what are the functions of the somatic sensory receptors
Transmit information from the skin such as touch or pain. Also, transmit information from skeletal muscles and joints such as position, movement, and the amount of stretch in muscles (proprioception- monitoring body position)
define:
afferent division
transmits sensory information from receptors to the CNS
what is visceral sensory receptors?
Transmit information from organ systems such as the digestive and respiratory systems. This includes the transmission of information such as stretching, pain, and taste.
what are the sub-structures of afferent division?
somatic sensory receptors
visceral sensory receptors
define:
efferent (motor)division
carries motor commands(response sent) from the CNS to muscles and glands
efferent divison is divided into what 2 systems?
somatic nervous system (SNS) (VOLUNTARY)
autonomic nervous system (ANS) (INVOLUNTARY)
sympathethic and parasympathetic divisons are a part of what system?
the ANS
DEFINE:
Sympathetic division
Allow the body to respond to stress (fight or flight)
ex. increasing heart rate
Define
Parasympathetic division
Opposes the sympathetic division and allows for energy(atp) conservation.
ex. decreasing heart rate
What are the key elements of nerve tissue?
neurons(nerve cells)
neeuroglia(glial cell)
What are the three key parts to typical neuron?
dendrites
soma (cellbody)
axon
What is a Dendrite?
branched structures
receive incoming information (signals)
Soma(cellbody) can be classified as
has a large nucleus
contains many mitochondria, ribosomes, and RER that give the cytoplasm a grainy appearance
what is an axon?
a long structure (tube-like) that may branch resulting in more than one synaptic terminal
the synaptic terminal is the site wher the neuron can communicate with another neuron or cell
What are neurons based on structure?
multipolar neuron
unipolar neuron
bipolar neuron
What are neurons based on function?
sensory neurons
motor neurons
interneurons
What is a multipolar neuron?
consists of two or mor dendrites and a single axon coming from the cell body
this is the most common type of neuron
ALL MOTOR NEURONS ARE MULTIPOLAR
What is a Unipolar Neuron?
The cell body lies off to the side, while the dendrite and axon are aligned in one continous line
MOST SENSORY NEURONS OF THE PNS ARE UNIPOLAR
Describe Bipolar Neuron
Consists of two processes (extensions) from the soma, one a dendrite and the othe an axon
They are found in specialsense organs as thoose for sight and smell
Sensory Neuron is
from the afferent division of the PNS
they receive information from sensory receptors that detect changes in the environment
true/false
sensory receptors may be catergorized based on the information they detected?
true
What are sensory receptors?
EXTERNAL RECEPTORS
detect changes in the surrounding environment such as touch or smell
PRORIOCEPTORS
detect changes in body position/movement of skeletal muscles and joints
VISCERAL SENSORY RECEPTORS
detect changes in organsystems such as the digestive and respiratory systems, and provide info in relation to taste, deep pressure and pain
What are motor neurons?
part of efferent div. of the PNS
transmitt info(commands) from the CNS(control center) to tissues and organs(effectors)
motor neurons may be catergorized based on their target (effector) what are the two types?
somatic motor neurons
visceral motor neurons
somatic motor neurons
neurons of the SNS that intervate skeletal muscles(effector)
What ar visceral motor neurons?
neurons of the ANS that innervate all other tissue and organs including cardiac muscle and smooth muscle
give the classifications of interneurons
located within the brain and spinal cord
connect neurons to one another
they distribute(sort) sensory info
they coordinate motor activity
Where are neuroglia they located and function?
in the CNS and PNS and they provid support and protection for neurons
what are the 4 types of neuroglia in the CNS
astrocytes
oligodendrocytes
microglia
ependymal cells
What are astrocytes
the largest and most numerous of the glial cells
help maintain the blood-brain barrier
classify oligodendrocytes
myelinating cells. their cytoplasmic extensions wrap around axons, forming a myelin sheath that insulates the axon
one oligodendrocyte myelinates segments(internodes) of several different axons
it takes several oligodendrocytes to myelinate one axon
gaps between the myelinated segments are called nodes
myelination of axons increases the speed and efficency at which an action potential (electrical impulse) travels down the axon
microglia
phagocytic cell
protect neural tissue by removing waste and foreign microorganisms
ependymal cells
specicialized type of epithelialcell that produces cerebrospinal fluid(CSF)
line the central canal of the spinal cord and the ventricles of the brain. Where CSF is found
they have cillia to help move CSF around the CNS
What are the neuroglial cells in the PNS
satellite cells
schwan cells
satellite cells
provide support for neurons
What are schwann cells?
myelinate every axon in the PNS
one schwann cells mylenates (internode) only one segment of one axon
many schwann cells are needed to mylenate one axon
gaps between internodes called ondes
increases the speed and effiencency of an action potential