Anatomy and Physiology
NAme the neurotransmitter found at he neuromuscular junction
Acetylcholine
Which enzyme breaks down ACh
Acetylcholinestrase AChe
PNS divides into 2 divisions
Afferent(bring in) Efferent(bring out)
4 types of neurons
Anaxonic bipolar unipolar mulipolar
what Neurotransmitters cause hyper polarization and suppress (decrease likelihood) generation of action potentials
Inhibitory
neuroglandular junction
a neuron which controls or regulates the activity of a secretory cell
what is the difference between a neuromodulator and a neurotransmitter?
a neurotransmitter is substance released by the neuron into the synapse to cause a change in the membrane potential of the postsynaptic cells. A neuromodulator is a small peptide molecule release by the synaptic membrane which may alter the rate of neurotransmitter release or change the response of the postsynaptic membrane to the neurotransmitter
each synaptic terminal i part of a synapse
a specialized site where a neuron communicates with another cell.
sensory neurons
afferent neurons- form the afferent division of PNS deliver info from sensory receptors to CNS
Describe the functions of the afferent and efferent divisions of the nervous system
afferent relays info to CNS efferent relays info from CNS
Name and define the anatomic classification of neurons
anaxonic bipolar unipolar multipolar
interneurons
association neurons outnumber all other neurons most are in brain and spinal cord -distribute sensory info and coordinate motor activity -play a part in higher function
What neuroglia cells in the CNS are responsible for maintaing the blood brain barrier are called
astrocytes
Structure terms of neuron continued
axon- long cytoplasmic propagates electrical signal "action potential" axoplasm- cytoplasm of neuron contains neurotubules and neurofilaments axolemma-outside-surrouds axoplasm initial segment- axon joins cell body at thick region Axon hillock- thick region between body and axon
anaxonic
axons cannot be distinguished from dendrites -in brain and special sense organs
efferent fibers
axons traveling away from CNS
chemical
bind to neurotransmitters
Which neuron is the rarest in the body
bipolar
Afferent Division of PNS
brings sensory info to CNS from receptors in peripheral tissues and organs
Efferent Division of PNS
carries motor commands from CNS to muscles, glands and adipose tissue
Name a describe three types of gated channels
chemical voltage mechanical
Name and define the functions of each type of neuroglial cell
cns -ependymal cells -astrocytes -oligodendrocytes -microglia pns satellite cells schwann cells
""
collaterals- side branches of axon telodendria- fine extensions from axon or collaterals synaptic terminal- end of telodendria "communicate with other cell
What type of integral proteins hold the presynaptic and postsynaptic cell membranes in position
connexons
somatic motor neurons
conscious control over the somatic nervous system
NAme the two types of action potential propagation
continuous and saltatory
somatic nervous system
controls skeletal muscle contractions Voluntary-muscle contractions are under conscious control involuntary SNS is reflex
unipolar or "psuedounipolar"
dendrtites and axons are continuous - most sensory neurons of he PNS are unipolar -long; can reach from toes to spinal cord
what is movement of the transmembrane potential away from resting potential as it becomes more positive
depolarization
visceral motor neurons
do not have conscious control smooth, cardiac glands and adipose tissue
Motor neurons
efferent neurons-carry info from the CNS to peripheral tissue, organ and organ system.
What type of synapses are locked together by gap junctions
electrical
CNS has 4 types of neuroglia
ependymal cells astrocytes oligodendrocytes microglia
ependyma
epithelium of ependymal cells that line central canal and ventricles
oligodendrocytes
myelinate CNS axons; provide structural framework
The communication between cells at the synapse most commonly involves the release of chemicals called
neurotransmitters
What cells for the myelin sheath around CNS
oligodendrocytes
mechanical
open in response to distortion or change in the surface of the cell membrane
voltage-gated
open inresponse to changes in transmembrane potential
What channels are always open
passive and leak channels
synapse involves 2 cells
presynaptic cell- sends a message "includes synaptic terminal postsynaptic cells- receives the message
Exteroceptors
provide info about external environment in the form of touch, temperature, pressure sensations and complex taste, smell, sight, equilibrium and hearing
neurotransmitter
release of chemicals typically from presynaptic cell and dumps into presynaptic cleft
Which is faster
saltatory
PNS Neuroglia
satellite cells schwann cells
What are the 2 ties of PNS neuroglial cells
satellite(astrocytes) Schwann(oligodendrocytes)
afferent fibers
sensory neurons are unipolar neurons
Receptors
sensory structures that either detect changes in the environment(internal or external) or respond to specific stimuli
synaptic cleft
separates pre and post synaptic cells.
