Nervous system Flashcards
(34 cards)
Nervous system is divided into
Central nervous system & Peripheral nervous system
Central nervous system is composed of
Brain & Spinal cord
Peripheral nervous system is composed of
Cranial & Spinal nerves
Functionally the peripheral nervous system is divided into
Sensory (afferent) neurons that bring information to the CNS & Motor (efferent) neurons that carry information away from the CNS.
Special sensations include :
Vision, Hearing, Smell, Taste
Superficial Sensations :
From Skin ;
as Touch, Temperature, Superficial pain, Pressure
Deep Sensations :
From Muscles, Bones, Joints ;
as Proprioception, Deep pain
Visceral sensation :
From viscera ;
as Visceral pain
Somatic neurons control
Skeletal muscles
Autonomic neurons control
Cardiac muscles, Smooth muscles, glands
Complex network of nerve cells called
Neurons
Neuron has a _____, _____ to receive incoming signals
Cell body (soma)
Dendrites
Name the part of neuron that responsible for electrical signals transmission
Axon transmit signals to axon terminal
Small non-insulated areas called
nodes of Ranvier
Myelin sheath acts as
insulator
Myelinated nerve fibers axons :
formed by :
Axons surrounded by myelin sheath which is formed by Schwann cells
Unmyelinated nerves fibers:
Axons not surrounded by myelin sheath
Nerve excitability is the ability of living cells to
respond to stimulus
Excitability depends on
membrane potential
The average value for RMP of neurons is
-70 mv
-70 mv of RMP results from
selective permeability of membrane & Na+K+ pump
Na+K+ pumps
3 Na+ ions out & 2 K+ ions in
Action potential is rapid change in
membrane potential
Depolarization starts slowly then rapid once it reaches :
and continues until reaches :
-55 mv
+30 mv
