Lecture 7 - Homeostasis

Question 1

Put in order the steps of homeostasis through autonomic nerve function

Answer 1

1. stimulus
2. sensor
3. control
4. effector

Question 2

What is homeostasis?

Answer 2

The ability to maintain a stable interval state that persists despite the change to the outside world

Question 3

What are the subgroups of the autonomic nervous system?

Answer 3

-sympathetic
-parasympathetic

Question 4

What is the neurotransmitter released by the sympathetic autonomic nervous system on the target cell?

Answer 4

norepinephrine

Question 5

What does the ANS control?

Answer 5

-heart rate
-gastric secretions
-respiratory
-body temp
-bp
-vasoconstriction

Question 6

What are the components of an ANS pathway and where are they located? (General)

Answer 6

• cell body (CNS)
• preganglionic neuron (PNS)
• autonomic ganglion
• postganglionic neuron (PNS)
• effector organ

Question 7

What neurotransmitter is released at the autonomic ganglion?

Answer 7

acetylcholine

Question 8

What are the two pathways of the autonomic sympathetic nervous system?

Answer 8

1. • 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)

Question 9

What are the components of the autonomic parasympathetic nervous system?

Answer 9

• 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)

Question 10

What is the parasympathetic “D system”?

Answer 10

-defecation
-digestion
-diuresis

Question 11

What is the sympathetic “E” system?

Answer 11

-exercise
-emergency
-excitement
-embarrassment

Question 12

Where is the origin of the parasympathetic cell bodies?

Answer 12

craniosacral

Question 13

Where is the origin of sympathetic cell bodies?

Answer 13

thoracolumbar

Question 14

What is the importance of the vagus nerve (X)?

Answer 14

-it is 90% of all preganglionic parasympathetic fibers in the body

Question 15

What does the sacral part of the parasympathetic division control?

Answer 15

-large intestines
-urinary bladder
-reproductive organs
-sphincters

Question 16

What are the simple ANS reflexes?

Answer 16

=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

Question 17

What CNS centers control ANS?

Answer 17

=brainstem & spinal cord
-direct effects
-cardiovascular centre in the medulla

=hypothalamus
-integration of ANS

=cerebral cortex
-conscious control over visceral activities

Question 18

Draw out the table

Answer 18

Have fun

Question 19

Axons travelling in the ventral root of the spinal nerves are called what?

Answer 19

pelvic splanchnic nerves

Question 20

Ganglia in the pelvic floor

Answer 20

inferior hypogastric plexus

Question 21

Main differences between somatic and autonomic

Answer 21

=somatic
-one chain
-excite only
-thick and heavy myelinated

=autonomic
-two chain
-excite or inhibit
-thinly myelinated