Principles of Physiology and Pharmacology Flashcards
1
Q
Which is the myelinating cell-type in the PNS?
A
Schwann cell
2
Q
What does excitation-contraction coupling start with?
A
Propagation of APs along sarcolemma
3
Q
Concerning body fluids and osmolality, select the incorrect statement
a) Plasma osmolality is 290mosmol/kg H2O
b) Isotonic saline has 150mmol/L of NaCl
c) 500ml of water containing 20mmol of CaCl2 has an osmolarity of 80mosmol/kg H2O
d) Normal blood has a haematocrit of 0.47 in adult males
A
500ml of water containing 20mmol of CaCl2 has an osmolarity of 80mosmol/kg H2O
4
Q
Renal clearance values…
a) For insulin are a measure of GFR
b) Greater than the GFR indicates tubular secretion
c) Less than GFR are always indicative of tubular reabsorption
d) Can be measured non-invasively
A
Greater than the GFR indicates tubular secretion
5
Q
How long is a cardiac action potential?
A
200 to 400 milliseconds
6
Q
What type of Ca channels are found at the T-tubule membrane?
A
L-type/Dihydropyridine (DHP) receptors
7
Q
What cells does omeprazole act on?
A
Parietal cells
8
Q
Where are components of Herring bodies synthesised?
A
Preoptic and paraventricular nuclei of hypothalamus
9
Q
What is the terminal cisternae?
A
The area where the sarcoplasmic reticulum on the myofibrils meet
10
Q
What is nebulin?
A
Actin-binding protein that extends from Z band along length of actin filament
Acts as template to regulate actin length
11
Q
What is titin?
A
Protein than extends Z-line to M-line
Anchors myosin to maintain central position in sarcomere
12
Q
What are the 3 functional stages of the sarcomere?
A
Resting Stage
Contracting Stage
Stretched Stage
13
Q
What type of contraction is present in the contracting stage of the sarcomere?
A
Concentric contraction
14
Q
What type of contraction is present in the stretched stage of the sarcomere?
A
Eccentric contraction
15
Q
What complex on tropomyosin blocks the head of actin?
A
Troponin
16
Q
What does Calcium bind to when released into the sarcoplasm?
A
Troponin complex (Troponin C)
17
Q
How many stages are there to muscle contraction and what they called?
A
5 stages Attachment Release Bending Force Generation Reattachment
18
Q
How does muscle relax?
A
Calcium AT into sarcoplasmic reticulum to remove from cytosol
Stops binding to troponin
19
Q
What are the 3 types of muscle fibres?
A
Slow twitch - oxidative type 1
Fast twitch - oxidative, glycolytic type 2A
Fast twitch - glycolytic type 2B
20
Q
What is the length-tension relationship in a muscle?
A
Tension a muscle can generate related no of cross bridges formed between thick and thin filaments
21
Q
What percentage of our body weight is water and what is it made up of?
A
60% water (42L) 40% of water - intracellular space (28L) (3.5L of which is blood cells) 15% is interstitial space (10.5L) 5% is plasma space (3.5L)
22
Q
What is the water content of lean tissue?
A
0.7L/kg
23
Q
How to calculate interstitial space?
A
Interstitial space = ECS - plasma volume
24
Q
How to calculate intracellular space?
A
Intracellular space = TBW - ECS
25
How would you measure plasma volume?
| What does the substance have to be like?
Something that can't cross capillaries
| Evans Blue, labelled Inulin, Albumin
26
How would you measure extracellular space?
| What does the substance have to be like?
Something that doesn't enter cell easily
| Na-24, Sucrose
27
How would you measure total body weight?
| What does the substance have to be like?
Something that distributes with all water
| H2O-8
28
What is the difference between osmolarity and osmolality?
Osmolarity - 1 osmole p/litre
| Osmolality - 1 osmole p/kg
29
What causes crystalloid osmotic pressure?
Due to small diffusable ions (e.g. Na, Cl, K in body fluid)
30
What causes oncotic osmotic pressure?
