CEP Flashcards

(259 cards)

1
Q

Endocrine signalling

A

Secreting hormone into blood to reach target cell

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2
Q

Paracrine signalling

A

Hormones secreted to reach nearby cells

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3
Q

Autocrine signalling

A

Hormones to a local effect (target sites on the same cell)

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4
Q

How is the response to a drug/hormone measured?

A

Radio ligand binding assay
Amount of radioactivity is proportional to number of receptors

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5
Q

EC50

A

Effective concentration 50%
The concentration required to make 50% response (effect)

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6
Q

Kd (dissociation constant)

A

50% of receptors occupied (binding)

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7
Q

Affinity equation

A

1/Kd (low Kd = high affinity)

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8
Q

Why measure ligand binding?

A

To see affinity of drug

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9
Q

Endocrinology

A

The study of hormones

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10
Q

What are the four types of hormone?

A

Protein (insulin)
Steroid (cholesterol)
Amine/small peptide (tyrosine)
Amino acid derivatives

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11
Q

How are hormones measured?

A

Bioassays
Immunoassays
Mass spectrometry

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12
Q

What are the anterior pituitary hormones?

A

ACTH
TSH
GH
LH/FSH
PRL

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13
Q

What are the posterior pituitary hormones?

A

Vasopressin
Oxytocin

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14
Q

How to treat underactive glands?

A

Hormone replacement
Can be due to autoimmune
Primary/secondary can effect later on down the line and not appear until then

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15
Q

How to treat over active glands?

A

Block receptors
Often caused by tumours (surgery)

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16
Q

What are the 4 main types of receptors?

A

Ligand-gated ion channels (ionotropic)
G-proteins coupled receptors
Kinase-linked receptors
Nuclear receptors (not on plasma membrane)

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17
Q

What is the mechanism of ionotropic/ligand-gated ion channels?

A

Ion channels open when ligand binds
Causes change in membrane potential as +/- ve charges change
Can cause depolarisation/hyperpolarisation

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18
Q

What is the mechanism of GPCRs?

A

Ligand binds
G protein activates/changes conformation
Has a postage or negative effect
Causes ions channels to open or enzymes to produce second messenger
Resulting in a signalling cascade

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19
Q

What is the mechanism of kinase-linked receptors?

A

Ligand bonds directly to enzyme
Conformation change
Phosphorylation cascade occurs
Gene transcription
Protein synthesis

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20
Q

What is the mechanism of nuclear receptors?

A

Ligand diffuses directly across the membrane
Binds in nucleus to transcriptional factor
Gene transcription
Protein synthesis

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21
Q

What is the fastest receptor?

A

Fastest: l-g ion channels
GPCRs
Kinase-linked receptors
Nuclear receptors

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22
Q

How does Adenylyl cyclase work?

A

AC is an effector enzyme activated by a g-protein
It converts ATP into cyclic AMP which is a second messenger

Signal is stopped by cAMP phosphodiesterase

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23
Q

How does phospholipase C work?

A

It has 2 second messengers
Gq activates PLC
Causes PIP2 to convert to DAG and InsP3
Causes Ca2+ to be released from ER

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24
Q

What does a protein kinase do?

