CNS and PNS

Question 1

nervous system overview

Answer 1

• works with the endocrine system
• the nervous system is the system of the body that sends information in response to information received from the environment

the nervous system is composed of 3 functional subsystems:
- centeral nervous system
- peripheral nervous system

a nertwork of billions or trillions of nerve cells linked together in a highly organized manner to form the rapid control system of the body

Question 2

CNS and PNS composition

Answer 2

The central nervous system (CNS) is composed of the brain and spinal cord

The peripheral nervous system (PNS) is composed of peripheral nerves

Question 3

Input to CNS

Answer 3

sensory receptors to the afferent system (into), this is the input to the CNS

happens in PNS

Question 4

output from CNS

Answer 4

Brain and spinal cord to the efferent system (out).
The efferent system is split into the somatic and autonomic system

Question 5

somatic system

Answer 5

peripheral nervous system:
- somatic is voluntary, such as taking notes when something is said
- message goes to skeletal muscles

Question 6

autonomic system

Answer 6

autonomic system: involuntary, such as digestion and breathing.

sympathetic –> prepares the body stress and action (fight or flight)
parasympathetic –> at rest and digest

• goes to smooth muscles, glands

Question 7

Nervous System Cells

Answer 7

Main cells of the nervous system are: neurons and glial cells

Both found through the nervous system

Question 8

Neurons

Answer 8

The functional units of the nervous system

They conduct nerve impulses

Specialized nerve cells are categorized into three (3) groups:
- Sensory (afferent) neurons → send the message to the brain
- Interneurons → present in the brain and the spinal cord → come up with the message
- (spinal cord has interneurons
- reflex arch → message goes to SPINAL CORD and the message gets relayed here. )

Motor (efferent) neurons → send the message

Question 9

motor efferent neuron and sensory afferent neuron

Answer 9

• form fits function, they are different shapes for their function

Question 10

Interneurons

Answer 10

Interneurons integrate and interpret the sensory information and connect the sensory neurons to outgoing motor neurons

efferent to afferent neuron, almost liek the middle man

Question 11

Glial Cells

Answer 11

think of a wire, the electrical signals will not get lost because they are protected.

Provide nutrition and support to neurons

Schwann cells form tight layers of plasma membrane known as myelin sheaths

The electrical impulses jump between the myelin sheath to speed up the rate of conduction

• myelin sheath speeds up the rate of conduction