AP exam 3

brain, ear, eye, cns, ans

specialized areas of the cerebral cortex

- Broca's area

- Wernicke's area

Wernicke's area

- portions of parietal, temporal lobes

- meanings of speech

Broca's area

- in frontal lobe

- near lateral sulcus

- speech center

Internal cerebrum

- white matter

- basal ganglia

- major basal nuclei

white matter

- inferior to cerebral cortex

- axons to/from the cortex

basal ganglia

- inferior to portions of cerebrum

- areas of gray matter

- refinement of movements

- starting and stopping movements

- connections to cerebral cortex

- connections to midbrain (defect in parkinson's disease)

major basal nuclei

- caudate

- putamen

- globus pallidus

limbic system

- regions responsible for emotions

- located throughout brain

- prefrontal cortex= executive functions

- hypothalamus

- nucleus acumbens

- hippocampus, cingulate gyrus

- amygdaliod nuclei

hypothalamus

- relates emotions to endocrine system

nucleus accumbens

- reward system

hippocampus, cingulate gyrus

- memory

- concept of "self"

amydaliod nuclei (amygdala)

- fear

dicephalon

- below cerebrum

- contains 2 areas

- 1. thalamus

- 2. hypothalamus

thalamus

- under cerebrum

- neural connections to/from cerebrum

hypothalamus

- below thalamus

- connections to pituitary gland + endocrine system

- limbic system

- hunger/thirst

- fever

fever

- responds to pyrogens

- increases immune function

Brainstem

- 1. midbrain

- 2. pons

- 3. medulla

midbrain

- superior portion of brainstem

- contains substantia nigra

-contains corpora quadrigemina

substantia nigra

- area of dark tissue

- dopamine production

- axons to cerebrum

- degeneration leads to parkinson's disease

corpora quadrigemina

- 4 lobes in posterior midbrain

- superior (2 lobes) for visual reflexes

- inferior (2 lobes) for auditory reflexes

pons

- middle portion of brainstem

- forms ventral bulge

- forceful breathing

- contains reticular formation

- name means bridge ( to cerebellum)

- cerebellar peduncles

reticular formation

- throughout brainstem

- wakefulness, sleeping, dreaming

medulla

- inferior portion

- autonomic functions

- calm breathing

- swallowing, vomiting

- heart rates

- ascending tracts from spinal cord to brain

- descending tracts from brain to spinal cord

- descending conscious motor nerves known as pyramidal tracts

- decussation of the pyramids

- medulla continous inferiorly with spinal cord

decussation of the pyramids

- crossing of pyramidal tracts as they descend

cerebellum

- posterior to brainstem

- superficial gray matter= cerebellar cortex

- internal white matter= arbor vitae

- cerebellar peduncles= connections to brainstem

- functions in coordination/ learned movements

- half of all neurons in the brain

ventricles

- internal cavities in brain

- lateral ventricles

- interventricular formina

lateral ventricles

- horn shaped

- contain choroid plexus= tissue that produces csf

interventricular formina

- conduct csf from lateral ventricles to third ventricle

3rd ventricle

- near thalamus

- contains choroid plexus

cerebral aquaduct

- conducts csf from 3rd ventricle to 4th ventricle

4th ventricle

- posterior brainstem

- contains choriod plexus

pathways for CSF from 4th ventricle

- central canal to spinal cord

- medial and lateral apertures to subarachnoid space

modifications in dura mater

- falx cerebi

- tentorum cerebelli

- dural venous sinuses

falx cerebi

- down longitudinal fissure

- separates cerebral hemispheres

tentorum cerebelli

- separates cerebrum from cerebellum

dural venous sinuses

- large veins in dura

- connected to subarachnoid space via arachnoid villi

- CSF to blood via villi

pineal gland

- posterior to midline of 3rd ventricle

- production of melatonin= improves sleep, and produced during darkness

glioma

- glial cell tumor= most common brain tumor (several types)

- symptoms are headache, movement problems, personality changes, speech difficulties

- diagnosis is mri and biopsy

- treatment is surgery, radiation therapy, chemotherapy, immunotherapy

ALS

- amyotrophic lateral sclerosis

- lou gehrig's disease

- death of motor neurons

- upper motor neurons (cns)

- lower motor neurons (pns)

- symptoms are weakness, muscle atrophy (lower), spasms (upper)

- onset is any age possible but about 60 yrs old most common

ALS cause + diagnosis

- cause is unknown in 90-95% cases

- genetic in 5-10% cases increases chance by 1%

- diagnosis is symptoms and elimination of other causes

- no cure and average life expectancy is 2-4 yrs

cranial nerves

- 12 nerves that exit directly out of brain

CNI Olfactory nerve

- smell

- from olfactory epithelium in roof of nasal cavities

- to cerebrum

CNII Optic nerve

- vision

- from retina to thalamus

CNIII Oculomotor nerve

- to most muscles of eye movement

CNIV Trochlear nerve

- to superior oblique muscle

- turns eye down and to side

CNV Trigeminal nerve

- motor branch to muscles of mastication

- 3 sensory divisions

- 1. ophthalmic to forehead

- 2. maxilliary to cheeks

- 3. mandibular to lower jaw

CNVI Abducens nerve

- to lateral rectus muscle

- turns eye laterally

CNVII Facial nerve

- to muscles of facial expression

- sensory from taste buds of anterior tongue

- motor to salivary glands

- paralysis leads to Bell's palsy

CNVIII Vestibulocochlear nerve

- cochlear branch from inner ear for hearing

- vestibular branch from inner ear for positions and movement of the head

CNIX Glossopharyngeal Nerve

- motor to pharynx

- sensory from taste buds of posterior tongue

- sensory from pharynx (gag reflex)