Proteins that can't cross cell membranes and displace water molecules
31
What is the main ion in plasma and what does it control?
Sodium, Blood volume
32
What is the main ion in intracellular fluid and what does it control?
Potassium, Cell volume
33
What are the 3 plasma proteins and what do they do?
Albumin - oncotic osmotic pressure, buffering of pH,
Alpha, beta, gamma globulins - haemostasis, transport, immune system
Fibringon - haemostasis
34
What is the lifespan of RBC?
120 days
35
What percentage of leucocytes is lymphocytes and what do they do?
20-40%
| Produce immunoglobins
36
What percentage of leucocytes is monocytes and what do they do?
2-8%
| Form macrophages
37
What makes up granulocytes in leucocytes and what does each do?
Neutrophils - 50-70%, phagocytosis, chemotactic
Eosinophils - 1-4%, phagocytosis, allergy
Basophils - ~0.5%, release His + heparin
38
What are platelets?
Fragments of megakaryocytes
39
What are the 3 types of negative feedback?
Neuronal
Endocrinal
Local
40
What is normalization?
Change in variable being regulated is compared against a set-point
Causes a response that tends to move variables back to the set point
41
What is amplification?
Change in variable triggers a response that causes further change in that variable
42
Where are the neuronal integrating centres for physiological control located?
Midbrain and Brain-stem
43
What are the endocrine organs (8)?
```
Hypothalamus
Pituitary
Thyroid
Parathyroid
Adrenal cortex + medulla
Pancreas
Testes
Ovaries
```
44
What are the releasing hormones of the hypothalamus?
GHRH - Growth Hormone Releasing Hormone
CRH - Corticotrophin Releasing Hormone
TRH - Thyrotrophin Releasing Hormone
GnRH - Gonadotrophin Releasing Hormone
45
What are the inhibiting hormones of the hypothalamus?
Somastostatin
| Dopamine
46
What hormones are secreted by the posterior pituitary?
Neuroendocrine
Oxytocin
ADH - anti-diuretic hormone
47
What hormones are secreted by the anterior pituitary?
```
Endocrine
GH - Growth hormone
Prolactin
FSH - Follicle Stimulating Hormone
LH - Luteinizing Hormone
TSH - Thyroid Stimulating Hormone
ACTH - Adrenocorticotrophic Hormone
```
48
What are the types of hormones?
```
Peptides
Polypeptides
Glycopeptides
AA derivatives
Steroids
```
49
What hormones have tyrosine as a derivative?
```
Thyroxine T4 (in the thyroid)
Adrenaline (adrenal medulla)
```
50
What hormones do the ovaries secrete?
Progesterone
| Estrogens
51
What type of hormones do the testes secrete?
Androgens e.g testosterone
52
What hormones does the adrenal cortex secrete?
Glucocorticoids e.g. Cortisol
| Mineralocortocoids e.g. Aldosterone
53
What hormones have their receptor location in the plasma membrane and mechanism of action?
Peptides, Proteins, Glycoproteins, Catecholamines
| Secondary messengers to change enzyme activity
54
What hormones have their receptor location in the intracellular (cyto/nucleus) and mechanism of action?
Steroids, thyroid hormones
| Alter gene transcription
55
What is a natural example of positive feedback?
Parturition - contraction of uterus to expel fetus
56
What are the 2 types of circulation?
Pulmonary circulation - in series with systemic
| Systemic circulation - mostly parallel with each other
57
How to calculate cardiac output?
Cardiac Output = Stroke Volume x Heart Rate
58
What is laminar flow?
Viscous drag at sides of tube slows fluid
| Fastest in centre
59
What is the Fahraeus-Lindquist effect?
Cells tend to become aligned in fast-moving fluid
| Axial streaming
60
What is turbulence?
Partial narrowing of artery
61
What can turbulence trigger?
Can trigger production of reactive oxygen species
| Induce proliferation and migration of vascular sm cells
62
In the left ventricle, what does the pressure oscillate between?
