Study Guide on Canvas

CNS

composed of brain and spinal cord

PNS

composed of cranial nerves and spinal nerves

Gray Matter

composed of unmyelinated interneurons, dendrites and cell bodies

L: cortex (superficial layer), nucleus (cluster of neuron cell bodies)

F: integrating and processing area

White matter

myelinated axons

L: tracts, peduncles, funiculi

F: relay nerve signals

Cerebellum

L: inferior to cerebrum

F: coordinates/fine tunes skeletal muscles movements, ensures skm follow correct pattern = smooth, muscle memory

Brainstem

three regions: midbrain, pons, medulla oblongata,

Diencephalon

epithalamus, thalamus, hypothalamus

Cerebral Cortex

outer layer of brain, composed of gray matter

Thalamus

(part of dicephalon)

L: form walls superolateral of third ventricle between anterior commissure and pineal gland

F: relay center of sensory input to appropriate regions of cerebrum

Hypothalamus

(part of diencephalon)

L: anteroinferior region of diencephalon

F: ANS, regulates endocrine system, temp regulation, water balance, hunger/thirst, sleep/wake cycles

Medulla Oblongata

L: inferior part of brainstem continuous with spinal cord inferiorly

F: reflex center for vomiting, hiccupping, sneezing, coughing, regulation of heart rate, breathing rate, blood pressure

Layers of the meninges

from outer to inner

• dura mater, arachnoid matter (subarachnoid space contains CSF), pia mater

Premotor Cortex

skilled, repetitive motor output comes from there (muscle memory)

Projection fiber

carry out motor output from and sensory input to the brain to opposite side of body

Association fibers

connects areas of brain within same hemisphere

Corpus callosum

L: tracts of white matter between cerebral hemispheres

S: coordinate movement/communication between sides

Parts of reflex arc

receptor, sensory neuron, integration center (spinal cord and interneuron), motor neruon, effector

Mechanoreceptors

receptors for vibration, pressure, sound, touch, strech

Photoreceptors

receptors for wavelengths of light

Nociceptors

receptors for pain

Chemoreceptors

detect chemical signals for taste, smell, blood and CNS chemistry

Proprioceptors

• receptors for balance from muscles

• receptors associated with muscle spindles

Thermoreceptors

receptors for hot and cold

Pons

L: buldging region anterior part of brainstem

F: coordinates motor output with cerebellum and influences breathing rate

Reticular Formation

L: loosely organized gray matter projecting vertically through midbrain, pons, medulla oblongata

F: sensory input from body sent to thalamus from here, muscle tone, loss consciousness or coma results from damage here

Frontal lobe

L: deep to frontal bone forms anterior cerebral hemisphere

S: personality: all judgement, decision making, planning, etc originates here

Parietal Lobe

L: deep to parietal bone forms superoposterior part of cerebral hemispheres

F: sensory input from skin and sensory input regarding body position from proprioceptors

Temporal lobe

L: internal to temporal bone

F: hearing and smell

Occipital lobe

L: internal to occipital bone

F: visual input from optic nerve comes here

Insula

L: deep to lateral sulcus

F: sensory input for taste

Gyri

ridges in brain that increase surface area for interneurons

Sulci

grooves in cerebrum to increase surface area, surrounded by gray matter

Primary sensory areas in the brain

conscious awareness of senation

Association areas in the brain

necessary for understanding, integrating sensory input

Precentral gyrus

L: anterior to central sulcus

F: all voluntary motor output

Postcentral gyrus

L: posterior to central sulcus

F: all somatosensory input (touch, temp, pressure, pain)

Broca’s area

L: inferolateral portion of left frontal lobe
F: speech production comes from there

Wernicke’s area

L: within left hemisphere overlapping parietal and temporal lobes
F: understanding speech in temporal lobe

Left hemisphere

receives sensory input from and sends motor output to right side of body

Right hemisphere

receives sensory input from and sends motor output to left side of body

Cerebellum

hand eye coordination motor output regulation

Spinal cord

consists of gray matter on the inside and white matter on the outside with 31 pairs of mixed nerves

Withdrawal/flexor reflex

also known as flexor reflex, occurs when damaging stimuli are received (touching something hot)

Crossed extensor reflex

reflex that occurs when stimulus and withdrawal reflex occur on one side while extensor reflex occurs on other (don’t fall down)

Muscle spindles

receptors wrapped around muscle fibers that allow muscle tone to occur

Golgi tendo reflex

stretch receptors in tendons that precent over contraction in muscle

Blood brain barrier

prevents harmful materials from entering CSF, astrocytes make this

Choroid plexus

makes CSF

Ventral root of spinal nerve

if cut in spinal nerve, no muscle contraction would occur but sensations would still be felt

Doral root of spinal nerve

if cut in spinal nerve, no sensatin would be felt but muscle contraction could still occur

Dermatomes

areas of skin innervated by sensory branches of each spinal nerves, where shingles appear on body

Basal ganglia

Huntington’s disease

disease caused by dysfunction of basal nuclei

Parkinson’s disease

disease caused by dysfunction of basal nuclei

Adaptation

lack of perception of sensory input even though stimuli are still present

Neural tube formation

begins a neural groove and folds from embryonic ectoderm

Babinski’s sign

toes fanning and dorsiflexing when sole of foot is stroked due to cerebral cortex damage

Limbic system

emotional area of brain, especially during fight or flight, fear, anger