A&P part 1 Flashcards
What is the nervous system?
A highly specialized system responsible for control and integration of the body’s activities
What is the basic structure of the nervous system?
Divided into the CNS and PNS
What does the CNS consist of?
brain and spinal cord
What does the PNS consist of?
cranial/spinal nerves and the autonomic nervous system
CNS ascending tract?
Carry sensory information from the periphery, muscles, and organs to the higher levels of the CNS
CNS descending tract?
Carry impulses from the brain and result in voluntary muscle movement
How many types of cells are in the nervous system and what are they called?
2
Neuron and neuroglia
What is a neuron?
Primary functional unit of the nervous system.
They do not divide or replace themselves.
Some new neurons may generate from stem cells after a brain injury
What are neuriglia cells?
They are more numerous and are supportive to the neuron.
They can replicate.
When neurons are destroyed, the tissue is replaced by neuroglia cells.
What does a neuron consist of?
A cell body, axon, and several dendrites
What is the cell body?
The metabolilc center of the neuron
What are dendrites?
Short extensions from the body that receive and conduct nerve impulses
What are axons?
Extend varying distances from the cell body and carry nerve impulses. They can be myelinated or unmyelinated.
What is the myelin sheath?
A white lipid substance that insulates and helps conduct the impulses.
Neuroglia cells provide?
Support, nourishment, and protection to neurons. They make up almost half the brain and spinal cord.
What are different types of neuroglia cells and what are their functions?
1) Oligodendrocytes produce the myelin sheath for nerve fibers in the CNS and help make up the “white matter” of the brain
2) Schwann cells myelinate the nerve fibers in the periphery
3) Astrocytes provide structural support to neurons and form the blood brain barrier. They are found in the “gray matter” of the brain.
What is a synapse?
Poijnt at which the nerve impulse jumps from one neuron to another
What is a neurotransmitter?
A chemical agent involved in the transmission of an impulse across this junction
Examples of neurotransmitters
Acetylchonines, epinephrine, norepinephrine, serotonin, dopamine
How are migraines diagnosed?
Two features: Unilateral head pain, throbbing pain, worsense with activity, moderate/severe pain.
And one of these features: N/V, photophobia, phonophobia
What are classifications of migraines?
Aura present
Aura not present
Chronic
What is considered to be chronic migraines?
15 days out of 1 month for 3 months
What are risk factors?
Family Hx
Estrogen and proestrogen
Genetic and environmental factors
What are some examples of triggers?
Fatigue, oversleeping, missed meals, overexertion, weather change, stress, hormonal changes, bright lights, strong smells
Migraine Patho
Change in neurotransmitter levels in CNS. Blood vessel tone.
What is the premonitory phase?
1/3 have fatigue, irritability, loss of concentration, stiff neck, food cravings
What is the migraine aura phase?
Up to 1/3 have aura symptoms lasting up to 1 hour
What is the headache phase?
Throbbing pain, fatigue, N/V, dizziness, hypersensitivity to touch on head. Lasts 4 to 72 hours
What is the recovery phase?
Irritability, fatigue, or depression
