nervous system

and Autonomic Nervous systems.

To understand the functions of these components.

To

explain how a nervous impulse is transmitted.

To explain the underlying physiology behind the lesions/damage that occurs in the nervous system.

- sensory perception
- cognitive functions

- motor functions
- regulatory functions

grouped into three basic functions:

- sensory input

- integration of information
- motor output

spinal cord

Peripheral nervous system (PNS), all nervous tissue outside the

CNS

system - electrically excitable

Typically, neuronal structure includes:
cell body
dendrites
axon
synaptic terminals
myelin sheath

axon = axon collaterals
Conduct impulses away from cell body

Dendrites
Usually

many - Highly branched
Receives impulses and conduct impulses towards cell body

the speed of nerve impulses
Gaps in the myelin sheath are

called nodes of Ranvier

contraction
Thalamus: relay center
Hypothalamus: homeostasis
Limbic System: instincts, emotions
Brain Stem: medulla controls

breathing, blood pressure, heart rate

(2000) Principles of Anatomy and Physiology

large part of the peripheral nervous system to the brain.

2)

SC acts as a minor coordinating centre responsible for some simple reflexes (e.g withdrawal reflex).

31 pairs of spinal nerves arise along the spinal cord

The Spinal Cord

Plexuses

12 pairs of Cranial nerves

Autonomic Nervous System

various parts of the
Brain.


Motor

Conduct motor impulses from the brain

to the body via the spinal
Cord.

external environment needed to maintain homeostasis.

e.g. Knee jerk reflex

reflex.
The components of a reflex arc include:

1 -

Receptor - responds to the stimulus.
2 - Sensory neuron - transmits impulse into the spinal cord.
3 - Central Nervous System - the spinal cord processes
information.
4 - Motor neuron - transmits impulse out of spinal cord.
5- Effector - a muscle or gland that receives the impulse from
the motor neuron & carries out the desired response.

attribute to some form of functional loss.
- Paralysis: (loss of motor

function)
- Parasthesias: (loss of senses)
 
The effects of disease or injury upon the CNS and periphery depend on the:
- severity of the damage
- type of neurones involved
- position of neurones involved

Lesions/Damage to the Nervous System

Stroke

- Tumour

- Trauma (caused by a fall or

a blow)

- Multiple sclerosis (destruction of Myelin
sheath)

- Cerebral palsy (defect or injury to the brain that occurs at or shortly after birth)

- Metabolic disorder (interferes with body's ability to maintain itself).

Damage to the Brain

called a ruptured or slipped disk)

- Spondylosis (a

disease that causes stiffness in the joints of the spine)

- Rheumatoid arthritis of the spine

- Neurodegenerative disease (a disease that
damages nerve cells)

- Multiple sclerosis.

to brain.

CVAs often affect the motor cortex and its major

pathways.

These tracts cross in the medulla, therefore:
Left hemiplegia (Stroke on right side of brain)
Right hemiplegia (Stroke on left side of brain)

eye.
Normal response: pupils constrict in response to light stimulus.
Reflex via

autonomic nervous system.
Sensory input of bright light- to brain via optic nerve (II) – parasympathetic impulses out via oculomotor nerve (III) – circular muscles of eye constrict.
Pupil observation important when considering head injury care.

Pupillary Reflex