Nervous System

Question 1

Functions of the Nervous System

Answer 1

Computer system of the body
Coordinates and controls body activity
Detects and processes internal and external information
Formulates appropriate responses

Question 2

3 Types of Neurons

Answer 2

1. Afferent or sensory neurons - carry impulses to the central nervous system (CNS)
2. Associative - transmits impulses from the sensory neurons to the motor neurons
3. Efferent or motor neurons - carry impulses from the CNS to muscles and glands

Question 3

3 Main Parts of the Neuron

Answer 3

1. Soma - also called the cell body
2. Dendrites - each neuron can have 1 or more
   - carry impulses toward the cells body
   - branch extensively
   - combining form is dendr/o
3. Axon- single process that extends out from the cell body
   - can have branches called axon collaterals
   - combining form is ax/o

Question 4

Synapse

Answer 4

The space between 2 neurons or between a neuron and a receptor.
Combining form is synaps/o and synapt/o.
Neurotransmitters are released into the space to allow information to be relayed.

Question 5

Glial Cells or Neuroglia are the supportive cells of the nervous system.

Answer 5

Astrocytes - anchor neurons to the blood supply.
Microglia- work as the first immune defence to the CNS
Ependymal Cells - help circulate the cerebral spinal fluid
Oligodendrocytes - form myelin sheath
Schwann Cells - coat the axon in myelin
Combining form gli/o means glue.

Question 6

Myelin - only covers the axon of the neuron. Myelinated axons have a white appearance which gives the “white matter” in the brain its colour.

Answer 6

is the protective covering over some nerve cells including parts of the spinal cord.
It acts as an electrical insulator. It is interrupted at regular intervals along the length of a fiber by gaps called nodes of Ranvier.
Myelin gives fibres white appearance.

Question 7

Nerve and Nerve Fibres bundle together to form nerves designed to act as a unit to perform specific functions

Answer 7

Nerve fibres aka dendrites and axons are bundled together to form nerves both myelinated and non myelinated.
A nerve may have one or more bundles of impulse-carrying fibres that connect the CNS to other parts of the body.
Combining forms for nerve or nerve tissue are: neur/i and neur/o.

Question 8

Nervous system is divided into 3 parts;

Answer 8

Central Nervous System (CNS)
Peripheral Nervous System (PNS)
Autonomic Nervous System (ANS). - ANS is actually part of the PNS

Question 9

Central Nervous System

Answer 9

Consists of the brain and the spinal cord. It contains both gray and white matter.
The combining form for the brain is encephal/o.
The combining form for the spinal cord is myel/o. (Myel/o also means bone marrow)

Question 10

Peripheral Nervous System

Answer 10

Consists of the cranial and spinal nerves, autonomic nervous system and ganglia.
The cranial nerves are 12 pairs of nerves that originate from the undersurface of the brain.
The spinal nerves arise from the spinal cord and supply sensory and motor fibres to the body region associated with their emergence from the spinal cord.

Question 11

Autonomic Nervous System

Answer 11

Is a part of the peripheral nervous system that innervates smooth muscle, cardiac muscle and glands.
2 divisions of the ANS:
Sympathetic - “flight or fight”
Parasympathetic - maintains normal body function

Question 12

The Brain

Answer 12

The enlarged and highly developed portion of the CNS. Lies within the skull and is the main site of nervous control. The cranium is the portion of the skull that in cases the brain.

Question 13

3 main divisions of the brain

Answer 13

Forebrain
Hindbrain
Brainstem

Question 14

Forebrain

Answer 14

the cerebrum is the largest part of the forebrain and is responsible for receiving and processing information.
Combining form is cerebr/o

Question 15

Hindbrain

Answer 15

The cerebellum is the second largest part that coordinates muscle activity. The combining form is cerebell/o.

Question 16

Brainstem

Answer 16

connects the cerebral hemispheres with the spinal cord and supports basic life functions

Question 17

2 major parts of the Forebrain

Answer 17

1. Cerebrum - motor control
   
   • interprets nerve sensory impulses
   • controls areas of association

Question 18

Diencephelon

Answer 18

Thalamus - occupies the largest area
-controls sensory nerve impulses
-controls some sensations for example, temperature and pain
Hypothalamus 
-regulates body temperature
-fluid control
-sex drives
-influences the pituitary gland

Question 19

Hindbrain (cerebellum)

Answer 19

Controls muscle tone, posture and movement. It is the brain sections that maintains coordination and balance.

Question 20

Brain Stem Consists of:

Answer 20

Midbrain - Central connection centre
Pons - controls the respiration’s centres
Medulla Oblongata - helps to control the heart rate, coughing, respiration rate, sneezing and vomiting.

Question 21

Spinal Cord

Answer 21

Is the continuation of the medulla oblongata in the brainstem. It extends from the medulla oblongata to the lower lumber vertebrae. The spinal column is protected by the spinal or vertebral column. Ascending and descending nerve tracts are housed within the cord.
The combining form for spinal cord is myel/o.

Question 22

Cerebral Spinal Fluid

Answer 22

or CSF is the clear, colourless ultrafiltrate that nourishes, cools and cushions the CNS.
CSF is made by the choroid plexus that lines the ventricles of the brain.

Question 23

Meninges

Answer 23

3 layers that cover the brain and spinal cord. The 3 layers of Meninges are:
1. Dura mater - outer most layer. Hardest toughest and most fibrous.
2. Arachnoid membrane - middle layer. Less dense and web like.
3. Pia mater - innermost layer. Thin and compact and very vascular.
Combining forms for the meninges are: mening/o and meningi/o