Lecture 7 - Homeostasis Flashcards
Put in order the steps of homeostasis through autonomic nerve function
- stimulus
- sensor
- control
- effector
What is homeostasis?
The ability to maintain a stable interval state that persists despite the change to the outside world
What are the subgroups of the autonomic nervous system?
-sympathetic
-parasympathetic
What is the neurotransmitter released by the sympathetic autonomic nervous system on the target cell?
norepinephrine
What does the ANS control?
-heart rate
-gastric secretions
-respiratory
-body temp
-bp
-vasoconstriction
What are the components of an ANS pathway and where are they located? (General)
- cell body (CNS)
- preganglionic neuron (PNS)
- autonomic ganglion
- postganglionic neuron (PNS)
- effector organ
What neurotransmitter is released at the autonomic ganglion?
acetylcholine
What are the two pathways of the autonomic sympathetic nervous system?
- cell body (CNS)
- short cholinergic preganglionic neuron (lightly myelinated)
- cholinergic nicotinic ganglion (Ach)
- long adrenergic postganglionic neuron (nonmyelinated)
- noradrenaline receptor (a1, a2, b1, b2) on effector organ (NE)
2.
- cell body (CNS)
- short preganglionic neuron (lightly myelinated)
- autonomic ganglion on adrenal medulla (Ach)
- blood vessel
- noradrenaline receptor (a1, a2, b1, b2) on effector organ (NE)
What are the components of the autonomic parasympathetic nervous system?
- cell body (CNS)
- long cholinergic preganglionic neuron (PNS) (lightly myelinated)
- cholinergic nicotinic (Ach)
- short cholinergic postganglionic neuron (PNS) (nonmyelinated)
- muscarinic receptor on effector organ (Ach)
What is the parasympathetic “D system”?
-defecation
-digestion
-diuresis
What is the sympathetic “E” system?
-exercise
-emergency
-excitement
-embarrassment
Where is the origin of the parasympathetic cell bodies?
craniosacral
Where is the origin of sympathetic cell bodies?
thoracolumbar
What is the importance of the vagus nerve (X)?
-it is 90% of all preganglionic parasympathetic fibers in the body
What does the sacral part of the parasympathetic division control?
-large intestines
-urinary bladder
-reproductive organs
-sphincters
What are the simple ANS reflexes?
=baroreflex
-pressure detected in carotid sinus and arch of aorta
-vagus nerve
-if pressure elevates = SA and AV node in heart will decrease pacemaker rates
What CNS centers control ANS?
=brainstem & spinal cord
-direct effects
-cardiovascular centre in the medulla
=hypothalamus
-integration of ANS
=cerebral cortex
-conscious control over visceral activities
Draw out the table
Have fun
Axons travelling in the ventral root of the spinal nerves are called what?
pelvic splanchnic nerves
Ganglia in the pelvic floor
inferior hypogastric plexus
Main differences between somatic and autonomic
=somatic
-one chain
-excite only
-thick and heavy myelinated
=autonomic
-two chain
-excite or inhibit
-thinly myelinated
