Physiology Flashcards
(136 cards)
1
Q
O2 haem dissociation curve right shift cause
A
Cadet face right:
CO2 (high)
Acidosis
(2,3)DPG (high)
Exercise
Temperature (high)
2
Q
Haldane effect
A
Left shift
3
Q
Bohr effect
A
Right shift : at a given PO2, the oxygen is released more easily
4
Q
Furosemide place of action
A
ascending loop of henle
5
Q
Thiazide place of action
A
distal tubule and collecting segment
6
Q
Spirnolactone place of action
A
Collecting tubule
7
Q
Endocrine response to surgery
A
Increased ACTH and cortisol
Aldosterone
Vasopressin
8
Q
Result of increased cortisol
A
Increased glucose
Protein breakdown
9
Q
Lung volumes
A
Vital capacity (max inspiration and expiration)
Tidal volume (normal cycle)
10
Q
A gamma fibres convey
A
Motor proprioception
11
Q
A beta fibres convey
A
Touch and pressure
12
Q
B fibres convey
A
autonomic NS
13
Q
C fibres convey
A
mechanothermal stimuli
14
Q
Optic tract lesions and visual field defects
A
15
Q
Examples of oncogenes
A
Growth factors e.g. Sis
Transcription factors e.g. Myc
Receptor tyrosine kinase e.g. RET
Cytoplasmic tyrosine kinase e.g. Src
Regulatory GTPases e.g. Ras
16
Q
Examples of tumour suppressor genes
A
BRCA 1 and 2
p53
17
Q
Gastric acid secretion phases
A
- Cephalic 30%
- gastric 60%
- intestinal 10%
18
Q
Cephalic phase of gastric acid secretion
A
Smell/taste
Vagal stimulation causing gastrin release from G cells
19
Q
Gastric phase of gastric secretion
A
Stomach distension causes gastrin release
20
Q
Intestinal phase of gastric acid secretion
A
High acidity inhibits CCK and secretin secretion
21
Q
Factors inducing gastric secretion
A
Vagal activity
Gastrin
Histamine (from enterochromaffin cells)
22
Q
Factors inhibiting gastric secretion
A
Secretin
Cholecystikinin
Somatostatin
23
Q
Cells responsible for gastric acid release
A
Parietal cells
24
Q
Which cells produce gastrin
A
G cells in antrum of stomach
25
Which cells produce CCK
I cells in upper intestine
26
Which cells produce secretin
S cells in upper intestine
27
Secretin vs CCK
Secretin: stimulates water and bicarb release to neutralise chyme acidity
CCK: stimulates enzymes release
28
Which cells produce VIP
Small intestine/ pancreas
29
Which cells produce somatostatin
Delta cells of pancreas and stomach
30
Which cells produce intrinsic factor
parietal cells
31
Obstructive lung disease pulmonary function test
FEV1 reduced
FVC normal
FEV1/FVC \<70%
32
Restrictive lung disease pulmonary function test
FEV1 normal
FVC sig reduced
FEV1/FVC \>70%
33
Brainstem respiratory centres
Medullary resp centre
Apneustic centre
Pneumotaxis centre
34
Medullary resp centre
Has both inspiratory and expiratory neurons
Depressed by opiates
35
Apneustic centre
Lower pons
Stimulates inspiration
36
Pneumotaxis centre
Upper pons
Inhibits inspiration (apneustic centre)
37
Where are peripheral chemoreceptors located
Birfurcation of carotid arteries
Arch of aorta
38
What do the peripheral chemoreceptors respond to
Drop in O2,
Increased CO2, H+
(In arterial blood)
39
Where are central chemoreceptors located
Medulla
40
What do central chemoreceptors respond to
Increased H+ in brain
41
Stages of wound healing
Haemostasis
Inflammation: Day 1-5
Regeneration: Day 7 to 56
Remodelling: 6 weeks to 1 year
42
Inflammation stage of wound healing
Neutrophils migrate
Growth factors: eg VEGF
Fibroblasts migrate
Macrophage and fibroblast matrix regeneration and clot substitution
43
Regeneration stage of wound healing
Growth factors stimulate fibroblasts to produce a collagen network
Angiogenesis occurs
Wound resembles granulation tissue
44
Remodelling stage of wound healing
Fibroblasts become myofibroblasts (tissue contraction)
Collagen remodelled
Microvessels regress leaving a pale scar
45
Drugs that impair wound healing
NSAIDs
Steroids
46
Stages of bone healing
47
Which hormones increase in response to surgery
Pituitary : GH, prolactin, ACTH
Adrenal: cortisol, aldosterone
Pancreas: glucagon
48
Which hormones reduce in level in response to stress
Insulin
Testosterone
Oestrogen
49
Phagocytosis stages
Stage 1: opsonisation (antibodies on surface of cells)
Stage 2: Adhesion to cell surface
Stage 3: Phagocytic vacuole formation
Stage 4: Lysosome fuse with vacuole and degrade content
50
Baroreceptor location
Carotid sinus
Arch of aorta
51
Baroreceptor refelx
Stimulated by arterial stretch
Carotid sinus afferent via CN9
Aortic arch afferent vis CN10
-\> Increase PSN to SA node
52
Brainbridge reflex
