Nervous (module 3) Flashcards
Functions f the nervous system
- Take in info (sensory receptors)
- Analysis of info
- sends response to effectors
- higher cognitive fn (thinking)
Structure of NS
Central Nervous System (CNS): Brain and spinal cord
Peripheral Nervous System (PNS): cranial nerves, spinal nerves
Neuroglia def
helper cells for neurons
Functional divisions
- sensory receptors
- Afferent division
- Info processing in CNS
- Somatic nervous system (PNS)-> skeletal muscle (effector)
- Autonomic nervous system (PNS) -> Parasympathetic and sympathetic:: smooth muscle, cardiac muscle, glands (effectors)
List the structures of the neuron (13)
- dendrites
- cell body (aka perikaryon)
- nucleus
- satellite cells (also nissl bodies)
- axon hillock
- axon
- schwann cells
- mitochondria
- myelin sheath
- neurilemma
- nodes of ranvier
- Axon terminal (telodendria)
- synaptic terminal
- endoneureum
What is neurilemma
outer layer of schwann cells, outside the myelin
Schwann cells do…
wrap around the axon and has myelin (lipid based insulating material) which helps protect and keep charges inside, allowing for the action potential to occur
Action potential general flow
- stimuli received at dendrites or cell body
- impulse initiated at axon hillock
- impulse travels down axon and to axon (synaptic) terminals
Na & K directions
Na in
K out
Unipolar neurons
1 connection to cell body
Bipolar neurons
2 connections to cell body
Multipolar neurons
many connections to cell body, “stereotypical drawing of the neuron”
Synapse def and parts
Synapse is where two neurons have a communication center
- presynaptic membrane
- synaptic cleft
- postsynaptic membrane
- postsynaptic receptors
- synaptic vessels
- neurotransmitters
Neuroglia (6)
- Schwann cells: helper cells, insulate for speed
- Satellite cells: surround cell body, maintain NT levels
- Astrocytes: blood brain barrier
- Oligodendrites: myelinate axons
- Microglia: remove debris
- Ependymal cells: CSF production
Bundle of cell bodies in PNS is called
Ganglion
Bundle of axons in PNS is called
Nerve
Fascicle is
cluster of axons, a single nerve has many fascicles
Nerve components (layers) outer in
- epineurium ‘upon’
- perineurium ‘around’
- endoneurium ‘within’
Multiple sclerosis
an autoimmune disease where T cells attack myelin sheath, scarring it, and ultimately slowing down impulses
Progressive, debilitating
Poliomyelitis
virally infectious, virus attacks neurons, specifically cell body
mostly eradicated
Functions of the spinal cord
impulse condition and reflex integration
Reflex arc (kinds and components)
Monosynaptic: afferent and efferent directly connect
Polysynaptc (interneuron involved)
stimuli > receptor> sensory neuron> Association neuron (interneuron)>motor neuron->effector
List spinal cord structure (in terms of nerves)
- Cervical enlargement
- Intercostal nerves (between ribs)
- Lumbar enlargement
- Conus medullaris
- Cauda equina
- filum terminale
Filum terminale fn
connects the spinal cord to the saccrum