Nervous System and Nervous Tissue

Vocabulary flashcards covering the functional and structural divisions of the nervous system, neuron anatomy and classifications, neuroglial cells, electrophysiology concepts, and neurotransmitter receptor types based on Chapter 11.

Central Nervous System (CNS)

The nervous system division consisting of the brain and spinal cord, responsible for receiving, processing, and responding to sensory information.

Peripheral Nervous System (PNS)

All nerves branching out from the brain and spinal cord (cranial and spinal nerves) that transmit sensory information to the brain and send motor commands to the body.

Somatic Sensory Division

Subdivision of the sensory nervous system that carries signals from skin, fascia, joints, skeletal muscles, and special sense organs toward the CNS.

Visceral Sensory Division

Subdivision of the sensory nervous system that carries sensory signals from internal viscera, such as the heart, lungs, stomach, kidneys, and urinary bladder.

sensory- sends signals

Somatic Motor Division

Subdivision of the motor nervous system under voluntary control that transmits signals to innervate skeletal muscles.

motor-moves

Autonomic Nervous System (ANS)

Involuntary motor division (visceral motor division) that carries signals to cardiac muscle, smooth muscle, and glands to maintain homeostasis.

Effectors

Organs, such as muscles or glands, that carry out the motor effects directed by the nervous system.

Cell Body (Soma)

The most metabolically active region of a neuron that manufactures all proteins needed for the entire cell.

Dendrites

Branched processes of a neuron that receive input from other neurons and transmit electrical impulses toward the cell body.

may contain multiple

Axon

The portion of a nerve cell (nerve fiber) that carries electrical impulses away from the cell body.

Axon Hillock

The region where the axon connects to the cell body, responsible for determining if the neuron will fire an action potential.

Node of Ranvier

Gaps along a myelinated axon that allow for the diffusion of ions.

Myelin Sheath

An insulating layer formed around nerve axons that enables electrical impulses to transmit quickly and efficiently.

Resting Potential

The difference in electrical potential across the plasma membrane when a neuron is not stimulated or is in a state of relaxation.

Action Potential

An explosion or impulse spike of electrical activity generated by a depolarization current that travels down an axon away from the cell body.

Channel-linked Receptors

Neurotransmitter receptors that act directly to open ion channels, resulting in fast-paced electrical movements.

G-protein Coupled Receptors

Neurotransmitter receptors that act indirectly through intracellular pathways, resulting in slower, longer-lasting effects.

functions of nervous system and tissue

controls perception, transmits signals, directs voluntary movement , regulates homeostasis, works w endocrine system

what it regulates in homeostasis

respiratory rate, bp, body temp, sleep and wake cycles, PH levels

sensory somatic

carrry signals from skeletal bones , muscles, joints and skin

hearing, vision, taste, smell, balance

visceral sensory

transports from viscera(heart, lungs, kidneys, bladder, stomach)

affrerent

going towards CNS

cell body is also called

soma

integrative functions

ability to interpret and understand rapid change

99% we ignore, remaining leads to motor response

motor functions

actions that cause movement= think, feel, learn

carry from brain to spinal cord

efferent

exiting away from cns

somatic motor

transmits to skeletal muscle

VOLUNTARY

ANS(autonomic or visceral nervous system)

neurons carrys signals to thoracic or abdomen, critical for maintaining homeostasis

regulates secretion of certain glands, contraction of smooth & cardiac muscle

INVOLUNTARY

somatic & visceral > sensory

skeletal and skin

stomach and urinary

somatic & visceral > motor

skeletal muscle

cardiac & smooth

neurons

cells that transmit signals

cell body of neuron

metabolically active

manufactures proteins

3 main regions of neuron?

receptive, conducting, secretory

receptive

dendrites and cell body

conducting

axon

secretory

axon terminal

neuroglia

-Smaller in size than a neuron

-Constitute half of the CNS volume

-Do not generate action potentials

-Can multiply and divide within a mature nervous system

-Help support, nourish and protect neurons

-Aide in homeostasis of the intestinal fluid that surrounds the neurons

4 types of neuroglia in CNS

-Astrocytes

-Oligodendrocytes

-Microglia

-Ependymal Cells

2 types of neuroglia in PNS

-Schwann Cells

-Satellite Cells

astrocyte

• anchors neurons and blood vessels

• repairs damaged tissue

• regulates extracellular environment

• facilitate formation of BBB

oligodendrocyte

myelinate certain axons in the cns

microglial cell

act as phagocytes

ependymal cell

line cavities

cilia circulate fluid around brain & spinal cord

some secrete fluid

schwann cell

myelinate certain axons in the PNS

satellite cell

surround and support cell bodies

regeneration of damages tissue

nearly nonexistent in CNS
limited in PNS

neural tissue can regenerate only if cell body remains intact

electrophysiology of neurons

• excitable in presence of stimuli

• neurons are how our bodies send and receive messages

neurons at rest?

• thin layer of NEGATIVELY charged ions exists in the cytosol on INSIDE of cell

• - thin layer of POSITIVELY charged ions exist OUTSIDE of cell

sodium and potassium are?

critical components of neuron functionality

resting potential

difference in electrical potential across the plasma membrane when the cell is not stimulated or when the cell is in a state of relaxation

action potential

describes when a neuron sends information down an axon, away from the cell body.

It is described as a spike or impulse explosion of electrical activity that is created from a depolarization current

neurotransmitters

chemicals that allow neurons to communicate w each other thru out the body

-carry chemical signals from neuron to next nerve cell(can be a nerve cell, muscle cell, or gland)

examples of neurotransmitters & functions

serotonin, dopamine, adrenaline, glutamate

regulating appetite, sleep-wake cycle, mood regulation

neurotransmitters (classified by function)

excitatory vs inhibitory

causes either depolarization or hyperpolarization of ions

neurotransmitters (classified by function)

direct vs indirect

direct bind to and open ion channels, where as indirect causes longer-lasting effects by passing through intracellular pathways

neurotransmitters (classified by receptors)

channel linked receptors

direct action, fast paced movement

neurotransmitters (classified by receptors)

g protein copied receptors

indirect slow movements