Increased blood volume in right atrium causes an increase in HR (opposite of baroreceptor reflex)
(eg rapid transfusion leads to tachycardia)
53
What stimulates prolactin release
TRH
54
What inhibits prolactin release
Dopamine
55
Centre for thermoregulation
Hypothalamus
56
Which electrolyte's defficiency leads to calcium deficiency
Magnesium
(required for PTH secretion/ decreased mg makes cells hyperexcitable)
57
TLCO def
Total carbon monoxide transfer factor
Rate of diffusion of a gas from alveoli into blood
58
Conditions with increased TLCO
asthma
haemorrhage
left-to-right shunts
polycythaemia
59
Water reabsorption site in GI tract
Majority absorbed in jejunum
60
Water reabsorption site in renal tubule
2/3 in proximal convoluted tubule
61
Drug causes of SIADH
Carbomezapine
SSRI
Sulfonylurea: eg gliclazide
TCA: eg amitriptyline
62
Normal intracranial pressure range
7 - 15 mmHg
Can accommodate up to 24 before sx appear
63
Metaplasia
Abnormal change in the nature of the tissue
eg Barrets oesophagus
64
Dysplasia
Replacement of one type of tissue with another
65
Heterotopia
the tissue type that is found in the abnormal location is present there from birth and does not migrate to that site subsequently or arise as a result of metaplasia
eg Meckels diverticulum with lined with gastric tissue
66
How to measure functional residual capacity, residual volume and the total lung capacity
Cannot be measured by spirometry
Needs helium dilution measurement
67
Interphase stages
68
Mitosis and cytokinesis stages
Prophase: nuclear membrane breaks down
Metaphase: chromosomes aligned at the centre
Anaphase: chromosomes pulled opposite direction
Telophase: Nuclear membrane forms
Cytokinesis: cytoplasm divides
69
What is absorbed in terminal ilieum
Bile salts
B12
70
What is absorbed in duodenum
Calcium
Iron (and upper jejunum)
71
Factors that increase 2,3 DPG
Chronic anaemia
High altitude
72
Role of vasopressin
Aka ADH
Increased permeability to water in the distal tubule by insertion of aquaporin channels in apical membrane
73
Fluid proportions
65% intracellular
35% extracellular:
- 5% plasma
- 24% interstitial
- 3% transcelullar
74
How to measure anatomical dead space
Fowlers method: Inhale 100% oxygen to fill up the dead space with O2, measure the nitrogen concentration in exhale: this nitrogen has come from alveoli and not the conducting zone so the difference is representing dead space
75
Which acute phase proteins reduce in level in response to stress
Albumin
Transferrin
76
Hassals corpuscle
thymus
77
Chovsek vs trosseau's sign
Both hypocalcaemia
Chovstek: tap on facial nerve
Trosseau: BP cuff makes wrist flexion
78
Reasboprtion in kidneys
Majority in proximal convuluted tubule
79
Where in kidneys do NSAIDs work
Afferent arteriole
80
Where in kidneys do ACEi work
Efferent arteriole
81
Where is chemical trigger zone situated
Outside BBB
82
Effects of Low mg on Ca
Low mg inhibits PTH-\> reduces Ca
83
Effect of aldosterone on K
Reduced serum K
| (primary hyperaldosteronism, aka conns)
84
Cardiogenic shock physiological changes
SVR
HR
BP
CO
SVR up
HR up
BP low
CO low
85
Hypovolaemic shock physiological changes
SVR
HR
BP
CO
SVR high
HR high
BP low
CO low
86
Septic shock physiological changes
SVR
HR
BP
CO
SVR low
HR high
BP low
CO low
87
Neurological shock
SVR
HR
BP
CO
HR low
BP low
CO normal
88
Opiates receptors
Gamma: analgesia + antidepressant
Kappa: analgesia + dissociative state
Mu: analgesia, reduce gut mobility, miosis
89
ECG changes in hyper K
Tall t wave
No P wave
Broad ventricular complex
90
Effect of Conn's on K
Increased aldosterone
Sodium retension and loss of K
91
Effect of ACEi on K
Reduced aldosterone -\> low K
92
Light's criteria for transudate vs exudate
It is exudate if one of the following is true:
Effusion Protein:serum protein \>0.5
Effusion LDH:Serum LDH \>0.6
Effusion LDH \>2/3 of upper level of range of serum LDH
93
Causes of exudate
Infection
Malignancy
Inflammation
94
Causes of transudate
Cardiac failure
Nephrotic syndrome
Atelectasis
95
Where is EPO produced
In adults, peritubular fibroblasts of renal cortex
In infants, hepatocytes
96
Where in cell cycle does p53 act
Stops cells from entering S phase
'gaurdian of genome'
97
Apoptosis vs necrosis energy
A: energy dependent
N: not energy dependent
98
Apoptosis vs necrosis regulation
A: regulated
N: not regulated
99
Apoptosis vs necrosis cell integrity
A: intact
N: breakdown
100
Menstrual cycle phases
Menstruation
Follicular phase
Luteal phase
101
Spontaneous muscle contraction at what calcium level