A

Adds phosphate

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25
What does a proteins phosphatase do?
Removes phosphate
26
What can mutations in receptor genes lead to?
Inactive (no function or under) Or over active (tumour/hyper function)
27
What is the thyroid pathway?
Hypothalamus released TRH Anterior pituitary TSH Thyroid released T3, T4 Increases metabolism
28
TSH resistance
Hypothyroidism Not enough thyroid activity Treated by more TSH
29
Cushing’s syndrome
Adrenal tumor Benign adenoma
30
What is the endocrine system?
A system of ductless glands and cells that secrete hormones Regulates metabolism, homeostasis, reproduction
31
Exocrine glands
Realise their secretions outside of the body May be ducted Not part of endocrine system
32
Intercrine signalling
Acting within the same cell
33
Hormones are controlled by…
Feedback (usually negative)
34
How does negative feedback work?
Senses the change and activated the mechanism to reduce it The final product of an endocrine cascade acts to inhibit the release of hormones
35
Axis
How glands communicate
36
Peptide/protein hormones
Mainly from pituitary Made from chains of amino acids Hydrophilic No carrier needed in blood Stored in membrane bound vesicles (to be released via exocytosis) Produce on RER as pre-prohormone which is broken by proteolysis
37
Steroid hormones
Made from cholesterol Converted to pregnenolone via CYP11A This then can differentiate using other enzymes Hydrophobic (won’t travel in blood) Can’t store in vesicles so synthesised as required
38
Where is aldosterone made?
Adrenal cortex Zona glomerulosa
39
Where is cortisol made?
Adrenal cortex Zona fasciculata
40
Where is adrenal androgens made?
Adrenal cortex Zona reticularis
41
How are steroid hormone signals stopped?
Inactivated metabolism transformations Excretion in urine/bile
42
Amine hormones
From thyroid gland T4 Contains 4 iodine atoms T3 contains 3 iodine atoms Small, non polar -> hydrophobic Soluble in plasma membrane Require carrier proteins
43
What do carrier proteins do?
Increase solubility Increase half life Reservoir in blood Can have specific and non-specific (looser binding) kinds
44
Where to hormones bind?
Protein- cell surface receptors Steroid- intracellular receptors
45
What’s HRE?
Hormone response element Specific areas for hormones to bind in DNA
46
Exogenous
Come from sources outside of living things
47
Endogenous
Come from sources within a living thing
48
Potency
the strength of an intoxicant or drug, as measured by the amount needed to produce a certain response.
49
Pharmacology
The study of mechanism or drug action
50
Drug
Active ingredient in a medicine
51
What drugs produce an effect by not binding to a receptor? (Physicochemical properties)
Antacids Laxatives Heavy metal antidotes (EDTA) Osmotic diuretics General anaesthetics Alcohol
52
Most drugs have ___ potency
High So effect at very low concentrations
53
Biological specifity
Receptor wise Natural, biological, endogenous receptor/target
54
Chemical specifity
Drug wise Artificial, chemical, exogenous ligand/drug/agonist
55
Stereo selectivity
In vivo razemisation (equilibrate back to both isomers) So always both forms appear
56
What can drugs be classified by?
Chemical nature Symptoms/disease Organ system effected Receptor Duration of action Generations Route of administration
57
Affinity
The binding strength of the drug receptor interaction Or Likelihood of binding
58
Receptor in pharmacology
Anything that causes a physiological effect when interacting with a drug
59
Law of Mass action
Le chantelier’s principle A + R <-> AR
60
E max
Maximum response
61
Relationship between drug conc and response
Continuous Saturation Exhibits threshold
62
Kd equation
Kd = [A][R] / [AR] Mol/litre
63
Langmuir isotherm
P= [A] / (Kd + [A])
64
Kd vs EC 50
EC 50 is model free equivalent to Kd (has to be the classic curve)
65
Agonist
Bind to receptor to produce response Can be endogenous (given from outside also) and exogenous
66
Antagonist
Binds to receptor but no response Prevent agonist binding so inhibits Has affinity but no efficacy
67
Antagonist vs inhibitor
Inhibitor - enzymes Antagonist -receptors
68
Types of antagonists
Competitive- unbind and rebind Irreversible- covalent binding, same site Allosteric- alternative site Channel blockers- plug channel Physiological- no binding
69
ADME
