HAN 312 Lecture 6

Central Nervous System (CNS)

-brain

-spinal cord

Peripheral Nervous System (PNS)

Nerves throughout the body
• Cranial nerves
• Spinal nerves
• Autonomic Nerves/ Nervous System: involuntary bodily functions
• Sympathetic Nervous System: influence bodily functions during times of stress
• Parasympathetic Nervous System:
heart rate, breathing, GI tract muscles

Brain

• Cerebrum

• Diencephalon

• Cerebellum

• Brainstem

Cerebrum

largest and uppermost portion of the brain; divided into
right and left halves (called cerebral hemispheres) and subdivided into lobes

Cerebral Cortex

surface nerve cells; gray matter; controls higher
mental functions (speech, vision, smell, movement, hearing, &
thought)

Gyrus

raised convolution on the surface of the cerebrum

Sulcus

groove or fissure on the surface of the brain

Frontol lobe

front portion of the cerebrum that controls voluntary muscle
movement and is involved in emotions

Occipital Lobe

back portion of the cerebrum that controls vision

Parietal Lobe

middle-top portion of the cerebrum involved in perception of
touch, temperature, and pain

Temporal Lobe

Portion of the cerebrum below the frontal lobe; controls senses of hearing a smell as well as memory, emotion, speech, and behavior

Diencephalon

Hypophysis: Area deep within the brain that
contains the thalamus, hypothalamus, and pituitary
gland; Responsible for directing sensory information to the corte

Thalamus

Integrates and monitors impulses from the skin, ie pain

hypothalamus

beneath the thalamus, controls body temperature, sleep, appetite, sexual desire, and hormones (released from pituitary gland)

Cerebellum

Hindbrain; posterior portion of the brain, coordinates the voluntary muscles and maintains balance

Brainstem

connects the brain to the spinal cord; assists in
breathing, heart rhythm, vision, and consciousness

midbrain

Mesencephalon: uppermost part of the brainstem that
connects the brainstem to the cerebellum; controls sensory processes

Pons

bridges cerebrum & cerebellum with the rest of the brain;
houses nerves for the face & eye

Medulla Oblongata

part of the brainstem that connects the brain and the spinal cord; controls respiration, heartbeat, and blood vessel size

Ventricle

one of four interconnected cavities within the
brain that contain & secrete cerebrospinal fluid

Cerebrospinal Fluid (CSF)

colorless fluid that circulates in and around the brain and spinal cord; acts as a protector and transports nutrients

Meninges

membranous covering of the brain and spinal cord

Dura Mater

strong fibrous outermost layer of the meninges
• Subdural space

arachnoid

delicate fibrous membrane forming the middle layer of the meninges
• Subarachnoid space

Pia Mater

thin inner layer of the meninges that attaches directly to the
brain and spinal cor

Spinal Cords

Portion of the central nervous system contained in the spinal or vertebral canal
• Responsible for nerve conduction to and from the brain
and body
• Begins at the brainstem and ends at the first & second
lumbar vertebrae, culminating in the cauda equina

Neurons/ Nerve Cells

Individual nerve cells that make up the basic structure of the nervous system and conduct impulses; ~10 billion in the adult
• Collect into macroscopic nerves
• Anatomical portions of a neuron:
•. Dendrite
•. Cell body
• Cell nucleus
• Axon
• Myelin sheath
• Terminal end fibers (secrete
neurotransmitters across synapse)

Ganglion

group of nerve cell bodies located along the pathway of a nerve

Plexus

interlacing network of nerves

neurotransmitters

chemical messenger released into a synapses by a neuron, either stimulates or inhibits another cell

nerves

cordlike structure that transmits stimuli

afferent/sensory nerves

carry messages toward the brain

efferent/ motor nerves

carry messages away from the brain

mixed nerves

carry both sensory and motor fibers

dorsal root

carries sensory impulses toward the spinal cord/ brain

ventral root

carries motor impulses away from the brain'/ spinal cord to muscles or glands

cranial nerves

12 pairs of nerves that emerge from the cranium
• Ex: vagus nerve (CN X) which branches reach to larynx, trachea, bronchi, lungs, aorta, esophagus, & stomach

Spinal Nerves

31 pairs of nerves that emerge from the spine
• Ex: sciatic nerve extending from base of spine down the thigh, lower leg, & foot

Neuroglia/ glia

cell that support and protect nervous tissue. do not transmit impulses

astrocytes

provide structural and metabolic support, repair cells

oligodendrocytes

myelinate axons and insulte electrical impulses

ependymal cells

produce and moves CSF

microglia

defense and immune response

stallite cells

provide structural and metabolic support for cell body of neurons

Schwann cells

myelinate axons and insulate electrical impulses

Cerebral Palsy

defect of motor power and coordination related to damage to the brain that occurred prenatally, perinatally, or in the first 3 years of li

Hydrocephalus

Condition involving increased CSF; leads to enlargement of cerebral ventricles and increase in
intracranial pressure (ICP); may cause cranial enlargement