0-120 mmHg
63
In the right ventricle, what does the pressure oscillate between?
0-20 mmHg
64
How are electrical events in cells measured?
Intracellular - Electrode inside cell
Extracellular - Electrode outside cell
Patch Clamping - Electrode sealed to cell surface
65
What types of medical diagnostic tools use extracellular recordings?
ECG - Electrocardiogram
EMG - Electromyograph
EEG - Electroencephalogram
66
When a membrane is at rest, what ion is it more permeable to?
Potassium
67
What is the difference between permeability and conductance?
Permeability - ease with which an ion can enter a membrane, (no of open channels)
Conductance - measure of current that gets across cell membrane
68
How many subunits does a potassium channel have?
4
69
A transmembrane current can either be...?
Resistive - ion flows through channels
| Capacitative - ion approaches 1 surface of membrane and another is expelled from other side
70
What is a consequence of demyelination?
Current dissipates over a distance
71
What are heart cells connected by?
Intercalated discs
72
What are MEPPs?
Sub Threshold Minature Endplate Potentials
| small depolarisations of post-synaptic terminals caused by release of single vesicle into synaptic cleft
73
What response can MEPPs cause?
EPSP - Excitatory Post-Synaptic Potential
| IPSP - Inhibitatory Post-Synaptic Potential
74
Between skeletal and cardiac muscle, which one is triad and which one is dyad?
Skeletal - Triad
| Cardiac - Dyad
75
Why is a cardiac action potential longer than a skeletal?
```
Prevents tetany (involuntary contraction of muscle)
Protects against re-entrant arrhythmias
```
76
What type of receptor is present on Ca release channels?
Ryanodine receptors
77
How is Ca removed from the sarcoplasm?
```
Via SERCA (sarco/endoplasmic Ca ATP-ase)
Via sarcolemmal Na/Ca exchanger
```
78
What is the force-frequency effect (in heart)?
```
Increasing rate of cardiac contraction results in an increased tension development
Gives treppe (staircase) effect on slow chart recorder
```
79
Do smooth muscle cells have striations?
No
80
What type of receptor does noradrenaline bind to and what does it activate?
Alpha 1 receptor
| G-protein - activates phospholipase C - breakdown PIP2 (phosphatidyl inositol 4,5 biphosphate)
81
What receptor does adrenaline bind to?
Beta 1/2
82
What is unitary smooth muscle?
Not all cells have synaptic input
| Excitation spreads through tissue by gap junctions
83
What is multi-unit smooth muscle?
Each smooth muscle cell has a synaptic input
| Allows finer control of muscle
84
What g-protein is alpha-1 adrenergic receptor associated with and what does it stimulate?
Gq
| IP3/Ca + DAG secondary messenger pathways to raise cellular [Ca]
85
What g-protein is alpha-2 adrenergic receptor associated with and what does it stimulate?
Gi
| Inhibits adenylate cyclase to decrease cellular cAMP
86
What g-protein are beta adrenergic receptors associated with?
Gs
87
Where are each of the beta adrenergic receptors mainly located?
beta-1 - cardiac
beta-2 - vascular + airways
beta-3 - adipose, bladder
88
What non-adrenergic, non-cholinergic neurotransmitters can be released that promote vasoconstriction?
(Along with what NT?)
Neuropeptide Y
ATP
NA
89
What non-adrenergic, non-cholinergic neurotransmitters can be released that promote vasodilation?
(Along with what NT?)
Nitric oxide
Vasoactive intestinal polypeptide
AcH
90
Under normal circumstances, what branch of the nervous system is heart rate under the control of?
Peripheral Nervous System
91
What is the NTS in the brain stem?
Nucleus Tractus Solitarus
92
What does the Botulinum toxin A do and what is it used to treat?
(How treat?)