Absorption, distribution (drug to target) Metabolism, Excretion (remove drug)
70
Effective concentration
The lowest concentration needed to make an effect
71
Therapeutic window
The concentration window between the toxic and effective concentration
72
Where can the drug be lost when administered?
Not dissolved Broken down by stomach acid/intestine Not absorbed Secreted into bike Metabolised Bound to plasma proteins Excreted Tissue bound
73
Routes of administration
Enteral (oral, rectal) Parenteral (subcutaneous, intra-muscular, intra-venous) Percutaneous (inhalation, sublingual, topical, transdermal)
74
Absorption depends on…
Route Blood flow at site Dose Active vs passive diffusion Solubility Chemical nature Molecular weight Partition coefficient Gastric mobility pH at site Area of absorbing site Presystemic elimination Ingestion with/without food
75
Bioavailability
The fraction of the total dose administered that reaches the plasma
76
Factors that affect absorption in GI tract
Dispersal/solubility of drug in gut Stability in acid/alkali Lipid solubility Time available for absorption Concentration of drug Blood flow Interaction with food Effect of drug (irritant) Effect of meals First pass metabolism
77
Pharmaceutical interventions that effect absorption
Particle size Dry-powder inhaler Enteric coated tablets Slow release
78
Factors effecting transdermal absorption
Lipid solubility Formulation Skin thickness Hydration Blood flow
79
Pinocytosis
Endocytosis of fluid and dissolved molecules (opposite of exocytosis)
80
Lipophilicity
Likes lipids
81
Distribution of drugs depend on
Lipid solubility Diffusion barriers Tissue binding Plasma protein binding
82
Albumin
Family of soluble globular proteins that transport small molecules in the blood Decreased levels in liver and kidney disease
83
Alpha-acid glycoprotein
A carrier of basic and neutral lipophilic compounds Increased in inflammatory conditions
84
Process of pharmokinetics when drug testing
Lipophilic/hydrophilic pH value Active perfusion Large surface area Diffusion barriers Any inactivating enzymes
85
Diffusion barriers
Block diffusion across membranes Main types- BBB, placenta
86
Apparent volume distribution
The notional volume of fluid required to dilute the absorbed dose to the concentration found in plasma
87
AVD equation
AVD = dose / plasma concentration
88
High AVD
Tissue bound Lipophilic and basic
89
Low AVD
Heavily plasma protein bound
90
Ion trapping
Passive, semipermeable membrane Only the unionised molecule will travel across the membrane So a high concentration of an acidic drug will be concentrated in a compartment with high pH
91
Metabolism
Mainly liver (first pass), kidney, skin, lungs, microbiome Basically anything in can do chemically with a drug Mainly **oxidation and conjunction** Unusually inactivated but not always
92
Oxidation via
Cytochrome p450 enzymes
93
Conjunction via…
Sulfation pathways
94
Portal vein
Something that vascularises twice
95
First pass metabolism
Phase 1- oxidation via cytochrome p450 enzymes -hydroxyl groups -> more hydrophilic Phase 11- conjunction reactions - charged groups are conjugated -> more hydrophilic
96
Excretion
Kidney -into urine Liver -into bile (enterohepatic circulation) Lungs Fluids -salvia, sweat, milk
97
Performing a PK study
Dose Collect samples (blood, urine etc) Analysed drug PK data analysis
98
How to quantitatively measure drugs in excretion?
Mass spec Liquid chromatography LC-MS
99
Dose interval dependent on…
Plasma half life
100
Hormones in anterior lobe
ACTH (Adrenocorticotropic hormone) TSH (thyroid stimulating hormone) GH (growth hormone) FSH/LH (follicle-stimulating hormone/ luteinising hormone) PRL (prolactin)
101
Hormones in posterior lobe
Vasopressin (ADH) Oxytocin
102
What is the hypothalamus regulated by?
Hormone mediated signals Neural inputs
103
Uses of hypothalamus…
Final common pathway to anterior pituitary Non-endocrine function (thirst etc) Sends signals to other parts of nervous system
104
Posterior pituitary communication
Only through nerves Secretory granules migrate down axons (supraopyicohypopophyseal) No hormones produced here only secreted
105
What does the hypothalamus secrete?
corticotrophin-releasing hormone dopamine growth hormone-releasing hormone somatostatin gonadotrophin-releasing hormone thyrotrophin-releasing hormone
106
What does GHRH stimulate?
Growth hormone
107
What does somatostatin do?
