Nervous System

sensory input

the use of millions of sensory receptors to monitor changes occuring out and inside the body. These changes stimuli and gather information

integration process

interprets the senosry imput'; makes decisions about should be done at each moment

motor output

a response to from integration by activating muscles or glands

what does the work with to regulate and maintain homeostasis

endocrine system

what does the nervous system control

rapid electrical nerve impulses

what does the endocrine system produce and where are they released

hormones and blood

what does the nervous system consist of

brain and spinal cord

how does the brain and spinal cord act in the nervous system

they act as the integrating and command centers. they interpret incoming sensory information and instructions based on past experiences and current conditions

what does PNS stand for

Peripheral Nervous System

what dos PNS consist of

sensory(afferent) and motor (efferent) and nerves

where does spinal nerves carry impulses

to and from the brain

cranial nerves carry impulses to

to and from the brain

what are the two subdivisions of PNS

sensory and afferent division

where does the two subdivisions that consist of nerve fibers they

convey impulses to the central nervous system from sensory receptors located in various parts of the body

The motor or efferent division carries what to from the CNS

they carry impulses from the CNS to effector organs, the muscles and glands

what are the two subdivisions of motor division

somatic nervous system and autonomic nervous system

somatic nervous systems

allow us to consciously/voluntarily, control our skeletal muscles.

autonomic

regulates events that are __________ or involuntary, such as the smooth and cardiac muscles.

Neuroglia

are supporting cells in the nervous system which generally support insulate, and protect neutrons

two types of neuroglia

neurons and neuroglia

neurons

are ABLE to transmit nerve impulses but they lose the ability to divide

neuroglia type

are NOT able to transmit nerve impulses; they never lose the ability to divide

what does Schwann cells form in the PNS

myelin sheaths around nerve fibers that are found in PIUS

nerve cells

highly specialized to transmit messages from one point of the body to another

what does the cell body contain

usual organelles except for continuous and is the metabolic center of the neuron

dendrites

neuron processes that convey incoming message toward the cell body

axons

processes that generate nerve impulses away from the cell body

how many neurons are in branching dendrites have

hundreds

how many neurons in axon

1 axon

myelin

most long nerve fibers are covered with a whitish, fatty material and has a waxy appearance

what does the myelin do

it protects and insulates nerve fibers and increases the transmission rate of nerve impulses

Schwann cells

axons outside the CNS are myelinated

myelin sheath

schwann cells wrap themselves tightly around the axon jellyroll fushion, a tight coil of the wrapped membrane, the _________ encloses the axon

oligodendrocytes

instead of Schwann cells, neurons in the CNS are myelinated by

scleroses

the myelin sheaths around the nerve fibers are gradually destroyed, converted to hardened sheaths

functional classification groups neurons according to the direction the nerve impulses is

traveling relative to the CNS

Afferent neurons

sensory neurons that are always found in a ganglion outside of the neuron

sensory neurons

keep us informed about what is happening both inside and outside of the body

dendrite ending of the sensory neurons are

usually associated with specialized receptors that are activated by specific changes occurring nearby

motor or efferent neurons

neurons carrying impulses from the CNS to the viscera/ or muscles glands

multipolar neuron

structural classification is based on the number of processes extending form the cell

bipolar neuron

neurons with only two processes, an axon and dendrite

unipolar neuron

single process emerging from the cell body

where are sensory neurons found

ganglia

what are the two functional properties

irritability and conductivity

irritability

which is the ability to respond to a stimulus and convert it into a nerve impulses

conductivity

the ability to transmit the impulses to other neurons, muscles, and glands

reflexes

are rapid, predictable, involuntary responses to stimuli

reflex arcs

reflexes that occur over neural pathways

what does autonomic reflexes regulate

the activity of smooth muscles, the heart, and glands

somatic reflexes include

that stimulate the sketal muscles

meninges

tissue membranes
covering the CN

dura mater

outermost, leathery layer is a double-layered membrane

skull

other layer forms the outermost covering of the brain

arachnoid mater

The middle meningeal layer is the
weblike (cobweb)

pia mater

innermost membrane it also clings tightly
to the surface of the brain and spinal
cord, following every fold

encephalitis

is a serious threat to the
brain because bacterial or viral
meningitis may spread into the
nervous tissue of the CNS

cerebrospinal fluid

“watery broth” similar to blood plasma; has more vitamin C and less protein and ion composition is different

choroid plexuses

which are clusters of capillaries hanging from the roof in each of the brain’s
ventricles

hydrocephalus

if something obstructs its drainage, CSF begins to accumulate and exert
pressure on the brain

how are neurons are kept separated from bloodborne

blood-brain barrier

only substances that get pass by blood-brain barrier

Only water, glucose,and essential amino acids are able to pass through the capillaries of the brain

reflex cord

a two-way conduction pathway to and from the brain

how many pairs are in the spinal nerves

31

quadriplegic

If the spinal cord injury occurs high in the spinal cord,so that all four limbs are affected

how does spastic paralysis happen

If the spinal cord is transected (cut crosswise) or crushed

paraplegic

the legs are paralyzed

how many pairs of cranial nerves

12

where are the cranial nerves

head and neck

neural tubes

extends down the dorsal median plane of the embryo’s body

by what week does the brain formation begin

fourth

brain is often discussed in terms of its four major regions

cerebral hemispheres, diencephalon, brain stem, and cerebellum

the paired cerebral hemispheres enclose which area

brain stem

gyri

entire surface of the cerebral hemispheres exhibits elevated ridges of tissue

sulci

are separated by shallow grooves

fissures

Less numerous are the deeper grooves and separate large regions
of the brain

longitudinal fissure

The cerebral hemispheres are separated by a single, deep fissure

parietal location

Posterior to the
central sulcus

parietal function

Interprets
impulses from
body sensory
receptors

parietal areas

somatic sensory area

occipital location

Rear of brain
above the cerebellum

occipital function

Interprets
impulses from
the eyes

occipital area

visual area

temporal location

Bordering the
lateral sulcus

temporal function

Interprets
impulses from
the ears

temporal area

auditory area

frontal location

Anterior to the
central sulcus

frontal function

Allows us to
consciously
move skeletal
muscles

frontal area

primary motor area

basal nuclei

there are several “islands” of gray matter buried deep within the white matter of the cerebral hemispheres

the basal nuclei help regulate

voluntary motor activities by modifying instructions sent to skeletal
muscles by the primary motor cortex

The 3 major structures of the
diencephalon

thalamus, the hypothalamus, and the epithalamus

thalamus

a relay station for
sensory impulses passing upward to
the sensory cortex

hypothalamus

it plays a role in the
regulation of body temperature,
water balance, and metabolism

hypothalamus regulates

the pituitary gland and
produces 2 hormones of its own

The pituitary gland hangs from

anterior floor of the hypothalamus by
a slender stalk

The brain stem has 3 structures

the midbrain, pons, and medulla
oblongata

pons

is the rounded structure that protrudes just below the midbrain

medulla oblongata contains
centers that control

heart rate, blood
pressure, breathing, swallowing, and
vomiting.

cerebellum provides

the precise timing for skeletal muscle
activity and controls our balance and
equilibrium