anatomy and physiology - nervou system

u6, p1

what cell makes up 10% of the nervous system

neurons.

what is the function of the neuron cell

conducts impulses around the body.

what is the function of the neuroglia cell

supports, insulates, and protects neurons.

what cell makes up 90% of the nervous system

neuroglia.

what organs make up the cns

the brain and spinal cord.

what organs make up the pns

the cranial and spinal nerves.

afferent division of the PNS

the sensory division.

efferent division of the PNS

the motor division.

what is the function of the sensory/afferent division of the PNS

sends impulses from the senses to the CNS + sends impulses towards the CNS,

what is the function of the motor/efferent division of the PNS

sends impulses from the CNS to the muscles and glands.

autonomic nervous system performs ___ muscle control

involuntary

somatic nervous system performs ___ muscle control

voluntary

sympathetic division

"fight" or "flight" responses, used in emergency situations like: seeing a bear

parasympathetic division

"rest" and "digest" responses reduce sympathetic functions, provides us with resting responses, such as digestion and urination.

neuroglia in the cns

astrocytes, oligodendrocytes, microglia, ependymal cells.

neuroglia in the pns

satellite cells and schwann cells.

astrocyte

supports and anchors neurons to surrounding capillaries.

microglia

provide immune response to CNS.

ependymal cells

secretes and circulates cerebrospinal fluid.

oligodendrocytes

provides myelin insulation to neurons in the CNS.

satellite cell

supports and anchors neurons in the PNS.

schwann cell.

provides myelin insulation to neurons in the PNS.

neuro-

nerve.

polar-

end.

dendr-

tree like.

auto-

self.

gli-

glue.

astro-

star.

oligo-

few.

what types of ions are brought by the sodium potassium pump?

2 K+ ions into the cell, 3 Na+ ions out of the cell.

if a stimulus causes the membrane potential to reach the threshold of ___, the action potential will occur.

-55 mV.

where 2 neurons meets =

a synapse.

the space between two meeting, non-touching neurons is called a ___.

synaptic cleft

what is an action potential

the stimulation of a neuron by the environment/another neuron, causing sodium to rush into the neuron and reverse the change --> depolarization.

what is a nerve impulse?

an electrical signal traveling along a neuron.

resting potential:

the intracellular space = (-), extracellular space = (+).

all-or-none phenomenon

impulse must reach -55 mV. if not reached, the stimulus = a false alarm, and the neuron returns to resting state. it's either fire or no fire.