Inhibit growth hormone
108
What does GnRH stimulate?
Follicle-stimulating hormone Luteinizing hormone
109
What does CRH stimulate?
ACTH
110
What does TRH stimulate?
TSH
111
What does dopamine stimulate?
Inhibits prolactin
112
Growth hormone release
Stimulated by hypoglycaemia, exercise and sleep Suppressed by hyperglycaemia Released in pulses throughout the day
113
What is GH mediated by?
Effects mediated by IGF-1
114
What does GH stimulate?
Protein synthesis Lipolysis Glucose metabolism Acquisition of bone mass Regulation of body composition Well-being
115
What does FSH and LH trigger?
LH- testosterone production in tested FSH- oestrogen production in ovaries
116
What is the secondary effect of FSH?
Estrogen -> breasts, hips broaden, pubic hair, folliculogenesis
117
What is the secondary effect of LH?
Testosterone -> penis/scrotum grow facial hair grows larynx elongates shoulders broaden hair grows muscle increases in body spermatogenesis
118
What does prolactin do?
Lactation But also inhibits GnRH (less FSH/LH)
119
What does ACTH do?
Stimulates cortisol production in adrenal gland -> regulates blood sugar, increases fat, help defends body against infection, respond to stress
120
What does TSH do?
Stimulates the thyroid -> that produces T3 and T4
121
Where is vasopressin synthesised?
Supraoptic and paraventricular nuclei of hypothalamus
122
What does vasopressin do?
Determines the rate of free water excretion By changing the permeability of the luminal membrane of cortisol and medullary collecting tubes
123
What stimulates ADH?
Hyperosmolality (too much water) Effective circulating volume depletion (blood loss)
124
What does oxytocin do?
Stimulates contraction of smooth muscle in Breast and uterus -> milk ejection reflex -> parturition (birth)
125
Pituitary disease manifestations
Neurological Visual Hypopituitarism Hormone hypersecretion from adenoma
126
Lesion
Damage to tissue
127
Mass neurological effects of pituitary lesions
Headaches Brain damage/hypothalamic damage Nerve damage Optic nerve damage CFS leak
128
Hypopituitarism causes
Tumours Radiotherapy Pituitary infarction (Sheehan’s syndrome) Infiltration of pituitary Trauma Isolated hypothalamic hormone deficiency (Kallmann’s)
129
What is apoplexy?
Bleeding into an organ / loss of blood flow to an organ
130
Infiltration of pituitary
Lymphatic infiltration causes inflammation
131
GH deficiency manifestation
Children- poor growth Adults- more abdominal fat, less muscle strength, impaired cardiac function, decreased bone mineral density
132
How to diagnose GH deficiency?
ITT glucagon GHRH+arginine IGF-1 (blood test)
133
GH deficiency treatment
Hormone replacement
134
FSH/LH deficiency manifestations
Delayed puberty Osteoporosis Anaemia Men- libido decreased, infertility, less muscle mass, less mood Women- libido decreased, infertility m, dyspareunia
135
FSH/LH deficiency diagnosis
Blood test of hormones Oestradiol Menstrual history Morning testosterone
136
FSH/LH treatment
Hormone replacement
137
ACTH deficiency manifestations
Fatigue Weakness Nausea/vomiting Anorexia Hypoglycaemia Hypotension Anaemia
138
ACTH diagnosis deficiency
9am serum cortisol and ACTH Dynamic: short synacthen test, ITT, glucagon test
139
Alpha sub units on G proteins
Ga s Ga io Ga q11
140
ACTH deficiency treatment
Replace what is missing (steroids) Approximate to the natural rhythm
141
TSH Deficiency manifestations
Fatigue, weakness Cold intolerance Bradycardia Inability to lose weight Puffiness Pale/dry skin Constipation
142
TSH deficiency diagnosis
TSH, fT3, fT4 tests
143
Treatment for TSH deficiency
Hormone replacement (levothyroxine)
144
Diabetes insipidus
Deficient secretion of ADH
145
Diabetes insipidus causes
Idiopathic (autoimmune) Familial (autosomal dominant mutations, Wolfram syndrome) Tumours Neurosurgery Infiltration disorders Infections Hypoxic encephalopathy
146
Hypoxic encephalopathy
When blood doesn’t receive enough oxygen for a period of time
147
ADH deficiency manifestations
Polyuria (lots of urine)
148
Causes of polyuria
Osmotic diuresis (DM, renal failure) Primary polydipsia Diabetes insipidus
149
ADH deficiency diagnosis
Urine output Blood (electrolytes, glucose, urea, creatinine) Water deprivation test
150
ADH deficiency treatment
ADH analogues (replacements)
151
Functioning vs non-functioning pituitary adenomas
