chapter 3 Flashcards
CNS
the division of the nervous system located within the skull and spine
PNS
the division located outside the skull and spine
Somatic nervous system
part of the PNS that interacts with the external environment
composed of afferent and efferent neurons
Autonomic nervous system
part of the peripheral nervous system that regulates the body’s internal environment
Afferent Nerves
carry sensory signals from the skin,skeletal muscles,joints,eyes,ears and so on
Efferent nerves
carry motor signals from the ventral nervous system to the skeletal muscles
Sympathetic nervous system
sympathetic nerves stimulate,organize and mobilize energy resource in threatening situations
fight or flight
Parasympathetic Nervous System
autonomic target organ receives opposing sympathetic activity
changes are indicative of psychological relaxation
Meninges: Dura,Pia, Arachnoid
Protective membranes
Dura - tough membrane
Arachnoid - fine spider-web-like membrane
Pia - delicate , which adheres to the surface of the CNS
Cerebrospinal fluid (CSF)
also protecting the CNS
fills the subarachnoid space, the central canal of the spinal cord and the cerebral ventricles of the brain
cerebral ventricles (lateral, 3rd, 4th)
four large internal chambers of the brain
the two lateral ventricles
the third ventricle and the fourth ventricle
cerebral aqueduct
connects the third and fourth ventricles
choroid plexus
networks of capillaries, or small blood vessels that protrude into the ventricles from the pia mater
cerebrospinal is produced
neurons
cells that are specialized for the reception,conduction and transmission of electrochemical signals
glial cells
Any of the cells that hold nerve cells in place and help them work the way they should.
oligodendrocytes
glial cells with extensions that wrap around the axons of some neurons of the central nervous system
- CNS
Schwann Cells
performed in the peripheral nervous system
each Schwann cell constitutes one myelin segment
wrap around with myelin
astrocytes
largest glial cells
extensions of some astrocytes cover the outer surfaces of blood vessels that course through the brain
play a role in allowing the passage of some chemicals from the blood into CNS neurons and blocking other chemicals
they have the ability to contract or relax blood vessels based on the blood flow demands of particular brain regions
microglia
smaller than other glial cells
respond to injury or disease by multiplying, engulfing cellular debris or even entire cells and triggering inflammatory responses
nuclei ganglia
in CNS
clusters of cell bodies
Ganglia
in the PNS
clusters of cell bodies
tracts/nerves
anterior
towards the nose end
posterior
toward the tail end
dorsal
toward the surface of the back or the top of the dead
ventral
toward the surface of the chest or the bottom of the head
medial
toward the midline of the body
lateral
away from the midline toward the body’s lateral surfaces
superior
above
towards the head
inferior
below
towards the ground
proximal
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