the nervous system - unit 1

what two parts of the nervous system comprised of?

1. the central nervous system (CNS) - the brain & spinal cord

2. the peripheral nervous system (PNS) - all the nerves in the body

what are nerves?

a bundle of neurones

what are neurones?

cells that carry out information in the form of an electrical impulse called action potential

name the parts of a neurone

1. axon

2. dendrites

3. myelin sheath

4. axon terminal

define axon

a nerve fibre conducting electrical impulses away from the cell body

define dendrites

tree-like structures that receive electrical impulses from other neurones

define myelin sheath

an insulating layer around the axon that speeds up electrical transmission

define axon terminal

at the end of the neurone, transmits signals to other neurones

describe the sensory neurone

• carries action potential from the receptor cells to the CNS

• has short dendrites

• one long dendron

• one short axon

describe a motor neurone

• carries action potential from the CNS to the effector

• one long axon

• many short dendrites

describe the relay neurone

• carries action potential from the CNS to the CNS

• many short dendrites

• one axon

describe the disorders of the nervous system

• when something goes awry with the nervous system, a wide range of problems can occur, collectively known as nervous system disorders/neurological disorders

• these conditions can affect how we move, speak, swallow, breathe, learn and even how we perceive the world around us

• they can also impact our memory, senses and mood - significantly altering a person’s quality of life

neurodegenerative diseases

• involve the progressive degeneration and death of nerve cells over time

• e.g parkinsons, ALS

vascular disorders

• result from problems with blood flow to the brain or spinal cord

• e.g stroke

infections

microorganisms can invade the nervous system, causing inflammation & damage

e.g meningitis

autoimmune & inflammatory disorders

• he body’s immune system mistakenly attacks its own nervous system tissues

• e.g MS (multiple sclerosis)

structural disorders

• involve physical defects or damage to the nervous system

• e.g injury/cancer to rain or spine

developmental & congenital disorders

• conditions present at birth due to abnormal nervous system development

• e.g Spina Bifida

diagnosis & treatment (for nervous system disorders)

• diagnosis involves a thorough neurological examination, imaging tests (MRI/CT scan), electrical tests (EEG for brain activity/ EMG for muscle & nerve function) and sometimes laboratory tests (blood tests, spinal fluid analysis)

• treatment approaches vary greatly depending on the specific disorder & its severity

medications

• to manage symptoms

• to slow disease progression

• to treat underlying causes

• e.g anti-siezure drugs, pain releavers