Nervous System Flashcards
The study of the nervous system is known as
Neurology
Nervous system works with…..
The endocrine system to maintain homeostasis (body balance
Two parts of the Nervous System
Central Nervous System
and
Peripheral Nervous System
Central Nervous System is made of…
The brain and spinal cord
Peripheral Nervous System is made of…
12 pairs of cranial nerves arising from the brain and 31 pairs of spinal nerves arising from the spinal cord
Sympathetic function
Accelerates body processes and regulates involuntary activities of smooth and cardiac muscle
Parasympathetic function
Slows down body processes
3 Types of Nerves
Sensory nerve / neurone
Motor nerve / neurone
Mixed nerve /neurone
Function of Sensory nerve / neurone
Carry sensory impulses from the sensory organs to the brain and spinal cord. They convey sensations of pain, temperature, taste, smell etc
Motor nerve / neurone
Carry motor impulses from the brain and spinal cord to muscles and glands. They initiate the contraction of muscles and the action of glands.
Mixed nerve /neurone
Carry both sensory and motor nerve fibres. The only place mixed nerves are found in the body is in the brain and spinal cord as cranial and spinal nerves
Neurone structure
They have a cell body one long nerve fibre called the axon and several small nerve fibres called dendrites.
Axons
Carry impulses away from the cell body
Dendrites
Carry impulses towards cell body
A synapse
The point where two neurones connect or where a neurone connects with its muscle fibre
Myelin Sheath
Insulates the axon and protects it from pressure and helps speed up nerve conduction
Neurilemma
Surrounds the myelin sheath and helps regenerate the nerve cell
Grey matter
Outside of the brain and the inside of the spinal cord
White matter
Inside of the brain and the outside of the spinal cord
Nodes of Ranvier
Gaps in the myelin sheath which speed up the passage of nerve impulses
Functions of the Cerebrum
Mental activities, memory, intelligence
Interpreting sensations like pain, heat and cold
Initiating and controlling voluntary muscle action
Functions of the Cerebellum
It is associated with maintaining balance, posture and muscle tone.
Ensures movements are smooth and co-ordinated
Hypothalamus location
Situated deep within the cerebrum at the top of the brain stem with the pituitary gland attached to its base
Functions of the hypothalamus
Regulates body temperature, water and metabolism
Centre for drives of emotions such as thirst, appetite, sex, pain and pleasure
It also regulates the pituitary gland
Pons varolii function
Acts as a link between the 2 hemispheres of the cerebellum and the spinal cord by transmitting impulses.
Medulla Oblongata location
Lies between the pons varolii and the spinal cord
Functions of the Medulla Oblongata
Controls the involuntary actions of the respiratory, cardiac, vasomotor and reflex centres i.e. breathing rate and heart rate
How many spinal nerves
31 pairs of spinal nerves
What is the Reflex Arc?
A complete pathway through the nervous system from stimulus to response.
Autonomic Nervous System
supplies nerves to all the internal organs of the body which are not under our conscious control e.g. heart muscle, smooth muscle of hollow organs
What controls the ANS?
Controlled by the hypothalamus in the cerebrum, which receives impulses from the Central Nervous System.
NEURITIS
Inflammation of a nerve, caused by infection, injury, poison, etc. Effect: pain along the nerve’s length and/or loss of use of the structures supplied by the nerve
BELL’S PALSY
Injury or infection of the facial nerve which subsequently becomes inflamed
NEURALGIA
Burning or stabbing pain along the course of one or more nerves.
SCIATICA
Pressure on the roots of the sciatic nerve often caused by degeneration of an intervertebral disc
PARKINSON’S DISEASE
Progressive disease caused by damage to basal ganglia of the brain and resulting in loss of dopamine (neuro-transmitter)
MULTIPLE SCLEROSIS (also known as disseminated sclerosis)
Loss of the protective myelin sheath from nerve fibres in the central nervous system
CEREBRAL PALSY
Damage to the brain, caused during birth or resulting from a pre-natal defect
MOTOR NEURONE DISEASE
A rare progressive disorder, in which the motor neurones in the body gradually deteriorate
MYALGIC ENCEPHALOMELITIS (ME)
Also known as post-viral fatigue or chronic fatigue syndrome
