Ch8 Nervous System Flashcards
Division of nervous system
Central-brain and spinal cord
Peripheral-cranial and spinal nerves
Function of Nervous system
Coordination and control of body
Detect changes
Organize info
Somatic
Skeletal
Autonomic
Smooth muscle
Cardiac muscle
Glands
Structure of neuron
Cell body-nucleus and organelles
Dendrites-receive impulses,carry impulses to cell body and axon
Axon-long,thin, carry impulses away from cell body or dendrites
Myelin sheath-insulates axons,increases speedof impulse transmission
Nodes of ranvier lack myelin and are placed where axon is exposed
3 types of neurons
Sensory
Interneurons
Motor
Neuroglia
Support and protect neurons
More numerous than neurons
Neuron characteristics
Irritability-respond to stimulus by forming impulse
Conductivity-transmit impulse along neuron to another cell
Resting potential
Na+ outside
K+,po4-3,so4-2 inside
Polarized
Impulse formation
All or none response
Threshold stimulus
Needed to activate neuron
When activated by stimulus
Na+ in Positive and negative equal on both sides of membrane Depolarized-action potential 3so 2pin
Repolarization
K out
Na out
K+ in to reestablish resting state
Impulse conduction
Impulses only form in membrane exposed at nodes of ranvier
Synapse
Junction of axon with another neuron
Meninges
Three fibrous membranes
Separate cns and bone
Protect brain/spine
Csf- cerebrospinal fluid
Shock absorber for brain
4 major parts of brain
Cerebrum
Cerebellum
Diencephalon
Brain stem
Cerebrum
Largest part of brain Sensations Voluntary actions Reasoning Planning
Left side of brain
Analytical
Right side of brain
Musical
Diencephelon
Thalamus
Hypothalamus
Hypothalamus
Controls pituitary gland
Homeostasis
Limbic system
Thalamus and diencephelon
If malfunctions it can result in mood disorder