site of inactivation is the ____

A

5hrs
Liver

83
Q

EPO is predominately produced in which 2 organs?

A

Kidney (85%) & liver (15%)

Also some production in the brain, uterus & oviducts

84
Q

The seminal vesicles produce ~____% of seminal fluid

A

60-70%

85
Q

Which 3 hormones are produced by the corpus luteum?

A

Oestrogen, inhibin, progesterone

86
Q

Which hormone is primarily responsible for ovulation?

A

LH (peak ~day 14 in response to ‘critical level’ of oestrogen)

87
Q

During the luteal phase of the menstrual cycle, progesterone inhibits ___ and inhibin inhibits ___

A

Progesterone - GnRH
Inhibin - FSH
(negative feedback mechanisms)

88
Q

Regarding breast enlargement / development during pregnancy: oestrogen is important for ___ growth, progesterone for ___ growth

A

Oestrogen - ductal growth
Progesterone - lobule growth

89
Q

The nicotinic ACh-R activates ___ whereas the muscarinic ACh-R activates ___

A

Nicotinic - cation channel (Na+, K+)
Muscarinic - GPCR (Gi -> AC; Gq -> PLC)

90
Q

Sweat glands contain which type of ACh receptors?

A

Muscarinic

91
Q

Sympathetic pre-ganglionic fibres synapse with ___ cells in the adrenal ___

A

Chromaffin cells
Adrenal medulla

92
Q

Alpha 2-ARs are mostly (pre/post) synaptic and inhibit release of ____

A

Pre-synaptic
Noradrenaline

93
Q

ß2-ARs trigger skeletal muscle vaso____

A

Vasodilation

94
Q

What are the 3 types of neurotransmitters and examples of each?

A

1) Amino acid derivatives: glutamate, aspartate (excitatory), GABA, glycine (inhibitory)
2) Peptides: vasopressin, somatostatin, neurotensin
3) Monoamines: NA, DA, 5-HT

95
Q

Compare NMDA & GABA-Rs

A

NMDA - Na+ channel, excitatory; binds glutamate, glycine (allosteric modulator)
GABA - Cl+ channel, inhibitory; binds GABA, BZDs, barbiturates, EtOH

96
Q

How many pairs of spinal nerves are there?

A

31

97
Q

The Pre-ganglionic cell bodies of PNS/ SNS are located in the ____ of spinal cord

A

Intermediolateral column (IML)

98
Q

Neurons in the _____ (nucleus) innervate the SA & AV nodes

A

Nucleus ambiguus

99
Q

What is the daily caloric intake requirement?

A

2000 kcal/day for basal needs + 500-2500 kcal/day to meet energy demands

100
Q

___ is the proenzyme of pepsin and is activated by ___

A

Pepsinogen
Gastric acid

Pepsin has optimal action in pH 1.6-3.2, and therefore does not function when gastric contents are mixed with alkaline pancreatic juices

101
Q

__-__% of ingested calcium is absorbed

A

30-80%

102
Q

Which form of iron is absorbable and which binds to transferrin?

A

Ferrous (Fe2+) form is absorbable (this is not the common form of dietary iron)
Ferric (Fe3+) binds to transferrin

103
Q

Regarding renal blood flow, list a chemical that a) causes vasoconstriction, b) vasodilation and c) increases cortical flow but decreases medullary flow

A

a) noradrenaline (affects interlobular artery/ afferent arteriole) OR angiotensin II (afferent & efferent arteriolar vasoconstriction)
b) dopamine and ACh
c) prostaglandins

104
Q

What are the 2 types of diuresis (renal) and give an example

A

Osmotic (non-absorbable filtrate retains water in lumen) e.g. hyperglycaemia
Water (decreases ADH & plasma osmolality) e.g. high volume H2O intake

105
Q

Compare the action of aldosterone & ADH

A

Aldosterone - increases number of ENaC in collecting ducts, increasing Na+ (and thus H2O) reabsorption
ADH - increases expression of aquaporin 2 in collecting duct

106
Q

List 3 hormones that cause Na/H2O retention and 3 that cause natriuresis

A

Retention
- Aldosterone
- ADH
- Angiotensin II
Natriuresis
- ANP
- PGE2
- Ouabain

107
Q

What type of diuretics can cause hypokalaemia?

A

Loop & thiazide

108
Q

Alcohol with ____ (increase/ decrease) ADH levels

A

Decrease

109
Q

What is the RAAS sequence (include location of action & enzymes)

A

(liver produces) angiotensinogen -> (via renin) angiotensin I -> (via ACE in lung) angiotensin II -> (acts on adrenal cortex) aldosterone

110
Q

What types of proteins are ACE and EPO, respectively?