Seizure

spasms or series of jerky movements of the face, trunk, or limbs

Epilepsy

Disorder involving seizure activity and alterations of consciousness

Postictal

pertaining to following a seizure

Alzheimer disease

a degenerative progressive brain disease that results in impairment of language function, inability to calculate, and deterioration of judgment

coma

state of profound unconsciousness

Amyotrophic Lateral Sclerosis (ALS)/ Lou Gehrig Disease

condition marked by a progressive deterioration of motor nerve cells; leads to muscle weakness and eventually paralysis and death

Huntington’s Disease/ Huntington Chorea

genetic, progressive deterioration of nerve cells; usual presentation around 30-40 years old

multiple sclerosis (MS)

common disorder of the central nervous system that causes sclerotic patches (plaques) in the brain and spinal co

myasthenia gravis (MG)

autoimmune disorder characterized by rapid fatigue of voluntary muscles

Parkinsonism, Parkinsons Disease PD

defective disorder of the CNS that often impairs the sufferers motor skills and speech; most notably characterized by tremors of limbs

bell Palsy

paralysis of facial muscle, often on one side of the face, caused by a dysfunction of cranial nerves; can have infections etiology

Tourette syndrome

characterized by intermittent motor and vocal manifestations referred to as “tics” that often begins in childhood

Herpes Zoster/ Shingels

painful viral infection (varicella) affecting peripheral nerves; causes eruption of blisters that follows the course of the affected nerves

meningitis

inflammation of the meninges can be bacterial, viral

poliomyelitis

inflammation of the gray matter of the spinal cord which can
lead to temporary or permanent paralysis

HIV encephalopathy

dementia caused by HIV

Concussion

injury to the brain resulting from a blow or violent shaking; usually no evidence of structural damage to brain tissue

Cerebral contusion

bruising of brain tissue secondary to trauma to the head;
may be associated with skull fracture, edema, increased intracranial pressure

epidural hematoma

a collection of blood above the dura mater resulting from a
broken blood vessel, usually due to trauma

Subdural hematoma

a collection of blood below the dura mater resulting from
a broken blood vessel, usually due to trauma

subarachnoid hemorrhage

a collection of blood within the subarachnoid space
resulting from a broken blood vessel, usually due to trauma

cerebrovascular accident (CVA)/ Stroke

damage to the brain caused by an
interruption of blood supply to a region of the brain
• Embolic: obstruction or occlusion of a vessel in the brain by an embolus
• Thrombotic: clot within a blood vessel of the brain
• Hemorrhagic: blood vessel breaks causing bleeding

Cerebral Aneurysm

Widening of a blood vessel in the brain, usually due to a weakness in the wall of the artery

transient Ischemic attack (TIA)

sudden, brief, and temporary cerebral dysfunction usually caused by interruption of blood flow to the brain
• Ischemic: pertaining to lack of blood flow

Migraine

recurrent syndrome characterized by unilateral head pain, vertigo,
nausea, and sensitivity to light

Narcolepsy

recurring episodes of REM sleep during the day and often
disrupted nocturnal sleep

radiculopathy

disease of the nerve roots

babinski signs

toe movement elicited by manipulation in a neurologic test performed on the sole of the foot to indicate injury to the brain or spinal nerves

deep tendon reflex

evaluation of the response of a muscle to stimuli to provide information on the integrity of the central and peripheral nervous
system

Glasgow Coma scale

a neurologic scale used to assess level on consiousness

CT of the head

usually w/o contrast to assess for any gross abnormalities,
including trauma/ hemorrhages/ ischemia

Magnetic resonance imaging

imaging technique that uses magnetic fields and radiofrequency waves to visualize anatomic structures

Cerebral Agiography

radiography of blood vessels in the brain after injection of
radiopaque contrast material (ie CTA, MRA)

Positron Emission Tomography

a nuclear medicine procedure that shows blood flow in the brain that can correspond to various brain activity

Myelogram

radiographic contrast study of the spinal subarachnoid space and its contents

Electroencephalogram

electrical recording of activityy of the brain

evoked potential studies

diagnostic test that use a EEG to record change in brain waves during various stimuli

lumbar puncture

the process of inserting a needle into the subarachnoid space of the lumbar spine to obtain cerebrospinal fluid for analysis

neurolysis

separation of a nerve from inflammatory adhesions

electroencephalography technician

a person who is trained to set up and perform electroencephalograms

eyelids

provide protection; mucous membrane lining called the conjunctiva lines the eyelids of the outer surface of the eyeball

sclera

tough outer layer of the eye (whites of the eye) extending from cornea to optic nerve

cornea

transparent outer covering of anterior portion of eye

aqueous humor

watery fluid within anterior chamber of eye

iris

colored mucular portion behind cornea; allows light to pass through

pupil

opening in the middle of the iris allowing light to pass

lens

transparent biconvex structure behind pupil which bends and focuses light rays

choroid

middle layer of the eye that contains blood vessels

vitreous humor

jellylike fluid that fills the posterior chamber of the eye behind the lens (vitreous chamber)

retina

innermost layer of the eyes that contains visual receptors

optic nerve

nerve that carries impulses from retina to brain provides sense of sight

fundus

posterior portion of interior of eyeball; area of examination vis ophthalmoscope

lacrimal glands

provide lubrication fluid (tears)