Neuronal communication Flashcards
(64 cards)
what is coordination in the body required for?
- body systems to continue its function as most of the body cannot work in isolation
- homeostasis
- cell signalling
what is a stimulus?
any change in the environment of an organism that causes a response
- can be internal or external environment
what is a receptor?
a cell which detects a stimulus
what do receptors do?
convert energy from one form to another
- they are specific to the type of light energy they receive and then convert
where is the Pacinian capsule found?
in the skin dermis and in abundance in fingers and soles of feet
what does the Pacinian do?
detects mechanical pressure
what is an effector?
a muscle or gland that brings about a response
what is a response?
the change that occurs because of initial stimulus
what does the central nervous system consist of?
brain and spinal cord
what is the peripheral nervous system?
sensory and motor neurones connecting CNS to sensors and effectors around the body
what is a reflex?
fast, automatic response to a stimulus. it does not involve conscious thought
what are the three types of neurones?
- sensory neurones
- relay neurones
- motor neurones
where do sensory neurones go between?
impulses from receptor to relay neurone/CNS
where do relay neurones go between?
impulses from sensory to motor neurones
where do motor neurones go between?
impulses from relay/CNS to effector
what do dendrites do?
connect to other neurones
what are key features of neurones?
- long
- voltage gated ion channels in the cell surface plasma membranes
- sodium potassium pumps in the cell surface membrane
- have a myelin sheath
what is a cell body?
contains nucleus and produces neurotransmitters
where do dendrons go between?
to cell body and axon away from cell body
what is myelination?
a fatty sheath around a neurone
what do myelination consist of?
many layers of the plasma membranes of schwann cells
what does myelination do?
- insulates the neurone
- increases the speed of action potential
what is a myelin sheath?
a series of schwann cells wrapped in layers around the axon
what are nodes of ranvier?
gaps at intervals along the neurone