A

ACE - dipeptidyl carboxypeptidase
EPO - glycoprotein

111
Q

Prostacyclin is produced by ____ and causes vaso____, _____ and (promotes/ inhibits) platelet aggregation.
Thromboxane A2 is produced by ____ and causes vaso___ and (promotes/ inhibits) platelet aggregation

A

Prostacyclin (PGI2) - Vascular endothelium and smooth muscle cells in the blood
It causes vasodilation and renin activation (direct via JGA or indirect via reduced BP) and INHIBITS platelet aggregation

TXA2 - platelets; vasoconstriction, PROMOTES platelet aggregation

112
Q

Group these substances into vasoconstrictors & vasodilators:
- lactate
- prostacyclin
- TXA2
- histamine
- platelet serotonin
- AVP
- ANP
- Endothelin-1

A

Vasoconstriction:
- TXA2
- platelet serotonin
- Endothelin 1
- AVP

Vasodilation:
- lactate
- prostacyclin
- histamine
- ANP

113
Q

Endothelin-1 is a potent vaso____, acting more on (veins/ arterioles)

A

vasoconstrictor
Veins > arterioles
(It also has a particular effect on coronary artery vasoconstriction)

114
Q

Sympathectomy will cause vaso_____

A

Dilation

115
Q

What are the 4 locations of baroreceptors, and what does each monitor?

A

(1&2) Carotid sinus & aortic arch → monitor arterial circulation
(3) RA wall → monitor venous return
(4) LA wall → monitor pulmonary circulation

116
Q

What is the O2 extraction rate in the coronary circulation at rest and during exercise?

A

Rest - 70%
Exercise - 100%

117
Q

Noradrenaline overall acts to cause vaso___ of the coronary arterioles

A

Vasodilation
Acts on both alpha-ARs (constriction) and ß-ARs (dilation), but also causes increased HR, CO & SBP, triggering release of other vasodilator metabolites

(Note: if patient ß-blocked, will only act on alpha-ARs and cause life-threatening vasoconstriction)

118
Q

What 5 factors regulate cerebral blood flow?

A

(1) Mean venous & (2) arterial pressures
(3) ICP
(4) Local cerebral vasoconstriction/ dilation
(5) Blood viscosity

119
Q

_____ metabolism always remains constant regardless of blood flow

A

Cerebral

120
Q

What is the percentage of oxygenated blood along the route for fetal blood flow ?

A

80% in umbilical vein -> 67% in IVC via ductus venosus -> 65% in LA -> 65% to brain / 60% trunk/lower body (further ‘diluted’ by deoxy blood from RV shunted via ductus arteriosus)
Portal/ systemic venous blood ~26%

121
Q

Where are the SA and AV nodes located respectively?

A

SA - RA wall below SVC opening
AV - posterior interatrial septum, behind tricuspid valve

122
Q

What are the average volumes for EDV, SV, ESV & EF

A

EDV = 130mL
SV = 70-90mL
ESV = EDS - SV = ~50mL
EF = SV/EDV = ~65%

123
Q

Increased contractility shifts the Frank Starling curve ___

A

Up & Left

124
Q

____ is the most potent vasoconstrictor

A

Angiotensin II

125
Q

Dopamine acts on which receptors? (broad classes)

A

Alpha & ß1/ß2 adrenergic + dopaminergic

126
Q

90% of re-entry circuits in atrial flutter are ____ (direction)

A

Anticlockwise

127
Q

Oxygen vaso____ the pulmonary vascular tree via ___

A

Vasodilates via NO

128
Q

Prostaglandins cause vaso____ of the ductus arteriosus

A

Vasodilation

Therefore withdrawal of PGs is needed for the ductus to close (together with increased bradykinin from the lung)

129
Q

What is the threshold potential of cardiac pacemaker cells?

A

-40mV

130
Q

What is the resting potential of ventricular myocytes?

A

-85mV

131
Q

The AV node delays transmission of action potential by ____

A

0.1s
(Slows impulse to ~0.05m/s)

132
Q

According to the law of Laplace, a dilated ventricle needs ____ (greater/ less) tension to overcome a given pressure

A

Greater
T = Pr/w, where T = tension, P = transmural P, r = radius, w = wall thickness
Dilated ventricle = wider radius

Another way to arrange equation for application to alveolus is P = (2 x wall thickness x surface tension)/radius

133
Q

Phenylephrine is a(n) ______ agonist. It (increases/ decreases)

A

Alpha-adrenergic agonist
It increases TPR & BP

134
Q

The rate of gas exchange is dependent on which 3 main variables?

A

Surface area
Membrane thickness
Diffusion coefficient

135
Q

Only _____% of O2 dissolved in blood - the rest is carried on Hb

A

1.5%

136
Q

Haemoglobin/ O2 displays _____ allosteric binding

A

Positive

137
Q

The Bohr effect states that the affinity of Hb for O2 is _____ in the presence of CO2/H+

A

Reduced

138
Q

CO2 is mostly transported as ___ in the blood

A

HCO3- (~90% of arterial CO2; ~70% of this enters plasma)
- Arterial: other 5% CO2 dissolved in plasma, 5% as carbamino compounds
- Venous: 60% HCO3-, 30% carbamino compounds, 10% dissolved

CO2 + H2O -> (carbonic anhydrase) H+ + HCO3-

139
Q

What are normal tidal & residual volumes?

