11.1 Nervous System Role

Question 1

Your nervous system is active all the time

Answer 1

• It gets information about the depth of your
  breathing, pressure on your skin, temperature,
  light, odours
• It controls muscle movements such as blinking,
  scratching your nose. Memory, language are all
  functions of the nervous system.

Question 2

Parkinson’s disease:

Answer 2

Degenerative disorder of the central nervous
system that often impairs the sufferer’s motor skills and speech.

Question 3

Multiple sclerosis:

Answer 3

Chronic, inflammatory, demyelinating disease
that affects the central nervous system (CNS). Among the
symptoms are changes in sensation, visual impairment, muscle
weakness, depression, difficulties with coordination and speech,
cognitive dysfunction, problems with balance, urinary difficulties,
constipation, sexual dysfunction, spasticity and pain.

Question 4

The CNS consists of the brain and the spinal
cord and acts as a

Answer 4

coordinating centre for
incoming and outgoing information.

Question 4

Case of Genie:

Answer 4

Genie was a young girl who was locked in a small
closet-like room at the age of 18 months. Genie was finally freed
from the closet. She was 13 years old. Although Genie is now an
adult, her language development is quite immature.

Question 5

Vertebrate Nervous System

Answer 5

The nervous system (NS) has two main
divisions:
- Central Nervous System (CNS) and Peripheral
Nervous System (PNS)

Question 6

Nervous System (Contd)

Answer 6

• The PNS consists of nerves that carry
  information between the organs of the
  body and the CNS.
• PNS is further subdivided into somatic
  nervous system and autonomic
  nervous system.

Question 7

Nervous System (contd)

Answer 7

• Somatic NS controls the skeletal muscle, bones
  and skin. Somatic nerves can be either sensory
  nerves (relay info) or motor nerves (generate
  response).

The Autonomic NS controls the internal organs
of the body. The two divisions of ANS are :
- Sympathetic nervous system (fight or flight)
and Parasympathetic nervous system (rest
and digest)

Question 8

Nerve cells

Answer 8

2 diff cells
- Glial
- neurons

Question 9

Glial cells are

Answer 9

non-conducting cells that are for structural support and metabolism for neurons.
- Neurons are the functional units of the nervous system

Question 10

Dendrite

Answer 10

Projection of cytoplasm, carries impulses towards the cell body

Question 11

Axon

Answer 11

Extension of the cytoplasm that carries nerve impulses away from cell body

Question 12

Myelin Sheath

Answer 12

Insulated covering over the axon

Question 13

Axon terminal

Answer 13

Contains synapses, specialized structures where neurotransmitter chemicals are released in order to communicate with target neurons`

Question 14

3 types of neurons

Answer 14

• Sensory
• Interneurons
• Motor neurons

Question 15

Sensory neurons

Answer 15

Efferent neurons
- Relay info from the environment to CNS

Question 16

Interneurons

Answer 16

Link neurons, located in the brain and spinal cord usually; short length

Question 17

Motor neurons

Answer 17

Efferent neurons
- Relay info to the effectors which produce responses

Question 18

Myelin Sheath

Answer 18

• A type of glial cell (support cell) is called the schwann cell
• Schwann cells form the myelin sheath which wrap around axons
• Gaps btwn Schwann cells are called Nodes of Ranvier, (electrical impulses can jump btwn nodes faster)

Question 19

Reflex Arc

Answer 19

• Neural circuit thru the spinal cord that provides a framework for a reflec arc
• Begins with a receptor that relays stimuli to spinal cord. Interneurons in the spinal cord receive info and relay it to motor neurons which activate the effector organs causing a RESPONSE