ANS tutorial Flashcards
What does somatic innervation include
Communication with respiratory muscles
Describe the differences between the sympathetic and parasympathetic nervous system in terms of energy
Sympathetic burns energy
Parasympathetic conserves energy
What is meant by mass activation
Pre-ganglionic neurones can activate a lot of post-ganglionic neurones
Why are parasympathetic nerves more discrete
Because their pre-ganglionic neurones are shorter
What is meant by positively inotropic
increased force of contraction
What is meany by positively chronotropic
Increased heart rate
Where is CAT found
only in cholinergic nerve terminals
Describe some symptoms of increased sympathetic nervous stimulation
Flushings Headache Increased blood pressure Tremor- B2 receptors on skeletal muscle (adrenaline release) Sweating
What is meant by a panic attack
High levels of adrenaline in the bloodstream- anxiety, agitation
Describe clonidine
Partial alpha 2 agonist Reduces sympathetic activity Reduced NA binding Used to treat hypertension Acts on presynaptic receptors
What is a pheochromocytoma
Tumour of the adrenal medulla (Chromaffin cells)
Tends to be benign
Good prognosis- can be removed with surgery
Summarise case 1
§ Tumour in the adrenal gland which affects the chromaffin cells.
§ Adrenaline produced affects:
o Alpha1 receptors on blood vessels and vasoconstricts.
o Beta1 receptors on pacemaker cells in the heart and increases HR.
o Cortisol production (stress) as adrenaline crosses the blood-brain barrier into the hypothalamus.
§ Also affects perspiration by entering the hypothalamus.
o Increased glycogenolysis in the liver and skeletal muscles.
Describe the clonidine test
Clonidine test is a test that stimulates catecholamine production. If these do inhibit the SNS, it’s more likely to be a problem with the PNS.
Describe postural hypotension
Measure BP flat
Measure BP stood
In pathophysiology drop in BP greater than 20mmHg
SNS should correct this
What is light headless a s sign of
Underactive SNS
What is a lack of sweat production due to
Under-active SNS
What is constipation due to
Not optimal PNS- not emptying bladder
What is impaired sexual function caused by
Both SNS and PNS abnormalities
Describe the effects of tumours and Parkinson’s
Tumours- block autonomic outflow in the brainstem
Parkinson’s- reduce autonomic outflow
Summarise case 2
Has postural hypotension and visual disturbances in the visual cortex.
Experiences fait moments when he STOPS walking stopping causes pooling of blood.
After a large meal, blood pools to the gut more postural hypotension.
Alcohol is a vasodilator so will aggravate the postural hypotension.
