Reading 3 (Group 1)

Question 1

How many major divisions is the human nervous system divided into? What are they called?

Answer 1

the central nervous system (CNS),
the peripheral nervous system (PNS),
and the enteric nervous system (ENS)

Question 2

What does the CNS consist of?

Answer 2

The CNS consists of the brain and the spinal cord (“backbone”).

Question 3

What does the PNS consist of? What does it connect?

Answer 3

The PNS consists of the nerves going to and from the CNS (a nerve is a bundle of axons). The PNS connects the CNS to muscles and glands, as well as to sensory organs of the body.

Question 4

What does the ENS do?

Answer 4

The ENS regulates motility of the esophagus, stomach, and intestines, as well as the secretion of digestive enzymes and acids.

Question 5

Where are the three main branches of the nervous system situated in the body?

Answer 5

CNS = brain and spinal cord

PNS = cranial and spinal nerve

ENS = digestive tract neurons

Question 6

Which of the three main branches of the nervous system breaks into further branches?

Answer 6

The PNS

Question 7

What are the 2 main branches of the PNS?

Answer 7

the somatic nervous system (SNS)
the visceral nervous system (VNS)

Question 7

Where are the 2 main branches of the PNS responsible for?

Answer 7

SNS = (touch, hearing, etc; muscles that move the body)

VNS = (visceral sensations and control of visceral muscles)

Question 8

Which of the 2 main branches of the PNS branch out into further branches?

Answer 8

both.

Question 9

What are the 2 main branches of the SNS? What is each one responsible for?

Answer 9

The motor (efferent)
- Motor innervation of all skeletal muscles

The sensory (afferent)
- General: Touch, pain, pressure, vibration, temperature; proprioception in skin, body wall, and limbs

• Specialized: Vision, hearing, smell, equilibrium, vision

Question 9

What are the 2 main branches of the VNS? What is each one responsible for?

Answer 9

Motor (efferent) aka autonomic nervous system
- General: Motor innervation of smooth muscle, cardiac muscle, and glands

Sensory (afferent):
- General: Stretch, pain, temperature, chemical changes, irritation in viscera; nausea and hunger

• Specialized: Taste

Question 10

Which of the main VNS branches break off into further branches?

Answer 10

the motor (efferent) aka the autonomic nervous system

Question 11

What are the 2 branches of the autonomic nervous system? What is each one responsible for?

Answer 11

• Sympathetic (fight or flight)
• parasympathetic (calm and connection)