Binds to and degrades SNAP-25, preventing exocytosis of AcH and other N.T
Treat an overactive bladder - prevent stimulation of muscarinic receptor on detrusor muscle
93
Where should a drug be targeted for:
a) widespread effect
b) specific target
a) Sympathetic nerves in CNS/Sympathetic ganglion
| b) Neuroeffector junction
94
What drug can be used to inhibit noradrenaline synthesis?
Alpha methyl tyrosine
95
What drug can inhibit noradrenaline storage and what does it do?
Reserpine
| Block VMAT
96
How is noradrenaline normally uptaken into vesicles?
Via Vesicular Monoamine Transporter (VMAT)
97
What is noradrenaline metabolised by if not reuptaken?
| Other hormones with this enzyme as well
```
Monoamine Oxidase (MAO)
Dopamine, Serotonin
```
98
What drug(s) can inhibit noradrenaline release and how?
Clonidine
| Alpha-2 adrenergic receptor specific agonist and activation of these receptors inhibits N.T. release
99
```
What drug(s) can promote noradrenaline release?
(Secondary effect of one?)
```
Amphetamine - also inhibits MAO, increase free NA
Tyramine
Ephedrine
100
What selective blocker(s) block alpha 1 adrenergic channels?
Doxazosin
| Tamsulosin
101
What is an example(s) of a non-selective beta blocker?
Labetolol
| Propanolol
102
What is an example(s) of a beta-1 selective blocker?
Atenolol
103
What are some adverse effects of beta blockers?
```
Fatigue
Reduced Peripheral Blood Flow
Bronchoconstriction
Increased risk of Cardiac Failure
Risk of hypoglycemia
```
104
What receptor does Salbutomol effect?
Selective agonist of beta-2 receptor
105
What 2 enzymes are endogenous and exogenous catecholamines broken down by?
MAO - Monoamine Oxidase
| COMT - Catechol-O-Methyl Transferase
106
What drugs inhibit MAO?
Phenylzine
Moclobemide
Selegiline
107
What is the top, middle and bottom bit of the stomach called?
Fundus
Corpus
Antrum
108
What chemical messengers are parietal cells acid secretion regulated?
AcH
Histamine
Gastrin
109
What enzymes do the pancreas, SI, and salivary glands secrete to digest carbs?
Pancreas - alpha amylase
Salivary glands - alpha amylase
SI - 1,6-glucosidase
110
What enzymes does the stomach, pancreas and SI secrete to digest proteins?
Stomach - pepsins, HCl
Pancreas - Carboxypeptidases
SI - Amino-peptidases, dipeptidases
111
What hormone causes contraction of gall bladder and where is it secreted from?
(What else does the hormone cause?)
Cholecystokinin
Secreted by cells in duodenum
Relaxation of sphincter of Oddi
112
What is bilirubin?
Yellow compound that occurs in normal catabolic pathway
| From breakdown of heme
113
What are enterocytes?
Intestinal absorptive cells
| Columnar epithelial, line inner surface of SI and LI
114
What are chylomicrons?
Re-esterified LCFA, monoglyc, lysophospholipids, cholesterol (absorbed by enterocytes)
Have specific apoproteins
115
Where are apoproteins made in enterocytes and where do they go?
In RER
| Moves to SER + associates with newly synthesised trigylcerides
116
What is the receptor for AcH in the heart?
Muscarinic AcH receptor (mAcHR)
117
What nerve supplies the parasympathetic innervation for the heart?
Vagus nerve carries parasymp preganglionic axons
118
What is the receptor for noradrenaline in the heart?
Beta-1 adrenoreceptor
119
How is noradrenaline synthesised from tyrosine and what are the enzymes involved?
Tyrosine ==> DOPA (Tyrosine hydroxylase)
DOPA ==> Dopamine (DOPA Carboxylase)
Dopamine ==> Noradrenaline (Dopamine beta-hydroxylase)
120
What is the drug imipramine and what does it do?
Tricyclic antidepressant
| Increases amount of noradrenaline in synapses by inhibiting uptake
121
How is AcH formed and what is the enzyme?