At HYPO calcaemia
102
How does air embolus lead to death
Causes right sided ventricular obstruction, circulatory collapse and death
103
Primary and secondary stimuli of carotid body receptors
Primary:drop in PaO2
Secondary: rise in PaCO2 or fall in pH
Stimulates ventilation
104
Saliva composition
Water 99.5%
Enzymes: lipase, amylase
Antimicrobial: IgA antibody, lysozomes
105
Ferritin function
Binds iron and stores it within the cells
106
Transferrin function
Transports iron in blood
107
Iron storage in body
60-70% within haemoglobin and myoglobin
Rest mostly bound to ferrtin intracellularly
some as Haemosiderin
108
What is haemosiderin
Intracellular iron storing complex, made off ferritin, denatured ferritin and other materials
(commonly found within macrophages in areas where haemorrrahge has occured)
109
Metabolic response to surgery
Initial slowing down 'Ebb'
Followed by speeding up 'flow'
110
Events during Ebb phase
Reduced cardiac output
Reduced metabolic rate
Reduced glucose tolerance
Lasts up to 24hrs
111
Events during flow phase
Increased CO, metabolic rate and glucose tolerance
Muscle catabolism and negative nitrogen balance
Lasts up to weeks post Ebb phase
112
Changes caused by obesity to cardiovascular system
Increased blood volume -\> left ventricular dilation -\> reduced compliance of left ventricle
113
What is the most important stimulus to respiration central chemoreceptors
H+ ions don't cross BBB, whilst CO2 does.
Increased in the concentration of H ions in CSF stimulates the central chemoreceptors to fire
114
Ejection fraction formula
Stroke volume/end diastolic volume
60%
115
Starvation brain energy source
Ketone bodies from metabolising fatty acids
116
Loop of henle physiology
Descending: concentrates as water is passively reasborbed
Ascending: dilutes as sodium is actively reabsorbed
117
Anasarca
generalised oedema secondary to cardiac or liver failure (as opposed to specific site oedema)
118
Blood brain barrier location
Most areas of the brain are covered in BBB,
119
Brain blood barrier function
To avoid entry to toxins and pathogens into the CSF
120
Examples of areas not covered by BBB
Posterior pituitary (needs holes big enough to release hormones into blood)
Medial hypothalamus (hormones from anterior pituitary enter the blood through this)
Area postrema (part of brainstem responsible for picking up toxins)
121
BBB structure
Astrocytes surround tight junctions of the capillaries
122
The normal range for anion gap
10 - 18 mmHg
123
Causes of raised anion gap
Addition of either intrinsic or extrinsic acid
Lactate: shock, hypoxia
Ketones: diabetic ketoacidosis, alcohol
Urate: renal failure
Acid poisoning: salicylates, methanol
124
Causes of reduced anion gap
Low albumin
High Ca, Mg
125
Salicylate poisoning acid base disturbance
First causes stimulation od resp centre leading to resp alkalosis
Later direct acid effect of salicylate + acute renal failure causes met acidosis
126
Laplace's law
A hollow organ with a circular cross section, total circumferential wall tension depends on wall thickness, circumference of the wall and wall tension
eg a rise in ventricular pressure during ejection is due to change in heart size, a dilated heart will have impaired systolic function
127
Starlings Law
increased end-diastolic volume produces a larger stroke volume
128
Peristalsis in oesophagus
Circular muscle contracts so the food doesn't go backwards
Longitudinal muscle contracts and propels the food forward
129
Primary vs secondary peristalsis
Primary lasts 9 seconds and moves food from the oesophagus to stomach
Secondary occurs when food left in the oesophagus stimulates the stretch receptors to push it into oesophagus
130
Types of colonic peristalsis
Segmentation contractions
Antiperistaltic contractions towards ileum
Mass movements
131
GFR definition
total volume of plasma per unit time leaving the capillaries and entering bowman's capsule
132
Renal clearance
volume plasma from which a substance is removed per minute by the kidneys
133
Effect of activated vit d vs PTH on phosphate
Vit d: increases renal reabsorption
PTH: reduces renal reabsorption
134
Vit D effects
Increase Ca and PO4 (through kidney and gut)
Low level: increases osteoblastic activity
High level: increases osteoclastic activity
135
Which cells does PTH work on
Activates osteoblasts to produce a signal which leads to activation of osteoclasts
136
Mech of action of carbimazole
Inhibits thyroid peroxidase enzyme
