Neuro Exam 1

what is interconnectivity?

every part of the nervous system is interconnected through fibers because of this messages from one area of the brain can trigger responses from many other regions of the brain

what is association regarding interconnectivity?

same hemisphere

what is commissural regarding interconnectivity?

across hemisphere

what is projection regarding interconnectivity?

goes down or up

What is centrality?

everything is connected through the CNS, all activity goes to and from the CNS

What is bilateral anatomic symmetry?

hemispheres are near mirror images

what is unilateral function asymmetry

each hemisphere has different functions

what is contralateral sensorimotor control

motor and sensory functions are controlled by opposite side of the brain

what are functional networks

sensory and motor systems have specialized cells that carry out each systems function. each pathways carry specific types of messages

topographical organization

cells are arranged in the brain according to body’s spatial organization

homunculus

neurological map of the areas and portions of the brain dedicated to processing motor functions or sensory functions for different parts of the body

plasticity

the brain changes with experience ex. learning

what is brain function unaffected by

sex, race, brain size shape or weight

central nervous system is made of

brain, spinal cord and inside skull and vertebrae

peripheral nervous system is made of

nerves and ganglia (cell bodies) outside of the brain and spinal cord, connects CNS to muscles glands and organs, outside the skull and vertebra

what is covered in a thick layer of gray matter (cell bodies)

cerebral cortex

what is cerebral cortex responsible for?

higher level mental and sensorimotor functions

dorsal (brain)

(superior) top of brain

ventral (brain)

(inferior) bottom of the brain

lateral (brain)

structures away from the midline

medial (brain)

structures closer to the midline

rostral (brain)

(anterior) toward the nose, near front of head

caudal (brain)

(posterior) toward the back of the brain

dorsal (brainstem)

toward the back

ventral (brainstem)

toward the front or abdomen

rostral (brainstem)

toward the brain

caudal (brainstem)

toward the end of the spinal cord

coronal plane

cuts into front and back

sagittal plane

cut into right and left sides

midsagittal plane

cut into equal left and right halves

horizontal plane

cuts into top and bottom (aka axial and transverse)

structural brain scans

tell us what the brain looks like

functional brain scans

tell us which part of the brain is active in response to a stimulus

what does CT scan do?

use narrow beam of xrays to examine the brain slices in series, creates 2d image based on absorbed xray particles.

CT angiography (CTA)

cintrast is injected into the bloodstream to visualize the vascular system

Magnetic resonance imaging (MRI)

measurement of tissue responses to applied magnetic field to radiofrequency (RF) waves

functional MRI

measures the effects of blood oxygen level dependent, a part of brain is involved in a task or activated by a stimulus exhibits greater neuronal activity

positron emission tomopgraphy (PET)

detects signals from a radioactive substance (called a tracer) look for disease or injury in the brain

electroencephalography (EEG)

measures brain electrical activity

wada test (sodium amytal infusion)

involves injections of sodium amobarbital during cerebral angiography to determine cerebral dominance of specific functions (specifically language)

what do neurons do?

process info, over 100 billion neurons in the brain

what do glia cells do?

insulate, support and nourish neurons “glue”, about 10x more glial cells than neurons

soma

cell body

neurite

thin tube extending from a neuronal cell body

dendrites

receive info from other neurons and carry info to the soma

axon

single long fiber that conducts nerve impulses away from cell body to other parts of the nervous system, glands or muscles

axon hillock

beginning

axon proper

middle

axon terminal

end

myelin sheath

fatty insulation

neurotransmitters

chemical substance that causes transfer of info into neighboring cells

acetylcholine

muscle contraction, heart rate

norepinephrine

arousal, learning, mood

serotonin

regulate sleep, mood, eating

dopamine

regulate movement and pleasure. related to parkinsons

GABA

inhibits firing of neurons

glutamate

excitatory and strengthens neuronal connections, excite other cells

action potential

basic events the nerve cells use to transmit info from one place to another

what affects speed transmission of action potential

• diameter of axon (larger —> faster)

• myelination of the axon (more myelin, faster transmission)

• length of axon (shorter axon, faster transmission)

neurons are

not randomly scattered throughout the body, arranged in discrete locations

ganglion

group of neurons outside the CNS

nucleus

group of neurons within the CNS (grey matter)

nerve

group of nerve fibers (axons) outside the CNS (in PNS)

tract

group of nerve fibers (axons) within the CNS

what is white matter?

myelin sheath

motor (efferent) neurons

carry motor info from CNS to PNS and cause muscles to contract

sensory (afferent) neurons

carry sensory info from PNS into the CNS

interneurons

lie within the CNS and process info carried by both motor and sensory neurons

neuroglia

neuron support

astrocytes

• transport nutrients to neurons

• clean up cell debris and involved in scarring after brain damage

• facilitate neurotransmitter reuptake via endocytosis

microglia

digest parts of dead neurons

ependymal cells

• line fluid filled spaces of brain and spinal cord

• production of cerebraspinal fluid

• role in guiding cell migration during brain development

oligodendrocytes

provide the insulation to neurons in the central nervous system

schwann cells

provide the insulation to neurons in the peripheral nervous system

satellite cells

physical support to neurons in the peripheral nervous system

which nerve cells recover faster PNS or CNS

PNS

brain tumors can cause

aphasia, dysarthria, dysphagia, cognitive impairments

aphasia

language impairment

dysarthria

motor speech impairment

dysphagia

swallowing problems

cognitive impairments

attention, memory, executive functioning

3 meninges

dura mater, arachnoid mater, pia mater

latin meaning for dura mater

tough mother

latin meaning for arachnoid mater

spider mother

latin meaning for pia mater

pious mother

dura mater

dense, fibrous, outermost layer

2 layers in dura mater

periosteal and menigeal

falx cerebri

in interhemispheric/longitudinal fissure, forms vertical partition between cerebral hemispheres

tentorium cerebelli

between the basal surfaces of temporal and occipital lobes and he cerebellum

falx cerebelli

between cerebellar hemispheres

arachnoid mater

thin membrane between dura and pia layers

pia mater

• thin, adheres to surfaces of brain follows the contours

• highly vascular: carries arteries and veins to neural tissue

order of meninges

PAD: pia mater (inner), arachnoid mater (middle), dura mater (outer)

cerebospinal fluid

in ventricles, for protection. brain floats in CSF

major divisons of the brain

cerebrum, cerebellum, brain stem

neuralation

neural plate and neural tube development (weeks 3 and 4 of gestation)

latin term for brain

encephalon

spina bifida

a birth defect that occurs when the spinal cord and surrounding membranes don’t close completely during pregnancy

anencephaly

a serious birth defect in which a baby is born without parts of the brain and skull

describe divisions of the brain