Lecture 31 - Nervous System Introduction Flashcards
What are the 3 main functions of the nervous system?
- sensory input
- integration
- motor output
Functions that can be controlled voluntarily are referred to as _____ and those that are involuntary are referred to as _____
somatic; autonomic
What two parts is the nervous system divided into? what do they encompass?
- Central (CNS) - brain and spinal cord
- Peripheral (PNS) - cranial nerves, nerves extending away from CNS
What are the two functional divisions of the PNS
- sensory (afferent)
- motor (efferent)
what are the two divisions of the efferent PNS
- somatic
- autonomic
the sensory (afferent) division conducts impulses from ____ to ____
receptors; CNS
think “arriving”
the motor (efferent) division conducts impulses from ____ to ____
CNS; muscles/glands
think “exiting”
the somatic system conducts impulses to what kind of muscle
skeletal
the autonomic system conducts impulses to what kind of muscle
cardiac + smooth
T/F: the parasympathetic division conserves energy
TRUE
where are afferent neurons located in regard to the spinal cord
outside
where are efferent neurons located in regard to the spinal cord
within ventral horn
where is the enteric system found
within the walls of the entire gastrointestinal tract
Myenteric plexus
found in muscularis externa of GI
Submucosal plexus
found in submucosa of GI
What are the two types of principal cells
- Neuroglia
- Neurons
Neuroglia (glial cells)
small cells that surround and wrap delicate neurons
Neurons (nerve cells)
excitable cells that transmit electrical pulses
Astrocytes
most abundant
cling to neurons, synaptic endings, capillaries
summarize the functions of:
astrocytes
- support + brace neurons
- exchange between capillaries and neurons
- guide the migration of young neurons
- control chemical environment
- respond to nerve impulses
- influence neuronal functioning
- information processing
- maintain blood-brain barrier
Microglia
small ovoid cells with thorny processes that touch/monitor neurons