Nervous System

Nervous system

master control and communication system of the body

nervous system

uses electrical impulses for communication

neurology

study of the nervous sytem

sensory function

it is a FUNCTION OF THE NERVOUS SYSTEM that when the sensory receptors detect internal or external stimuli then make a sensory input

sensory input

it is the outcome when sensory receptors detect internal or external stimuli

Integrative function

a FUNCTION OF THE NERVOUS SYSTEM that processes sensory information to make appropriate responses

Motor Function

a FUNCTION OF THE NERVOUS SYSTEM that activates effectors such as muscle contraction or gland secretion via motor output

Motor output

used by motor function to activate effectors

Central Nervous System

it is a system of the brain and spinal cord, it integrates and is the command center

Peripheral Nervous System

it is a system that is outside the CNS

spinal nerves

carries impulses to and from the spinal cord

cranial nerves

carry impulses to and from the brain

Sensory or Afferent Division

a functional classification that convey impulses to the CNS

somatic nervous system

it allows voluntary control of the skeletal muscles

autonomic nervous sytem

it regulates automatic or involuntary effect

astrocytes

it is a neuroglia in the CNS that is most numerous , star shaped and maintains the blood brain barrier. it is also associated with learning and memory as well as it maintains appropriate chemical environment for generation of nerve impulses, 

oligodendrocytes

it is responsible for forming myelin sheath around the axons of the neuroglia in CNS, can myelinate several axons

microglia

it is derived from macrophages and removes cellular debris as well as it phagocytize microbes and damaged nervous tissue

ependymal cells

it is a cuboidal to columnar cells in a single layer that lines the ventricles of the brain and the central canal of the spinal cord, it also produces cerebrospinal fluid (csf)

schwann cell

it forms the myelin sheath around the axons in the PNS and can only myelinate a single one

satellite cell

it surround the cell bodies of the PNS neurons and provides structural support as well as regulate exchange of neuronal cell bodies and interstitial fluid

Neurons

also called as nerve cells that is specialized to transmit impulses from one part of the body to another

cell body

the metabolic center of the neuron that has a transparent nucleus with a large nucleolus and contains the usual organelles but without the centrioles

Nissl bodies

responsible for protein synthesis to regenerate and maintain the cell, it has composed of the rough ER and ribosomes

neurofibrils

found within nerve cells that form a network in the cell body and extend into processes, consists of the intermediate filament

dendrites

it conveys incoming messages toward the cell body

axon

generates nerve impulses and conduct them away from the cell body

axon hillock

it arises from the axon’s cone-like region

Axons

forms hundred to thousands of axon terminal which contains neurotransmitters

Synapse/Synaptic Cleft

the tiny gap between two neurons (the axon terminal and dendrites) or between a neuron and effector and it is the site of communication

myelin sheath

it covers most long nerve fibers and increases transmission rate of nerve impulses through saltatory conduction

saltatory conduction

the process by which nerve impulses "jump" from one node to the next along a myelinated axon, allowing for rapid and efficient transmission of signals.

nodes of ranvier

gaps between the myelin sheath that is formed by schwann cells

nuclei 

cell bodies in the CNS

Ganglia

cell bodies in the PNS

tracts

nerve fibers in the CNS

Nerves

nerve fibers in the PNS

white matter

collection of myelinated fibers

gray matter

collection of unmyelinated fibers and cell bodies

Sensory Neuron

dendrites associated with specialized receptors, are also cell bodies located outside the CNS

multipolar

has several dendrites plus 1 axom and is the most neurons in the CNS as well as all motor neurons

bipolar

1 axon and 1 dendrite , can be found in the retina of the eye, inner ear, and olfactory area

Unipolar (pseudounipolar)

single process and has fused dendrites and one axon, it is usually a sensory receptor

reflexes

it is rapid, predictable, involuntary responses to stimuli and occurs over reflex arcs

somatic reflexes

it is stimulated by the skeletal muscles

autonomic reflexes

regulates smooth muscles, heart, and glands

two - neuron reflex

simplest type of reflex such as the patellar knee jerk

three - neuron reflex

flexor reflex and consists of the 5 elements of a reflex arc

cerebrum

most superior and largest part of the brain

gyri

elevated ridges of tissue

sulci

shallow grooves

fissures

deep grooves

lobe

named for the cranial bones that lie superficial to them

cerebral cortex

superficial and is composed of gray matter

basal nuclei

islands of gray matter that is deep within the white matter and helps regulate motor activities by modifying instructions

primary somatosensory area

it is posterior to the central sulcus, also called as parietal lobe

primary motor area

it is anterior to the central sulcus, also called as the frontal lobe

visual area

posterior part of the occipital lobe

auditory area

temporal lobe bordering the lateral sulcus

olfactory area

deep temporal lobe

broca’s area

motor speech area and base of precentral gyrus

anterior association area

anterior part of the frontal lobees and is for higher intellectual reasoning

posterior association area

posterior cortex and is for recognition of patterns and faces

cerebral white matter

carries impulses to and from or within the cortex

corpus callosum

connects the cerebral hemispheres

internal capsule

white matter between the thalamus and basal nuclei

diencephalon

also known as interbrain, it is superior to the brainstem but is enclosed by the cerebrum

thalamus

encloses the 3rd ventricle of the brain and is the relay station for the sensory impulses passing upward to the sensory cortex

hypothalamus

it is under the thalamus and regulates the body temperature, water balance, and body metabolism. Also a part of the limbic system and regulates the pituitary gland

mammillary bodies

felex centers involved in olfactionm

epithalamus

forms the roof of the 3rd ventricle

choroid plexus

it forms the csf

brainstem

produced programmed autonomic behaviors and controls vital activities such as breathing and blood pressure

midbrain

extends from the mammillary bodies to the pons inferiorly

cerebral aqueduct

connects 3rd ventricle to the 4th one

cerebral peduncles

two bulging fiber tracts

corpora quadrigemina

four reflex centers in the midbrain responsible for vision and hearing

pons

rounded structure that is protruding below the midbrain and has a nuclei involved in the control of breathing

medulla oblo

meninges

three connective tissue membranecovering and protecting the CNS

dura mater

outermost or tough mother

arachnoid mater

is a thin, web-like layer that, along with the pia mater below it, encloses the subarachnoid space, which is filled with cerebrospinal fluid (CSF) that cushions the brain

pia mater

“gentle mother”, innermost, delicate, clings tightly to the surface of the brain

subarachnoid space

contains the csf

arachnoid granulations

absorbs the csf into the venous blood

cerebrospinal fluid

it is the ultrafiltrate of plasma that is formed by the choroid plexuses and circulates into the subarachnoid space which then return to blood via arachnoid granules

spinal cord

it is the major reflex center and extends from the foramen magnum of the skull to the L1 or L2 vertebra

31 pairs

how many pairs of spinal nerve arise from the cord?

cauda equina

collection of spinal nerves at the inferior end of the vertebral canal

posterior or dorsal horns

where sensory neurons via the dorsal root

ventral or anterior horns

send axons out the ventral root of the cord, where the motor neuron goes out

nerve

bundle of neuron fibers found outside the CNS

endoneurium

surrounds each nerve fiber

perineurium

surrounds group of fibers (forming fascicles)

epineurium

Binds all fascicles together, forms the cordlike nerve

vagus nerve

the only cranial nerve that extend to thoracic and abdominal cavity

sympathetic nervous sytem

fight or flight