The somatic nervous system control what type of contraction
skeletal muscle
define the 2 components of efferent
sns-somatic nervous system-voluntary sans-sensory autonomic nerveous system-involuntary
Which cell membrane channels are important for maintaining resting membrane potential
sodium leak channels, potassium leak channels, sodium potassium ATP exchange pump
What are three post import an voltage regulated channels
sodium, potassium and calcium
central nervous system
spinal cord and brain intergrating, processing and coordinating sensory products and motor commands -coordinates info about balance -higher function-intelligence, memory, emotion and learning
Study guide
study guide
neuroglia (glial cells)
supporting cells, functions essential to the survival of a neuron
schwann cells
surround all axons in PNS; responsible for myelination of peripheral axons; participate in repair after injury
satellite cells
surround neuron cell bodies in ganglia: regular o2 and co2 nutrients and neurotransmitter levels around neurons in ganglia
neuromuscular junction
synapse between a neuron and a muscle
Stimuli which arrive in rapid succession at a single synapse are an example of
temporal summation
neurons
the basic functional units of the nervous system
proprioceptors
monitor the position and movement of skeletal muscles and joints
axoplasmic transport
movement of materials between the cell body and synaptic terminals - travel slow unless there are neurotransmitters
antergrade
movement of materials from cell body to synaptic terminal
retrograde
movement of materials from synaptic terminal to cell body
reflex
movements that happen outside of you awareness
Automatic Nervous System
"visceral motor system"provides automatic regulation of smooth muscle, cardiac muscle, and glandular secretions ANS includes sympathetic and parasympathetic systems.
What does the sodium potassium exchange pump do
-Important for maintaining resting transmembrane potential of cell membrane. Active pump which uses ATP to move ions into and out of cell
Structures terms of neuron
-cell body -perikaryon- cytoplasm -neurofilamnets and neurotubules- in cytoskeleton of perikaryon"structure" neurofibrils-bundles of neurofilaments dendrites- branches, communication
mulitpolar
-most common -have 2 or dendrites but a single axon -all motor neurons that control skeletal muscle are multipolar -long; go from spinal cord to muscles in tips of toes
The sodium potassiumnexchange pump ____sodium ions for every ____potassium ions it brings into the cell
3,2
What is demyelination and how does it affect the nervous system?
Demyelination is loss of myelin surrounding axons. As a result speed of transmission decreases and info will not arrive in a timely manner. Info processing can be effected and prevent coordination of activities
What neurotransmitter causes depolarization and promote generation of action potentials
Excitatory
What is the movement of the transmembrane potential away from resting potential as it becomes even more negative
Hyperpolarization
somatic sensory neuron
monitor the outside world
A neurotransmitter that is widely distributed in the brain and portions of he ANS is
Norepinephrine
Microglia
Remove cell debris, wastes and pathogens by phagocytosis
Why
Saltatory propagation creates a local current which moves very quickly from node to node as a result of the insulation created by the myelin sheath. Te myelin sheath prevents loss of charge through the axolemma and increases speed of transmission
What are the two anatomic divisions of the peripheral nervous system? what parts do they include?
Sensory of afferent division-carries information to the central nervous system motor or efferent division- relay info from CNS to peripheral tissues, including muscles, glands, and other nerves. it is divided into 2 systems
2 systems
Somatic nervous system-vlountary and controls skeletal muscle Autonomic division-controls smooth muscle, cardiac muscle, adipose tissue and glands. Controlled at a subconscious level
bipolar
have two distinct processes -rare -special sense organs relay sight, smell hearing to other neurons
peripheral nervous system
includes all neural tissue outside of the CNS -it delivers info to to CNS - carries out motor commands from CNS
ependymal cells
line the central canal and ventricles of the brain and spinal cord; circulate and monitor cerebrospinal fluid
Astrocytes
maintain blood brain barrier; provide structural support; regulate ion nutrient and dissolved gas concentrations. -absorb and recycle neurotransmitters; form scar tissue after injury fingerlike projections cover capillaries like a blanket
The effects of the neurotransmitter on the post synaptic membrane depends on
many factors, most importantly the properties of the receptor cell membrane
interoceptors
monitor digestive, respiratory, cardiovascular, urinary, and reproductive systems and provide sensation of dissension, deep pressure or pain
visceral sensory neuron
monitor internal conditions
what are the functions of the CNS
to control and perform all communication within the nervous system, including processing of info and control of functions the nervous system integrates incoming stimuli with monitoring and control of internal processes(respiration,cardiac function, digestion, kidney function, and hormonal processes) vital for hemostasis