Functioning- secrete hormones from tumours Non- no secretion
152
GH hypersecretion causes…
Acromegaly
153
Acromegaly symptoms
Gigantism Arthritis Hypertrophy of frontal bones Hyperhidrosis Etc
154
Acromegaly diagnosis
Oral glucose tolerance test IGF-1 Pituitary Imaging
155
Acromegaly treatment
Pituitary surgery Dopamine agonists Somatostatin analogues GH receptor antagonists Radiotherapy
156
High prolactin causes
Stress, pregnancy, lactation, sex, sleep Antipsychotics, antidepressants, opiates Hypothalamic tumours
157
Prolactinoma manifestation
Hypogonadism (lack of sex hormones) Galactorrhoea Mass effects
158
Prolactionoma diagnosis
Pituitary imaging
159
Prolactinoma treatment
Dopamine agonists Surgery Radiotherapy
160
Cushing’s syndrome
Too much cortisol Could be due to too much ACTH or adrenal disease/steroids
161
Cushing’s disease
Excess ACTH from corticotroph adenoma
162
Cushing’s syndrome symptoms
Weight gain Slow healing of cuts Fatigue High risk of infections Glucose intolerance Moon face/ buffalo hump Red marks (striae)
163
Cushing’s diagnosis
24hr UFC (cortisol in urine) Midnight serum cortisol Overnight/low dose dexamethazone suppression test 9am ACTH Imagining
164
Cushings treatment
Pituitary surgery Radiotherapy Drugs Bilateral adrenalectomy
165
TSHoma (mani, diag and treat)
Mani- Thyrotoxicosis Diag- Hormonal tests Imaging Treat- Surgery/meds/radiotherapy
166
FSHoma
Mani- Menstrual irregularities Ovarian hyper stimulation Testicular enlargement Infertility Diag- hormonal tests Imaging Treat- Surgery Radiotherapy
167
What protein hormones made up of?
An alpha and beta subunit
168
What do TSH, LH, FSH and hCG all share?
The same type of alpha subunit
169
Thyroid gland embryology
Proliferation on pharyngeal floor (foramen caecum) Descends through thyroglossal duct then duct obliterates (or becomes thyroglossal cyst)
170
Thyroid gland location
Anteriorly: strap muscles Sternohyoid, sternothyroid Laterally: sternocleidomastoid muscle Can only palpate isthmus
171
Thyroid blood supply
Superior thyroid artery (first brand of external carotid artery) Inferior thyroid artery (from thyrocervical trunk) Superior (into jugular vein) Middle (into jugular vein) Inferior thyroid veins (into brachiocephalic vein) All together- venous plexus
172
The aortic arch extends to…
Left subclavian artery Left common carotid artery Brachiocephalic artery-> right subclavian and right common carotid
173
Parathyroid glands secrete… and their functions
PTH - regulator of serum calcium Targets kidneys intestine and bone
174
Describe parathyroid glands
Small, flattened oval shaped glands Normally 4 glands On POSTERIOR of thyroid gland
175
Parathyroid gland embryology
Superior parathyroid derived from 4th pharyngeal pouch Inferior derived from 3rd pharyngeal pouch Glands descend with thymus but stop earlier
176
Parathyroid glands blood supply
inferior thyroid artery Superior/middle/inferior veins
177
Adrenal glands location
Superomedial aspect of kidneys Retroperitoneal Level t11-12 Surrounded by Perirenal fat Separated from kidneys by fascia
178
Retroperitoneal
anatomical space located behind the abdominal or peritoneal cavity
179
Adrenal glands structure and secretions
Distinct inner medulla (noradrenaline and adrenaline) and outer cortex (cortisol)
180
Adrenal glands blood supply
Superior adrenal artery (branch of inferior phrenic) Middle adrenal artery (branch of abdominal aorta) Inferior adrenal artery (branch of renal artery) Right adrenal vein (into inferior vena cava) Left adrenal vein (into left renal vein then IVC)
181
Adrenal gland innervation
Directly by preganglionic sympathetic fibres (from mostly greater splanchnic nerve) Adrenal medulla acts as a specialised sympathetic ganglion
182
Endocrine pancreas function
Islets of langerhans Release insulin and glucagon
183
Exocrine function of pancreas
Acinar cells Digestive enzymes
184
Endocrine pancreas embryology
Begins as two buds that develop rotate and fuse (=2 ducts)
185
Endocrine pancreas location
Head -attached to duodenum to the right anterior to IVC, right renal artery and vein and left renal vein Bile duct is embedded in its posterior surface Neck- overlies superior mesenteric vessels Formation of portal vein occurs posteriorly Body- left of superior mesenteric vessels Posterior surface in contact with aorta, SMA left Kidney and adrenal Tail- enters lienorenal ligament Related to splenic hiking and left colic flexure