A

Tidal - 500mL (5-7mL/kg)
Residual - 1200mL

140
Q

What is vital capacity (lung volumes)?

A

The expiratory + inspiratory reserve volume (maximum breathing capacity: everything except the residual volume)

141
Q

Which measure of lung volumes is a good indicator of emphysema?

A

Functional residual capacity

142
Q

Which muscles are responsible for active expiration?

A

Internal intercostals + anterior abdominal muscles

Compared to quiet/ normal expiration, which is passive recoil of the chest wall

143
Q

Surfactant is produced by ______

A

Type II pneumocytes

144
Q

In the pulmonary circulation hypoxia causes vaso_____ and in the systemic circulation it causes vaso_____

A

Pulmonary - vasoconstriction
Systemic - vasodilation

The same is true for hypercapnia

145
Q

What is respiratory minute volume?

A

Tidal volume x resp rate

146
Q

What is the basal consumption rate of O2 and production rate of CO2?

A

O2 - 250mL/min consumed
CO2 - 200mL/min produced

147
Q

The ____ configuration of Hb has decreased affinity for O2 binding

A

‘T’ (tense) configuration

Compare to ‘R’ (relaxed) configuration - increased affinity

148
Q

Carbonic anhydrase is present in RBC or plasma?

A

RBC
Rapidly converts CO2 + H2O -> H2CO3

149
Q

Administration of 100% O2 has (MORE/LESS) effect on PaO2 as shunt fraction increases because ____

A

Less
Only improves shunted alveoli
Hb already fully saturated in adequate ventilated alveoli

150
Q

What are the features of Virchow’s triad?

A

1 - vessel wall injury
2 - altered blood flow (stasis)
3 - hypercoagulability

151
Q

Clopidogrel (irreversibly/ reversibly) and ticagrelor (irreversibly/ reversibly) inhibit ____

A

Clopidogrel irreversibly; ticagrelor reversibly inhibit P2Y12

152
Q

___ are the most abundant white blood cell line in the blood

A

Granulocytes (polymorphonuclear leukocytes)

153
Q

In platelets, ADP, serotonin and calcium are found in ___ granules, whilst P-selectin, fibrinogen and PDGF are found in ____ granules

A

Dense delta 𝛅 granules
Alpha 𝛂 granules

154
Q

What is the co-stimulatory signal?

A

CD4-R binds MHCII + CD28 (T cell) binds CD80/B7 (APC)

155
Q

An ____ environment is needed to calcify bone, whereas an ____ environment is needed to break it down (acidic/alkaline)

A

Alkaline
Acidic

156
Q

True or false: bile acids are amphipathic

A

True
They have both hydrophobic & hydrophilic parts

157
Q

___ gallstones are radiolucent, whereas ___ gallstones are radio-opaque

A

Cholesterol - radiolucent
Calcium bilirubinate - radio-opaque

158
Q

The renal blood flow is ~___% of cardiac output

A

25%

1.2-1.3L/min

159
Q

The glomerular endothelium permits passive passage of _____ substances (3 features). The pores are approximately what size?

A

Neutral, cationic, up to 4nm
70-90nm

160
Q

The juxtaglomerular apparatus is made up of ____ cells in the ___, and ___ cells in the ____

A

Granular cells in the afferent arteriole
Macula densa cells in the distal thick ascending loop of Henle and proximal DCT

161
Q

In the collecting duct of the renal tubule, there are more ___ cells than ___ cells

A

P (principal) cells [Na reabsorption] > I (intercalated) cells [acid secretion]

162
Q

True or false: The ascending loop of Henle is permeable to water

A

False
It is impermeable (both thin & thick portions)
The descending loop is permeable to water and responsible for concentration of filtrate
Thin ascending - permeable to ions
Thick ascending - active transport of ions

163
Q

The respiratory system is a (HIGH/LOW) pressure & resistance system

A

Low
Pulmonary artery pressure ~25/10mmHg

164
Q

Wherea re the J receptors located in the pulmonary system?

A

The pulmonary interstitium

165
Q

Androgen & thyroid hormones (INCREASE/DECREASE) the levels of 2,3-DPG

A

Increase

166
Q

Which hormones are secreted in the posterior pituitary? They are made in the ____ (specific)

A

ADH & oxytocin
Made in hypothalamus, in the supra-optic & paraventricular nuclei

167
Q

Which hormones are made/ secreted in the anterior pituitary?

A

ACTH, PRL, FSH, LH, GH, TSH

168
Q

What percentage of thyroid hormones are protein bound, and to which proteins

A

70% thyroxin-binding protein (TBG)
15% albumin
10% transthyretin (TTR)

169
Q

What is resting neuronal membrane potential, and which ion is the main determinant?

A

-70mV
K+

170
Q

Ouabain (promotes/ inhibits) the Na-K-ATPase

A

Inhibits

171
Q

Melaena will be seen macroscopically when ≥____mL blood are lost daily in the stool

A

≥100mL

GSSE (3 decks)

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