BIO
152 - Study Guide – Nervous system
Any material from lecture may be on the exam. It is suggested that you know the lecture material thoroughly.
Any material from Reading
Assignments may also be on the exam.
Neuroanatomy
What are the 2 basic functions of the nervous system?
1. control responses to the external environment
2. maintain homeostasis
What are the 3 overlapping functions of the nervous
system?
1. sensory input
2. integration
3. motor output
Know the 2 main types of different cells in the nervous
system?
1. neurons
2. glial cells
Know the structure of a typical multipolar neuron.
Know the function of each part of the typical multipolar
neuron.
Know the 3 major classes of neurons and their functions.
Sensory, interneurons and motor neurons
Know the different types of supporting cells, where each
is located, and their functions.
Schwann cells – PNS, myelinated
Glial cells – CNS
Astrocytes – form blood-brain barrier
Oligodendrocytes – form myeline sheaths
Know the Major structural divisions of the nervous system
Know the structure of the PNS and CNS
PNS – 12 pairs of cranial nerves, 31 pairs of spinal nerves
- sensory (afferent) system
- motor (efferent) systems
- somatic – reflexes and voluntary control of skeletal muscle
- autonomic - involuntary, visceral functions
parasympathetic
sympathetic.
CNS - Meninges, white matter (myelinated) and gray matter (unmyelinated), cerebrospinal fluid
2 major structures: brain & spinal cord
Neurophysiology
What is an nervous impulse or action potential? What are excitable cells?
- electrical signal propagated along neuronal membranes created by ionic fluxes
What is a membrane potential?
What is a typical value of a membrane potential?
How is the membrane potential created and maintained?
What ions are involved, where are they located and what
are typical concentrations?
Why are membranes selectively permeable? Understand ion channels (including passive and gated) and ion pumps
Know the terms: graded potential, threshold potential, hyperpolarize, depolarize, refractory period, saltatory conduction, nodes of Ranvier, myelin sheath, presynaptic and postsynaptic membranes, excitatory postsynaptic potentials (EPSP) and inhibitory postsynaptic potentials (IPSP), cephaliation, nerve nets and nerve cords
Know the two
types of voltage-gated ion channels
Voltage gates Na channels have 2 gates:
- activation – opens rapidly at depolarization
- inactivation – closes slowly at depolarization
Voltage gated K channels have 1 gate: opens slowly at depolarization
Know the 4 phases of an action potential
1. resting phase
2. large depolarization phase
3. steep repolarization phase
4. undershoot phase
How does the body interpret action potentials?
- they are all or none events, interpreted by frequency of AP
How is an action potential transmitted along an axon?
What 2 factors influence the speed of action potential
transmission?
Diameter and saltatory conduction.
Understand the structure and function of electrical and
chemical synapses.
How does a neurotransmitter conduct a nervous impulse to
a postsynaptic membrane
How do nerve cells integrate the multitude of incoming
nervous impulses?
Excitatory postsynaptic potentials (EPSP) and inhibitory postsynaptic potentials (IPSP)
Summation of EPSP and IPSP
What is summation and what are the two types of summation
Temporal and spatial
What are the different types of neurotransmitters?
1. acetylcholine – inhibitory or stimulatory, depending upon receptor
2. Biogenic amines
- epinephrine, norepinephrine and dopamine from tyrosine
- serotonin from tryptophan
3. amino acids
- glycine, glutamate, aspartate, and gamma aminobutyric acid (GABA)
- GABA most common inhibitory transmitter in brain
4. neuropeptides
- substance P – excitatory signal that mediates pain perception
- endorphins (or enkephalins) - analgesics in brain
What gases are used to signal in the nervous system?
- nitric oxide (NO)
- carbon monoxide (CO)