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