Week 9: Nervous System Flashcards
How fast can impulses be sent out in the body?
130 meters a second
How are nerves stimulated?
Changes in internal/external environment
What are the functions of the nervous system
- sensory
- integrative
- motor
What does the sensory function of the nervous system do?
It senses change
What does the integrative function of the nervous system do?
It analyses sensory information, stores information and makes decisions
What does the motor function of the nervous system do?
It responds to stimuli by muscular contraction and glandular secretions
What are the two routes of the nervous system?
Sympathetic and parasympathetic
What does the sympathetic pathway mean?
Fight or flight
What does the parasympathetic pathway mean?
Peacemaker, rest and digest
What happens within a sympathetic nervous system?
Neurones convey impulses from their origins in the hypothalamus, reticular formation and medulla oblongata to effector organs/tissues
What are adrenal glands stimulated to release?
Adrenaline/nor-adrenaline
What happens within a parasympathetic nervous system?
Two neurones are involved in the transmission of impulses from their source to the effector organ with the neurotransmitter being acetylcholine at both synapses
What are the 2 main types of nerves?
Sensory and motor
What are afferent nerves?
- sensory nerves
- receive information
- transmit sensory information gathered from the skin, muscles and joints to CNS
What do efferent nerves do?
- motor nerves
- send information on
- carries information from the CNS out to the muscles and glands
What are the 2 properties of neurones?
- Irritability
- Conductivity
What is irritability?
The ability to initiate impulses in response to stimuli from outside and inside the body
What is conductivity?
Ability to transmit an impulse
What do Schwann cells produce?
Myelin
What is white matter?
- is found deeper in tissues of the brain
- contains nerve fibres which are extensions of nerve cells
- myelin gives white matter its colour
What is grey matter?
- grey matter makes up the outermost layer of the brain
- it gets its colour from the high conc of neuronal cell bodes its contains
- grey matter contains unmyelinated axons
What happens when the impulse reaches the end bulb?
Calcium ions enter the bulb from interstitial fluid attracting synaptic vesicles to the plasma membrane
What do neurotransmitters do?
Diffuse across synaptic cleft and act on receptor sites of post synaptic membrane, changing permeability of membrane to sodium ions, and stimulating depolarisation