186
mesentery
Fold in membrane that attaches the intestine to the abdominal wall
187
Dirty drugs
Bind to more than one receptor Side effects
188
The nature of drug receptors
Enzymes Ion channels Transports Physiological receptors DNA/RNA Substrates, metabolites and proteins Monoclonal antibodies
189
Efficacy relative to endogenous agonist scale=
Full inverse agonist Partial inverse agonist Silent antagonist Partial agonist Full agonist Super agonist
190
Ways to regulate cell function
Alter membrane potential Alter enzyme activity Alter gene expression
191
GABA a receptor
Ligand gated choride ion channel Benzodiazepine binds to allosteric site and increased affinity of binding
192
Glutamate gated chloride receptors
Common channels in nervous system Important targets for anti parasitic drugs
193
Spare receptors/super agonists
Some ‘super agonists’ can produce maximal response without binding to all available receptors Emax > 100%
194
Partial agonists
Low efficacy, cannot produce maximal response even when bound to all receptors
195
Competitive antagonist
Bind reversible Parallel shift of dose/response curve
196
Irreversible antagonist
Being covalently Decrease the maximal response Can still produce max response -> evidence for spare receptors
197
Allosteric antagonism
Being reversibly at different site to agonist Decrease agonist affinity Reduced likelihood of agonist binding
198
Channel blockers
Bind inside and prevent passage of ions Tend to be enhanced by receptor activation
199
Physiological antagonist
Not binding to receptor
200
Desensitisation
Prolonged exposure can reduce response to drug
201
Allosteric effects on receptors
Change shape for good or bad
202
Two types of acetyl choline receptors
Nicotinic Muscarinic (GPCR)
203
How to get drugs/signals across a membrane?
Integral ion channels Integral tyrosine kinases Steroid receptors/nuclear receptors GPCRs Cytokine receptors
204
Nuclear receptors location
Act In nucleus But mostly located in the cytoplasm When steroid bound then conformational change
205
DBD
DNA binding domain mediates binding of nuclear receptors
206
Types of G subunit
Gs stimulating cAMP pathway Gi inhibiting Gq stimulating PLC pathway
207
Diabetes diagnosis
Random >11.1mmol/l Fasting glucose >7mmol/l HbA1c >48mmol/mol Need to repeat test if no symptoms
208
HbA1c
Reflects previous 10 weeks of ambient circulating glucose 65% or 48mmol/mol Can be to diagnose Or measure how well diabetes is being treated
209
Oral glucose tolerance test
Gold standard Fasting state Measure glucose (>7) Drink 75g of glucose Wait 2 hours then measure glucose (>11.1)
210
Cause of diabetes
Insulin deficiency or resistance
211
Insulin anabolic function
Maintain supply of glucose to tissues Regulates metabolism in muscles Promotes protein synthesis Inhibits breakdown of fat
212
Symptoms of diabetes
None Weight loss Tiredness Infection Candidiasis Urine Osmotic symptoms Polyuria Thirst Blurred vision Coma
213
Proinsulin
Cleaved by proteases Can be measured as is always produced with each insulin molecule Urinated out
214
Types of diabetes
Type 1 immune system attacks and destroys the cells that produce insulin Type 2 cells don’t respond to insulin Gestational Monogenic
215
Cause of type 1
T cells attack insulin beta cells in islets of langerhan
216
Treatment of type 1
Lifestyle- lower glucose levels when they are exercising Insulin
217
Insulin delivery system (midlands hybrid closed loop pilot outcomes)
Glucose level sensing Sends signals to machine Diffuses insulin into body
218
Treatment of type 2
Lifestyle Give drugs that Reduce insulin resistance (metformin, sitagliptin, liraglutide) Give insulin (gliclazide, insulin injections) Give something that will Increase glucose excretion (SGLT2 inhibitors: dapagliflozin)
219
Diabetes treatment not for glucose
Blood pressure- ACE, beta blockers, ca channel blockers, diuretics Lipids- statins, fibrates
220
Uncontrolled diabetes
Hypoglycaemia- shaky, sweaty, dizzy, hungry, nervous, upset, tired, weak Hyperglycaemia- dry mouth, thirst, weakness, headache, blurred vision, urination Long term- Mental health Vascular Cancer
221
Lack of insulin on fat
Triglycerides to glycerol/fatty acids Fatty acids to acetoacetate To urine ketones/blood ketones/ hydroxybutyrate Or to acetone (smell in breath)
222
Why lower blood glucose?