AcCoA + Choline ==> AcH (choline acetyl)
| Choline acetyl transferase
122
Is AcH excitatory or inhibitory at:
a) Heart cells
b) Skeletal muscle
a) Inhibitory
| b) Excitatory
123
What is the receptor in the skeletal muscle for AcH?
Nicotinic AcH Receptor (nAcHR)
124
What is myasthenia gravis?
When body produces antibodies against nAcH receptors
125
What receptor is on blood vessels in the gut for noradrenaline?
Alpha-1 adrenergic
126
What receptor is on blood vessels in skeletal muscle for noradrenaline?
Beta-2 adrenergic
127
What receptor is on sweat glands for AcH?
Muscarinic AcH receptor
128
What is pilocarpine?
Muscarinic AcH receptor agonist
129
What nerve is associated with parasympathetic stimulation of the salivary glands?
Chorda lingual nerve
130
What is the max rate of salivary flow in humans?
1ml/min.g
131
What is intrinsic factor?
Glycoprotein combines with vitamin B12
| Aiding absorption in ileum
132
What is the section of the stomach just before the duodenum?
Pylorus
133
What are the 3 stages of stomach digestion?
Propulsion
Grinding
Retropulsion
134
What cell(s) in the stomach secrete HCl?
Parietal (oxyntic) cells
135
What cell(s) in the stomach secrete mucus?
Superficial epithelial cells
| Mucous neck cells
136
What cell(s) in the stomach secrete pepsin and other digestive enzymes?
Chief cells
| Endocrine cells
137
What are fenestrated capillaries?
Capillaries that have pores that allow larger molecules through
138
What is the constant concentration parietal cells secrete H+?
150mEq/L
139
What is an ECL cell?
Enterochromaffin-like cell
| Neuroendocrine found in gastric glands of gastric mucosa beneath epithelium
140
What endocrine hormone(s) does the D cell secrete and what does it do?
Somatostatin
| Binds to g cell in stomach epithelium, limits further gastrin secretion
141
What does the drug omeprazole do?
Selectively and irreversibly inhibits H+, K+, ATP-ase by forming a disulphide link
Prevent acid secretion
142
What cells help regulate the rhythmic cycles of activity of the visceral smooth muscle?
Pacemaker cells (interstitial cells of Cajal)
143
How many litres of food are ingested before the stomach pressure stops being constant?
1L
144
What is the frequency of peristaltic waves in the stomach when food is being digested?
3 per minute
145
How much chyme is usually delivered to the duodenum?
3ml
146
What are the hormones involved in the regulation of gastric activity?
Secretin
Cholecystokinin (CCK)
Gastric Inhibitory Peptide (GIP)
Motilin
147
What are the 2 interconnected plexuses in the enteric nervous system?
Myenteric
| Submucosal
148
What transporter transports fructose?
GLUT5
149
What are oligopeptides?
Peptide molecule that have small no of AA residues
150
How are oligopeptides absorbed into the intestine?
H+/Oligopeptide cotransporter PepT1
| Into enterocyte across apical membrane
151
What are the 2 membranes in an enterocyte?
Apical membrane
| Basolateral membrane
152
What is Hartnup disease?
Autosomal-recessive disorder
L-phenylalanine cannot be uptaken
Can absorb if in form dipeptide L-phenylalanyl-L-leucine
153
What is cystinuria?
Autosomal recessive disorder
L-arginine cannot be uptaken
Can absorb if in form dipeptide L-arginyl-L-Leucine
154
How is vitamin A absorbed from intestine?
Absorbed and transported in newly synthesised chylomicrons
| Taken up by liver for further hydrolysis of retinyl esters
155
How is vitamin E absorbed?
Absorbed primarily in form of alpha and gamma tocopherol
| Incorporated into chylomicrons + VLDL
156
What enzymes hydrolyse dietary retinyl esters in the lumen?
Pancreatic triglyceride lipase (PTL)
Pancreatic Lipase-related Protein 2 (PLRP2)
Intestinal brush border enzyme - phospholipase B (PLB)
157
What happens to unesterified retinol(ROH)?
