A & P Introduction to Nervous system Flashcards
List the 3 functions of the nervous system
(1) Sensory (2) Integration and (3) Motor
Describe Sensory from the nervous system
Sensory: detect stimuli
Stimuli can be either:
a) External: originating outside of the body. Examples: a bug
walking across your skin or light entering your eye
b) Internal: originating inside of the body. Examples: change in body
temp or change in amount of CO2 in the blood
Also called: sensory input
Describe Integration form the nervous system
Integration: processes & interprets sensory input.
Process means information is sent to the correct area of the central
nervous system (CNS) For example: sensory information from the eyes is
sent to the visual area of the brain which is in the occipital lobe (as we will
learn next week).
Interprets means to decide if action (response) is needed. Not all stimuli
requires a response, though
Describe Motor from the nervous system
Motor: response to stimuli
Activates effectors organs which can be muscles (smooth, skeletal, or
cardiac) or glands (like the pancreas and salivary glands)
Also called: motor output
Name the two parts of the Nervous system
Central nervous system (CNS) and Peripheral nervous system (PNS)
Describe the Central nervous system
Made of: brain and spinal cord
Functions: Receives sensory input, integrates and processes the
information
Describe the Peripheral nervous system
Made of: nervous tissue outside of CNS which are the spinal nerves,
cranial nerves, and sensory receptors
Functions: detects stimuli, sends sensory input to CNS, and performs the
motor response; Links body to CNS
List and describe the two division of PNS
1) Sensory (afferent) division: takes info from sensory receptors to CNS
2) Motor (efferent) division: takes info from CNS to effector organs
List and describe the 2 parts of motor (efferent) division
1) Somatic nervous system (SNS): voluntary nervous system
Controls: skeletal muscles
2) Autonomic nervous system (ANS): involuntary nervous
system
Controls: smooth muscle, cardiac muscle, & glands. Text
calls this the “visceral motor division”
Define: Sympathetic
Fight or flight system
Define: Parasympathetic
Resting or digesting system
What does generate mean for action potential
Generate means they create the action potential
What does conduct mean for action potential
conduct means they send it along their
membrane & eventually to another cell
Characteristic of neurons
1) Can’t reproduce (cannot undergo mitosis)
2) Have a long life (most nerve cells live as long as you do)
3) High metabolic activity. Need a lot of O2 and energy
4) Limited ability to regenerate (heal). CNS neurons can’t regenerate at all
because they cannot undergo mitosis. PNS neurons can under specific
circumstances but regeneration is often flawed
What are the two parts of neuron
Cell body and Processes
Describe cell body and its function
Cell body also called soma or neurosoma
-the central or “fat” part of a neuron. Contains the nucleus, most of
the organelles, & a lot of cytosol
Function: this is the control center where integration and processing
takes place
In the CNS the cell body is known as
Nuclei
In the PNS the cell body is known as
Ganglia
Describe the Processes and its functions
these project from the cell body. These are also called nerve
fibers. Contain a small amount of cytosol & some organelles
Function: communication. Send information to and from the cell body
Some neurons have their processes in the CNS while others have
them in the PNS
Tract is the process called in which nervous system
Central nervous system
Nerve is the process called in which nervous system
Peripheral nervous system
Name the two types of processes
Dendrites and axon
Define Dendrites and describe its structure and function
Dendrite: is the “receiving end” of a neuron because it receives information
from another neuron or from a sensory organ/receptor
- Function of dendrite: sends this information to the cell body
Info is in form of a graded potential
- Structure of dendrite: short, tapering, & branched.
- A neuron has a lot of dendrites. Having a lot allows it to communicate with a lot of other cells
Define Axon and describe its structure and function
Axon is the “sending end” of a neuron because it sends information to
another neuron or to the effector organ
- Functions of axon: generates AP and conducts the impulse away from the
cell body
-Structure of axon: very long and has few or no branches.
- A neuron only has one axon
Define: neuroglia (glial) cells
these are supporting cells; they provide support and protection to the nerve cells.
What glial cell produce myelin sheath
Oligodendrites
