Study guide…part 1 What are the three types of neurons? What is the structure of a neuron? How...
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Study guide…part 1 • What are the three types of neurons? • What is the structure of a neuron? • How does saltatory conduction change the speed of the impulse? • Explain the resting and action potential as they relate to a nerve impulse. • How does the nerve impulse travel across the synapse?
Study guide…part 1 What are the three types of neurons? What is the structure of a neuron? How does saltatory conduction change the speed of the impulse?
Study guidepart 1 What are the three types of neurons? What is
the structure of a neuron? How does saltatory conduction change the
speed of the impulse? Explain the resting and action potential as
they relate to a nerve impulse. How does the nerve impulse travel
across the synapse?
Slide 2
Types of neurons and neuron structure 3 types of neurons:
Sensory Interneurons Motor Neuron structure: Cell body Dendrite
Axon Nodes of Ranvier
Slide 3
The myelin sheath A lipid covering on long axons How does it
affect the speed of the impulse? Saltatory conduction conduction of
the nerve impulse from node to node Let me inflict some pain What
disease results when the immune system attacks this myelin
sheath?
Slide 4
The nerve impulse: Set up the resting potential Resting
potential when the axon is not conducting a nerve impulse More
positive ions outside than inside the membrane -65mV inside the
axon Where is Na+ concentrated? Where is K+ concentrated?
Slide 5
Depolarization A sodium channel opened? What direction would
they move based on their concentration? What direction would they
move based on their charge? How would the charge inside the cell
change?
Slide 6
Repolarization A potassium channel opened? What direction would
they move based on their concentration? What direction would they
move based on their charge? How would the charge inside the cell
change?
Slide 7
The nerve impulse: action potential Action potential rapid
change in the axon membrane that allows a nerve impulse to occur
Sodium gates open letting Na + in Depolarization occurs Potassium
gates open letting K + out Repolarization occurs Wave of
depolarization/repolarization travels down the axon How is the
resting potential restored?
Slide 8
The synapse A small gap between the sending neuron (presynaptic
membrane) and the receiving neuron (postsynaptic membrane)
Transmission is accomplished across this gap by a neurotransmitter
What neurotransmitters do you already know? Where are
neurotransmitters stored?
Slide 9
How does transmission across the synapse occur? Nerve impulse
reaches the axon terminal _________________enter the axon terminal
that stimulate the synaptic vesicles to fuse with the presynaptic
membrane What is the name of this process of exiting the cell?
Neurotransmitters diffuse across the synapse and bind with the
postsynaptic membrane to inhibit or excite the neuron
Slide 10
Study guidepart 2 What are the two parts of the nervous system?
What protects the CNS? Be able to explain the parts of the brain
and their functions. How is the nervous system organized into the
divisions? Contrast the functions of the sympathetic and
parasympathetic divisions. Describe Alzheimers and Parkinsons.
Slide 11
The nervous divisions 2 divisions: Central nervous system
(CNS): Brain and spinal cord Peripheral nervous system (PNS):
Nerves and ganglia (cell bodies)
Slide 12
The central nervous system Consists of the brain and spinal
cord Both are protected by: Bones Meninges 3 protective membranes
that wrap around CNS Cerebral spinal fluid (CSF)
Slide 13
The CNS: Spinal cord Extends from the base of the brain and
along the length of the vertebral canal Functions to provide
communication between the brain and most of the body Can the spinal
cord make decisions?
Diencephalon Includes the: Hypothalamus- Thalamus- Pineal
gland-
Slide 18
Cerebellum Receives and integrates sensory input from the eyes,
ears, joints and muscles about the current position of the body
Functions to: Maintains posture Coordinates voluntary movement
Allows learning of new motor skills (i.e. playing the piano or
hitting a baseball)
Slide 19
The brain stem Includes: Midbrain- Pons- Medulla
oblongata-
Slide 20
The limbic system Joins primitive emotions (i.e. fear,
pleasure) with higher functions such as reasoning Can cause strong
emotional reactions to situations but conscious thought can
override and direct our behavior Includes: Amygdala-
Hippocampus-
Slide 21
The limbic system
Slide 22
The peripheral nervous system (PNS) Includes cranial (12 pr)
and spinal nerves (31 pr) and ganglia outside the CNS - Spinal
nerves conduct impulses to and from the spinal cord - Cranial
nerves conduct impulses to and from the brain Divided into 3
systems: - Somatic - Autonomic - Enteric
Slide 23
The PNS: Somatic division Serves the skin, skeletal muscles and
tendons
Slide 24
The PNS: Autonomic division Regulates the activity of
involuntary muscles (cardiac and smooth) and glands Divided into 2
divisions: Sympathetic Parasympathetic What about enteric?
Slide 25
Health focus: Degenerative brain disorders Alzheimer disease
Usually seen in people after 65 yrs. old Starts with memory loss
Abnormal neurons with plaques of beta amyloid proteins What causes
the plaques? Parkinson disease Usually begins between the ages of
50-60 Characterized by loss of motor control Due to degeneration of
_____________-releasing neurons in the brain