Passively diffuses into enterocytes
Complexed with cellular retinol binding protein type 2 (CRBP2)
Re-esterified by retinol acyltransferase
158
What is the active form of vitamin D called?
Calcitriol
159
What are the 2 types of nephrons?
Cortical (85%) - outer 2/3 of cortex, short loops of Henle
| Juxtamedullary (15%) - inner 1/3 of cortex, long loops of Henle
160
What are the names of the capillaries around the loops of Henle?
(Name when not around loops of Henle?)
Vasa recta
| Glomerular + peritubular
161
What is glomerular filtration rate(GFR)?
Volume of fluid filtered from glomeruli p/min in ml/min
162
What 3 factors does GFR rely on?
Starling forces
Surface area of filtration interface
Hydraulic permeability of capillaries
163
What does PAH clearance equal?
Renal plasma flow
164
Where is sodium reabsorbed in the loop of Henle?
Passive in thin ascending limb
Actively in thick ascending limb
Not in descending limb
165
What are the 2 types of cells in the collecting ducts?
Principal cells
| Intercalated cells
166
What is urea?
Breakdown product of protein
167
What is tonicity?
Concentration of only non-penetrating solutes
168
What type of aquaporins are on the:
a) Luminal membrane
b) Basolateral membrane
a) AQP2
| b) AQP3 + AQP4
169
What does a low water intake do to plasma osmolality?
Increase it
170
What is diuresis?
Increases/excessive production of urine
171
What factors other than osmoreceptors can control ADH and what are their effects?
Inhibit - alcohol
| Stimulate - nicotine, nausea, pain, stress
172
What are the 2 main types of diabetes insipidus?
Neurogenic - congenital/head injury
| Nephrogenic - inherited (mutated V2 receptor)/aquired
173
What 3 elements maintain K balance?
Renal excretion
Gastrointestinal losses
Cellular shifts
174
What is hypokalemia?
Plasma [K+] < 3.5mM
175
What is hypokalemia caused by?
Increased external losses
Redistribution into cells
Inadequate K+ intake
Increased external losses in urine
176
What is hyperkalemia?
Plasma [K+} > 5.5mM
177
What is hyperkalemia caused by?
Decreased external losses
| Redistribution out of cells
178
What are the 5 actions of angiotensin II?
```
Stimulates proximal tubule Na+ reabsorption
Stimulates ADH release
Causes aldosterone secretion
Causes thirst
Vasoconstricts small arterioles
```
179
What is the AT1 receptor, where is it located and what does it cause?
Angiotensin II Type 1 receptor
Present on luminal + basolateral membrane
Stimulates Na+ reabsorption
180
What peptides are released when the heart stretches due to high blood volume/pressure?
Natriuretic peptides (NP)
181
What are the 2 types of NP?
ANP - secreted from atrial myocardium
| BNP - secreted from ventricular myocardium
182
Where does bicarbonate (HCO3-) reabsorption occur?
Proximal tubule
Ascending LoH
Cortical collecting duct - intercalated cells type A
183
What is the cause of respiratory acidosis?
Caused of insufficient CO2 excretion by lungs
184
What are the 2 types of respiratory acidosis?
Acute - abrupt failure in ventilation
| Chronic - 2ndary to many diseases e.g. airway obstruction, lung damage
185
What are the 3 main responses in the body to regulate acid-base status?
Chemical buffers
Brainstem respiratory centre
Renal mechanisms
186
What is metabolic acidosis characterised by?
A fall in plasma bicarbonate conc
187
What is the cause of respiratory alkalosis?
Excessive central respiratory drive
188
Does colon epithelium have villi?
No, it's flat with deep crypts
189
What are the 2 types of water absorption?
Paracellular - via tight junctions between cells
| Transcellular - across cell membranes via aquaporins
190
What is action of the cholera toxin?
Permanently activates adenylyl cyclase
Elevating cAMP in crypt cells
Enhancing secretion
191
What is the most prevalent bacteria in gut flora?