CNX Vagus nerve

- parasympathetic division of autonomic nervous system

- organs of chest, abdomen

CNXI Accessory nerve

- cranial and spinal in origin

- motor to trapezius and sternocleidomastoid

CNXII Hypoglossal nerve

- motor to muscles of tongue

brain

- cerebrum

- cerebral cortex

- frontal lobe

- parietal lobe

- parieto- occipital sulcus

- occiptial lobe

- temporal lobe

- insula

cerebrum

- supeior portion

- largest portion in humans

- 2 hemispheres (left, right)

- longitundinal fissure separates hemispheres

- corpus callosum

Left hemisphere

- language, quantitative

right hemisphere

- spatial

corpus callosum

- connects hemispheres

cerebral cortex

- surface of cerebrum

- gray mater

- gyri

- sulci

gyri

- ridges designed to increase surface area

sulci

- grooves between gyri

lobes

- divisions of cerebrum

- frontal

- parietal

- occipital

- temporal

frontal lobe

- separated from posterior areas by central sulcus

- 3 regions

- 1. precentral gyrus

- 2. motor association area

- 3. prefrontal cortex

precentral gyrus

- primary motor cortex

- control of conscious movement

- distributions of body controls shown by homunculus

motor association area

- anterior to precentral gyrus

- understanding of movements

prefrontal cortex

- anterior portion of frontal lobe

- complex through processes

- emotions

parietal lobe

- posterior to central sulcus

- 3 regions

- 1. post central gyrus

- 2. sensory association

- 3. primary olfactory cortex

post central gyrus

- conscious perception of body sensation

sensory association

- understanding sensation

- integrates various sensations

primary olfactory cortex

- smell

parieto-occipital sulcus

- posterior to parietal lobe

- separates parietal lobe from occipital lobe

occipital lobe

- posterior portion of cerebral cortex

- 2 regions

- 1. primary visual cortex

- 2. visual association

primary visual cortex

- posterior

- conscious visual perception

visual association

- anterior portion of lobe

- understanding visual image

- integration with other areas

temporal lobe

- lateral cortex

- separated from remainder of cortex by lateral sulcus

- 2 regions

- 1. primary auditory cortex

- 2. auditory association

primary auditory cortex

- conscious perception of hearing

auditory association

- understanding of sounds, integration with other areas

insula

- small lobe deep in lateral sulcus

- memory

- primary gustatory center responsible for taste

autonomic nervous system

- unconscious

3 step motor nerve pathway

3 step motor nerve pathway

1. preganglion fibers (nerves)

2. ganglion

3. postganglionic fibers

preganglion fibers (nerves)

- cns to ganglion

ganglion

- nerve cell bundle outside cns

postganglionic fibers

- from ganglion to effector organ

sympathetic nervous system

- division of autonomic nervous system

- fight or flight activities

- preganglionic fibers from thoracic and lumbar spinal nerves

- ganglia along spinal cord, in abdomen, in chest

Sympatheitc nervous system postganglion fibers

the postganglionic fibers are responsible for

- increase heart rate

- increase respiration

- increase blood to muscles

- decrease digestive function

- dilate pupils

- increase blood glucose

parasympathetic nervous system

- division of autonomic nervous system

- rest and repose activities

- preganglionic fibers from cranial and sacral nerves

- ganglia near effector organ

parasympathetic nervous system postganglionic fibers

postganglionic fibers responsible for

- decrease heart rate

- decrease respiration

- decrease blood to muscles

- increase digestive functions

- constrict pupils

- decrease blood glucose

cranial nerve involvement in para ns

- cranial 3= focuses eyes

- CN Vll= tears, salivary glands

- CN IV= salivary gland

- CN X= abdominal, thoracic organs

Autonomic Transmitters

in the sympathetic division...

- acetlycholine

- norepinphrine

Acetylcholine

- released from preganglionic nerves

- stimulate postganglionic nerves

- major neurotransmitter

- from pregang to postgang nerve fibers

norepinephrine

- released from postganglionic nerves

- stimulates effector organs

norepinephrine receptors

adrenergic receptors

- alpha= vasoconstriction

- beta= increase heart rate

Acetlycholine receptors

cholinergic receptors

- nicotinic= nerve stimulators

- muscarinic= increase GI activity, decrease heart rate

eye

contains

- lacrimal gland

- tear pathway

- conjuctiva

lacrimal gland

- anterior and lateral to eye

- produces tears

tear pathway

- medial across eye

- to lacrimal puncta

- to lacrimal canaliculi

- to lacrimal sac

- to nasolacrimal duct

- to nasal cavities

conjuctiva

- clear mucous membrane

- two parts

- 1. bulbar conjuctiva

- 2. palpebral conjuctiva

bulbar conjuctiva

- on anterior surface of eye

- absent over cornea

palpebral conjunctiva

- under eyelid

eyeball structure

- 3 layers

- 1. scerla

- 2. vascular tunic (choroid)

- 3. retina