Nervous System 7

Question 1

The somatic nervous system

Answer 1

Consists of 1 motor neuron that communicates between the CNS and skeletal muscles
- voluntary

Question 2

The autonomic Nervous system

Answer 2

Regulates involuntary activities of smooth muscles, cardiac muscles and glands:
- parasympathetic: promotes maintenance and saves energy
- sympathetic: mobilizes body resources during activities
They mostly act on the same targets(dual innervation) but work in opposition

Question 3

The autonomic motor pathways have

Answer 3

2 motor neurons in series that synapse outside the CNS:
- preganglionic neuron: exits the CNS and goes towards the autonomic ganglion
- post ganglionic neuron: goes to the effector
Like at notes for diagram

Question 4

The Parasympathetic Division(PSNS)

Answer 4

• the rest and digest system
• know ln as the D division: digestion, defaction(poop) and diuresis(pee)

Question 5

The sympathetic division(SNS)

Answer 5

• the flight, fight, freeze system
• known as the E division: excitement, exercise , emergency and embarrassment

Question 6

True or False
The adrenal medulla is considered by some to be a misplaced sympathetic ganglion since embryologically they arise from the same tissue

Answer 6

True
Both develop from the ectoderm

Question 7

Sympathetic features

Answer 7

Origin: Thoracic and lumbar spinal cord
Location of automatic ganglia: close to spinal cord(trunk ganglia)
Preganglionic neurons(length and N.T released): short and ACh
Post ganglion’s neurons(“ “ “): Long and and some E and ACh

Question 8

Parasympathetic features

Answer 8

Origin: brain stem(cranial fibers)
Location of autonomic ganglia: within or near visceral effector organs(terminal ganglia)
Preganglionic neurons( length and N.T. Released): long and ACh
Post ganglionic neurons(“ “): short and ACh
Look at diagrams

Question 9

The dynamic antagonism between these 2 divisions

Answer 9

Maintains homeostasis
Seen in the activities of the heart, respiratory system, and gastrointestinal organs
If the SNS promotes stress response and decreases urination, the PSNS has no response
Look at chart for examples

Question 10

The sympathetic division has sole innervation(No PSNS) in the folllowijg areas

Answer 10

Sweat glands: increases sweating
Arrector pili muscles of the skin: thermoregulation
Kidneys and adrenal medulla: initiates the stress response
Most vascular smooth muscles:
- dilation of blood vessels supplying important organs in fight or flight
- constriction of blood vessels in non-essential organs

Question 11

Efferent neurons

Answer 11

Somatic: myelinated group A fibre
Autonomic:
Preganglionic neuron(thin and myelinated)
Post ganglionic neuron(thin and unmyelinated)