Gram negative bacteria
| Bifido bacteria
192
What type of bacteria can breakdown fibre?
Colonic bacteria
193
Calculation for mean arterial blood pressure (MABP)?
MABP = CO x TPR
| cardiac output x total peripheral resistance
194
What 2 things does increasing the length of the sarcomere cause?
Increased cross-bridge overlap
| Increased Ca sensitivity of myofilaments (troponin C)
195
Briefly describe vascular smooth muscle contraction with noradrenaline
Noradrenaline binds to alpha 1 receptor
Activates g protein, activates phospholipase C which breaks down PIP2 ==> IP3 + DAG
IP3 - open channel on SR, release Ca2+
DAG - Open RGC, increase Ca2+ + membrane depolarisation by opening VGCC
Goes to neighbouring cells via gap junctions
G protein also activates rho kinase which increases Ca2+ sensitization
196
Briefly describe NO-mediated vasodilation
NO activates guanylate cyclase, converts GTP ==> cGMP which activates protein kinase G
Opens K+ channels on membrane + membrane hyperpolarized (also VGCC closed so x Ca2+ enter)
SERCA + PMCA ATPases activated so Ca2+ decrease
cGMP broken down ==> GMP by phosphodiesterase (PDE)
197
Briefly describe cAMP mediated vasodilation
Binding of adrenaline/adenosine/prostacyclin to beta 1/2 receptors
Activates adenylate cyclase which ATP ==> cAMP
Activates protein kinase A, same effects as protein kinase G
cAMP broken down ==> AMP by PDE
198
What are spontaneous oscillations in smooth muscle called?
Slow wave (most visceral sm)
199
What are autacoids?
Physiologically active factor released by cells typically acts locally + briefly on other cells
200
How many subunits in a nicotinic receptor and what receptors are found in muscle + ganglionic?
```
5 subunits
Muscle receptor (N1) - 2 x alpha 1 type, beta 1, gamma, epsilon
Ganglionic receptor (N2) - 2 x alpha 3 type, 3 x beta 4 type
```
201
What is the difference between antagonist and agonist?
Antagonist blocks receptor + blocks response
| Agonist binds to receptor + stimulates response
202
What causes gallstones?
Too much H2O absorption from bile
Too much bile acid absorption from bile
Too much cholesterol in bile
Inflammation of epithelium
203
Outline cobalamin handling by stomach + proximal SI
Cobalamin bound to proteins in food - acid pH + pepsin release it from dietary protein
Gastric glands secrete haptocorrin, bind to CBL
Gastric parietal cells secrete IF
Pancreas secretes HCO3- + proteases
CBL released after proteolytic degradation of haptocorrin
IF-CBL complex forms which ileal enterocyte absorbs
204
How do glomerular mesangial cells alter their S.A for filtration?
Contain sm filaments that can contract cell
205
What Na transporters are present on the luminal membrane of the proximal tubule?
Na+-H+ exchanger (NHE3) (Na+ into cell)
| Na+-Glc/AA symporter
206
What Na transporters are present on the luminal membrane of the thick ascending limb?
Na+-K+-2Cl- cotransporter
(N+, K+ into cell)
K+ channel (K+ into filtrate)
207
What Na transporters are present on the basolateral membrane of the thick ascending limb?
Na+-K+ ATPase pump
208
What Na transporters are present on the basolateral membrane of the distal tubule?
Na+-K+ ATPase pump
209
What Na transporters are present on the luminal membrane of the distal tubule?
Na+-Cl- cotransporter
210
What Na transporters are present on the luminal membrane of the principal cells of collecting duct?
Na+ channel
211
What Na transporters are present on the basolateral membrane of the principal cells of collecting duct?
Na+-K+ ATPase pump
212
What do these values of Ch2o reflect?
a) >0
b) = 0
c) <0
a) Hypo-osmotic (dilute) urine
b) Iso-osmotic urine
c) Hyper-osmotic (concentrated) urine