Irritates endothelial cells Causes furring Blocking
223
Complications of diabetes
Micro vascular: Eye Kidneys Neuropathy Macro vascular: Brain Heart Extremities
224
Why does t2 causes more cancer?
High levels of insulin Causes increased growth as stimulates to all cells
225
Care of diabetic patient
Lifestyle advice Glucose control BP cholesterol after 40, 4mmol/l Regular screening Empathy and engagement
226
Apparent volume of distribution
The notional volume of fluid required to dilute the absorbed dose into the concentration found in the plasma
227
Bio transformation of drugs
Phase 1 Oxidation/ hydroxylation/ dealkylation/ deamination/ hydrolysis Phase 2 Conjugation
228
Endocrine cells 3 distinct anatomical distributions are:
Grouped into an endocrine gland Forming discrete clusters Dispersed singly among other cells known as **diffuse neuroendocrine system**
229
What are endocrine cells? (Types)
Epithelial cells mainly But some are neuroendocrine cells
230
Neuroendocrine cells
Secrete amines that are decarboxylated Form a secure link with the ANS Neural crest cell derivative
231
APUD cells
Amine precursor uptake and decarboxylation = neuroendocrine
232
Chromogranin
Core protein expressed by neuroendocrine (associated with hormone)
233
Synaptophysin
Membrane glycoprotein found in neuroendocrine vesicles
234
How to see if neuroendocrine cells are present?
Stain chromogranin or synaptophysin Or directly stain their specific hormone
235
Where are Neuroendocrine cells normally found?
Respiratory GI Tract However not readily seen as scattered
236
Larger endocrine glands composed of neuroendocrine cells…
Adrenal medulla Pancreatic uslets
237
Thyroid gland anatomy
Thin fibrous capsule of connective tissue Made up of follicles
238
Follicles are made of..
Thyroid epithelial C-cells Colloid
239
Use of thyroid hormones
Control of metabolism Regulation of growth Multiple roles in development
240
What is the active thyroid hormone?
T3
241
What’s the difference between t3 and t4?
T4 has 4 iodines T3 has 3
242
What cells produces thyroid hormones?
Follicular thyroid cells
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What are thyroid hormones synthesised from?
Thyroglobulin precursor Tyrosine
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Thyroperoxidase function
Binds iodine to tyrosine residues in thyroglobulin molecules Forms MIT + DIT
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T3 is made of…
MIT DIT
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T4 is made of…
DIT x2
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Thyroid hormone synthesis mechanism
1. TSH binds to TSHR 2. I- uptake by Na/I symporter 3. Iodisation of Tg tyrosyl residues by thyroperoxidase 4. Coupling of iodotyrosyl residues by thyroperoxidase 5. Export of mature Tg to colloid where it is stored
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Which thyroid hormone is more abundant?
T4
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How is t3 converted from t4?
By deiodinase enzymes
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Tests of thyroid function
Serum TSH (best) Serum free T4 Serum free T3
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Hormone levels of hyperthyroidism
Low serum TSH High serum free T4 and free T3
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Hormone levels of hypothyroidism
High serum TSH Low free t4 Low free t3
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Main causes of hyperthyroidism
Graves hyperthyroidism Toxic nodular goitre Thyroiditis Others: Exogenous iodine Factitious TSH secreting pituitary adenoma Neonatal hyperthyroidism
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Distribution of drugs into the CNS depends on?
Lipid diffusion
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What are the different method of elimination?
256
Toxicology is the study of…
Unwanted or deleterious effects of drugs or chemicals in the body
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Diabetes is a metabolic disease that is characterised by…
High blood glucose concentration
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People with diabetes are at a greater risk of what conditions?
Neuropathy Nephropathy Cardiovascular disease Stroke Retinopathy Hearing impairments
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Polyphagia is…
Increased hunger