1 Flashcards
What is the cns ? What does it consist of ?
The central nervous system, brain and spinal cord
What is the pns and what does it consist of ?
The peripheral nervous system, all peripheral nerves and all nervous tissue outside of the cns
What is the somatic division?
It controls skeletal muscle contractions and both voluntary and involuntary reflexes
What is the autonomic division?
It controls subconscious actions, contractions of smooth and cardiac muscles, and glandular secretions
What is the site of intercellular communication in the nervous system?
Synapses
Parasympathetic division has what kind of effect?
Relaxing effect
Sympathetic division has what kind of effect?
Stimulating effect
What is the site of intercellular communication in the nervous system?
Synapses
What is the basic functional unit of the nervous system ?
Neurons
What is the location & function of astrocytes ?
CNS & it regulates blood brain barrier (BBB) & repairs damaged nervous tissue
What is the location and function of ependymal cells?
CBS & forms epithelium that lines central canal of spinal cord and ventricles of the brain
- it produces and monitors CSF
Location and function of oligodendrocytes
CNS & many cooperate to form myelin sheath
- it makes nerves appear white
Location and function of microglia
CNS
- smallest and least numerous neorglia
- clean up cellular debris, wastes, and pathogens
Location and function of satellite cells
PNS & surrounds ganglia (clusters of neuronal cell bodies)
- regulates interstitial fluid around neurons
Location and function of Schwann cells
PNS & forms myelin sheath - a Schwann cell can only sheath one axon - many Schwann cells will sheath an entire axon
What are chemically gated channels?
“Key to open lock”
- chemical must be present to open channel
What is a voltage gated channel?
Will open and close if its within a certain range, action potential open ion channels
What are mechanically gated channels?
Physically pressed on the membrane
Know the step to action potential
& LABEL ON GRAPH
Step 1 - depolarization to threshold, action potential is either trigger or not
Step 2- activation of voltage gated sodium channels
Step 3- inactivation of sodium channels and activation of potassium channels
Step 4 - return to resting membrane potential
What ion triggers ACH release ?
Calcium
What are the steps of chemical synaptic transmission?
- arriving action potential depolarizes axon terminal
- membrane opens voltage-gated calcium ion channels & calcium enters the cytosol of the axon terminal
- ACh diffuses across the synaptic cleft and binds to receptors on the postsynaptic membrane. Cation channels open producing graded depolarization due to Na+ inflow
- depolarization ends as ACh is broken into acetate and choline by AChE. Axon terminal reabsorbs chlorine from the synaptic cleft and resynthesizes ACh
What is afferent division ?
Sensory (afferant) carries sensory information
-special sensory receptors : monitor smell, taste, vision, balance and hearing
What is efferent division?
Motor (efferent) : carries motor commands
- from cns to muscles, glands, and adipose tissue (fat)
What composes the posterior root ganglia? What info does it send or receive ?
Axons of sensory neurons & sensory towards brain
What composes the anterior root ganglia ? What infor does it send or receive ?
Axons of motor & involuntary movement to rest if the body
Anatomy of cell body (soma)
-large nucleus and nucleolus
-cytoplasm
-mitochondria
-RER and ribosomes