Finals | Nervous System Flashcards
NERVOUS SYSTEM Main Functions
- Sensory function: detection of internal or external stimuli
- Integrative function: Process sensory information
- Motor function: Elicit an appropriate response
NERVOUS SYSTEM Divisions
CENTRAL NERVOUS SYSTEM
1. Brain
2. Spinal cord
PERIPHERAL NERVOUS SYSTEM
1. Nerves
2. Ganglia
3. Enteric plexus
4. Sensory receptors
PERIPHERAL NERVOUS SYSTEM IS DIVIDED INTO
Somatic Nervous System
Autonomic Nervous System
Somatic Nervous System function
- Allows you to move and control your muscles; Controls voluntary movements
- Feeds information from 4 of your senses: smell, sound, taste, touch
Autonomic Nervous System function
- Controls the unconscious process; involuntary movement (ex. heartbeat, digestion)
AUTONOMIC NERVOUS SYSTEM CAN BE CLASSIFIED INTO
Sympathetic NS
Parasympathetic NS
Enteric NS
Sympathetic NS function
- Fight or flight response
- Controls strenuous bodily functions
Parasympathetic NS function
- Rest or digest response
- Controls basic bodily functions
Enteric NS function
The “brain of the gut,” is involuntary; controls digestion of food
AKA Nerve cells
NEURONS
Neurons vs nerve
Neurons: Nerve cells
Nerve: Collection of neurons
NEURONS Function
Functional unit of nervous system;
Posses electrical excitability
Ability to respond to stimulus and convert in into an action potential.
Electrical excitability
change in the environment
Stimulus
Electrical signal that propagates along the surface of the membrane of a neuron
Action potential
Other term for Action potential
Nerve impulse
PARTS OF A NEURON
- Cell body
- Dendrites
- Axon
Other term for cell body
Perikaryon or Soma
Cell body contains (1) which is surrounded by (2)
- nucleus
- cytoplasm
Cytoplasm of cell body contains
Organelles such as:
1. Lysosomes
2. Mitochondria
3. Golgi complex
cluster of rough endoplasmic reticulum
NISSL BODIES
ENDOPLASMIC RETICULUM produces (1) to (2)
- protein
- replace cellular components
2 cytoskeletons in the cell body
NEUROFIBRIL
MICROTUBULES
NEUROFIBRIL function
provide cell shape and size
assists in moving materials between cell body and axon
MICROTUBULES
receiving or input portion of neuron
DENDRITES
forms a tree shape; the dendrite contains
- Mitochondria
- Nissl bodies
- other organelles
Long, thin, cylindrical projection from the cell body
AXON
AXON Function
Propagates the nerve impulses towards another neuron, muscle fiber, or a gland cell
Cone shape that attaches the axon and cell body
axon hillock
first part of the axon
initial segment
area where nerve impulses arise at the junction of the axon hillock and initial segment
trigger zone
branch of an axon, possibly makes another axon impulses
axon collateral
An axon contains (1), (2), and (3). Because (4) is not present, (5) does not occur in the axon.
- mitochondria
- microtubules
- neurofibrils
- Rough ER
- protein synthesis
The cytoplasm of an axon is specifically called
axoplasm
plasma membrane surrounding the axoplasm
axolemma
end of axon
axon terminal
axon terminal
synaptic bulb
located at the end of the axon terminal
synaptic bulb
releases neurotransmitters
synaptic bulb
membrane enclosed sacs that contains neurotransmitter (contains signals that are sent
synaptic vesicles
has a similar function with the synaptic bulb
varicosities
process of cellular transmission from neuron to muscle, neuron, or gland cell is called
synapse movement
slow axon transport
signal —> dendrites —> body —> axon —> another neuron, muscle fiber (muscle), or gland cell (secretion)
in this type of axon transport, signal transmission can be towards or away from the cell body
fast axon transport
STRUCTURAL CLASSIFICATION OF NEURONS
- Multipolar neuron
- Bipolar neuron
- Unipolar neuron/ Psuedounipolar neuron
Contains several dendrites and one axon
multipolar neuron
multipolar neuron is commonly found in the:
- Brain
- Spinal cord
- Motor neurons
contains one dendrite and one axon
bipolar neuron
Bipolar neurons can be found in the:
- Retina of the eye
- Inner ear
- Olfactory area of the brain
dendrite and axon are fused together to form a continuous process
unipolar neuron (psuedounipolar neuron)
unipolar neuron (psuedounipolar neuron) is commonly found in the:
- ganglia of spinal and cranial nerves
FUNCTIONAL CLASSIFICATION OF NEURONS
- INTERNEURON (MULTIPOLAR)
- MOTOR NEURON (MULTIPOLAR)
- SENSORY NEURON (UNIPOLAR)
functional classification of neuron that receives senses; sensory function
sensory or afferent neuron (unipolar)
receptors of the sensory neuron
- merkel disk
- pacinian corpuscle
- nociceptors
- thermal receptors
- itch receptors
- tickle receptors
touch receptors
meissner corpuscle
merkel disk
pressure receptor
pacinian corpuscle
pain receptor
nociceptor
temperature receptor
thermal receptor
functional classification of neuron that provides action; motor function
motor neuron
functional classification of neuron that processes information; integrative function
interneuron (association neuron)
OTHER CLASSIFICATIONS OF NEURONS (CAN ONLY BE SEEN IN THE CENTRAL NERVOUS SYSTEM)
purkinje cell
pyramidal cell
makes up half volume of the CNS
NEUROGLIA
NEUROGLIA function
Hold nervous tissue together
NEUROGLIA are smaller than (1); (2) times more numerous
- neurons
- 5-25
NEUROGLIA comes from the term
“glue”
NEUROGLIA found in the PNS
- Schwann cells
- Satellite cells
NEUROGLIA found in the CNS
- Astrocytes
- Oligodendrocytes
- Microglia
- Ependymal cells
(1) cells encircle PNS axons. Like (1), they form the myelin sheath around axons
- Schwann
- oligodendrocytes
These flat cells surround the cell bodies of neurons of PNS ganglia
Satellite cells
Maintain blood brain barrier -controlling the levels of neurotransmitter around synapses, -regulate ion, and providing metabolic support.
Astrocytes
Line spinal cord & ventricles of the brain. -involved in producing cerebrospin al fluid (CSF).
Ependymal cells
Myelinate CNS axons, provide structural framework
Oligodendrocytes
Brain’s immune cells -Remove dead cells and pathogens by phagocytosis
Microglia
Surround neuron cell bodies in ganglia. Regulate neurotrans mitter levels
Satellite cells
Myelinate neurons in PNS. maintenance and regeneration of neurons after injury
Schwann cells
