Patient: Alpha Adrenoceptors COPY

Question 1

Two branches of the autonomic nervous system and what kind of receptors lie there

Answer 1

Sympathetic- noradrenaline

Parasympathetic - acetylcholine

Question 2

Adrenal Medulla

Answer 2

Adrenaline (epinephrine)

which is under he sympathetic nervous system

Question 3

Adenoreceptors modulate the “fight or flight” response. Name 9 examples of tissues where they can act

Answer 3

• Blood vessels
• heart
• Lungs
• GI tract
• Salivary glands
• bladder
• genitalia
• eyes
• sweat glands

Question 4

Name 3 adrenoreceptors

Answer 4

Alpha1, alpha2

beta1, beta2, beta3

Question 5

Functional responses of alpha1 adrenoceptors

Answer 5

• GPCR - Galphaq
• Increases Ca2+ concentration via..activating phospholipase C–>IP3
• vasoconstriction (increase BP)
• Contraction of visceral smooth muscle e.g. bladder sphincter, uterus, iris radial muscle, seminal tract, pilomotor muscles
• Relax GI tract

Question 6

Define seminal tract

Answer 6

Secrete semen

Question 7

Define pilomotor muscles

Answer 7

Contraction of the smooth muscle of the skin caused by mild application of a tactile stimulus or by local cooling and resulting in goose bumps

Question 8

Functional response of alpha2 adrenoceptors

Answer 8

• Decrease in noradrenaline and acetylcholine transmitter release
• Decrease in insulin release
• GPCR Galphai activates adenylyl cyclase
• causes reduction in cAMP
• Decrease in Protein kinase A

Question 9

Functional response of beta1 adrenoceptors in the
Heart
Kidney
Adipocytes

Answer 9

Binds GPCR Galphas
activates adenylyl cyclase
increase in cAMP
increase in protein kinase A hence:
Heart - Increase heart rate (SA node) and increase force of contraction 
Kidney - release of renin 
Adipocytes - activates lipolysis

Question 10

Describe what renin is

Answer 10

Hormone that affects:

• Na reabsorption
• angiotensin 2
• vasoconstrictor

Question 11

Functional response of beta2 adrenoceptors

Answer 11

GPCR 
Galpha2s
activates adenylyl cyclase 
increase in cAMP
increase PKA 

Bronchodilation-vasodilation (sk muscle) very little change in BP

• relax visceral smooth muscle
• bladder
• detrusor muscle
• uterus
• ciliary muscle
• seminal tact
• muscle tremor
• glcogenolysis

Question 12

Define detrusor muscle

Answer 12

Muscle that forms layer of wall in the bladder

Question 13

Define ciliary muscle

Answer 13

muscle in the eye

forms part of the ciliary body

Question 14

Name an alpha1 agonist

Answer 14

Phenylephrine

Question 15

Name an alpha2 agonist

Answer 15

Clonidine

Question 16

Name a beta1 agonist

Answer 16

Dobutamine

Question 17

Name a beta2 agonist

Answer 17

Salbutamol

Question 18

Name an agonist that works on both alpha1 and alpha2 receptors

Answer 18

Methoxamine

Question 19

Name an agonist that works on both beta1 and beta2 receptors

Answer 19

Isoprenaline

Question 20

Name an agnoist compound that work on alpha1, alpha2 and beta1 adrenoreceptors

Answer 20

Noradrenaline

Question 21

Name an agnoist that works on alpha1, alpha2, beta1, beta2 receptors (all 4)

Answer 21

Adrenaline

Question 22

Name an alpha1 antagonist for adrenoreceptors

Answer 22

Prazosin

Question 23

Name an alpha2 antagonist for adrenoceptors

Answer 23

Yohimbine (not in clinical use)

Question 24

Name a beta1 antagonist for adrenoceptors

Answer 24

atenolol

Question 25

Name a beta2 antagonist for adrenoceptors

Answer 25

Butoxamine

Question 26

Name two antagonists that work on both alpha1 and alpha2 adrenoceptors

Answer 26

Phentolamine (competitive) | Phenoxybenzamine (non-competitive)

Question 27

Name an antagonist that works on both beta1 and beta2 adrenoceptors

Answer 27

Propanolol

Question 28

Structural difference between noradrenaline and adrenaline

Answer 28

Same but Adrenaline has a CH3 off the amine group | whereas noradrenaline just has a H atom off it

Question 29

How is adrenaline for cardiopulmonary resuscitation

Answer 29

As an adjunct to cardiopulmonary resuscitation By causing arterial and venous vasoconstriction, adrenaline increases the blood pressure Blood flow in coronary and cerebral arteries is promoted In ventricular fibrillation, adrenaline may coarsen the ECG waveform, and render electrical cardio-version more likely to suceed

Question 30

Name 2 clinical uses of adrenaline

Answer 30

- adjunct to cardiopulmonary resuscitation | - to control anaphylactic shock

Question 31

Name symptoms of anaphylactic shock

Answer 31

- Profound hypotension - Largngeal Oedema - Bronchospasm

Question 32

2 main ways to control anaphylactic shock and how to address it therapeutically

Answer 32

1.Restore blood pressure -Patient with feet raised (supine) -Adrenaline IV (slowly) or IM every 10 minutes alpha1 adrenoceptor activated, vasoconstriction occurs and causes an increase in blood pressure 2. Secure the airway/administer oxygen -Beta2-adrenoceptor -bronchodilation -decrease histamine release

Question 33

Name 2 drugs you would use to control a case of anaphylactic shock

Answer 33

Chlorpheniramine (Slow IV injection) | Hydrocortisone IV

Question 34

How are agonists used to reduce intra-ocular pressure in chronic simple glaucoma?

Answer 34

Adrenaline eyedrops used | They reduce the production of aqueous humor and increase its drainage through the trabecular meshwork

Question 35

How are agonists used alongside local anaesthetics?

Answer 35

Local anaesthetics cause vasodilation and hence facilitate their own redistribution Addition of adrenaline to local anaesthetic causes vasoconstriction (mediated by alpha-adrenoceptors) and prolongs the action of the local anaesthetic and reduces its systemic toxicity

Question 36

When do you avoid use of vasoconstrictors?

Answer 36

Near bases of body appendages and digits

Question 37

What is Phenylephrine used for?

Answer 37

alpha1-selective agonist at adrenoceptors it is used to offset the hypotension attributable to sympathetic block induced by spinal or epidural anaesthesia ALSO: To produce brief periods of mydriasis (pupil dilation) using eyedrops

Question 38

Where is phenylephrine injected for: 1-Spinal anaesthesia 2-epidural anaesthesia

Answer 38

1-injected into subarachnoid space | 2-epidural space

Question 39

What is a Phaeochromocytoma? How is it treated?

Answer 39

Tumour of the adrenal medulla that secretes adrenaline erratically, causing episodes of severe hypertension treated with antagnoists of adrenoceptors: Phentolamine for treatment and Phenoxybenzmine is used during surgery

Question 40

What does Prazosin do?

Answer 40

- dilates arterioles and veins by blocking alpha1 adrenoceptors - used where other therapy has proven ineffective or unacceptable - used also in the treatment of benign prostatic hyperlplasia

Question 41

Unwanted effects of prazosin

Answer 41

``` postural hypotension (fades) retrograde ejaculation (relaxation of bladder neck) ```

Question 42

What is benign prostatic hyperplasia?

Answer 42

Swelling of prostate that districts uretha, resulting in patient being unable to release urine