NEURO 3000 EXAM 3

Contralateral

on the opposite side of the body

Ipsilateral

on the same side of the body

Cerebrum

CONTRALATERAL

Cerebellum

IPSILATERAL

Brain stem

relay center, connects brain and spinal cord, life functions

Decussation

The crossing of nerve fibers from one side of body to the other

Pyramidal decussation

The point in the lower medulla where corticospinal tract fibers cross to the opposite side

Internal capsule

white matter tract that connects cortex to the thalamus

How do the two hemispheres control motor function?

Left hemisphere controls right side of the body and right hemisphere controls left side

Planes of section

coronal, horizontal, sagittal

Dorsal

top view

ventral

bottom view

two major fissures

longitudinal and transverse

longitudinal fissure

separates left and right hemispheres

transverse fissure

separates cerebrum from cerebellum

boundaries of frontal lobe

bounded by lateral sulcus (ventro-caudally) and central sulcus (dorso-caudally)

boundaries of parietal lobe

bounded by central sulcus (rostrally), lateral suclus (ventrally), and parieto-occipital sulcus (caudally)

boundaries of the occipital lobe

bounded by parieto-occipital sulcus (rostrally) and transverse fissure (ventrally)

boundaries of the temporal lobe

bounded by the lateral sulcus (rostrally and dorsally) and the parieto-occipital sulcus (caudally)

gray matter

neuron cell bodies

white matter

myelinated axons

peripheral nervous system

all nervous tissue outside CNS (brain and spinal cord)

somatic nervous system

controls voluntary movements of skeletal muscles

autonomic nervous system

controls involuntary functions (heart rate, digestion, gland activity)

cranial ganglia

12 CNs, clusters of nerve cell bodies in the PNS that process sensory and motor signals in the head and GI tract

cranial nerves for Taste

VII (geniculate ganglion), IX, X

cranial nerve for auditory

spiral ganglion

cranial nerve for vestibular

scarpa’s ganglion

pseudo-unipolar neurons

single process extending from cell body, bifurcate into peripheral and central branch

ganglion

collection of nerve cell bodies in the peripheral nervous system

Preganglionic neurons of sympathetic nervous system

emanate from thalamus and anterior lumbar regions of spinal cord

Preganglionic neurons od parasympathetic nervous system

emanate from cranial nucleus at anterior end and sacral regions in the posterior region

sympathetic nervous system

fight or flight

parasympathetic nervous system

rest and digest

stages of neurodevelopment

gastrulation, neural tube formation, regionalization/patterning, neurogenesis, axonal pathfinding/synaptogeneisis, target dependent cell death/synaptic pruning

neural induction/gastrulation

day 11-15

neural tube formation

days 16-25

brain vesicle formation

day 28+

neurogenesis & migration

day 36+

3 germ layers (formed during gastrulation)

ectoderm, endoderm, mesoderm

ectoderm

nervous system & skin

endoderm

internal organs

mesoderm

muscle & skeleton

morphogens

neural tissue inducer molecules (NOGGIN)

origin of neural tube

derived from ectoderm and forms CNS

sonic hedgehog gene (Shh)

"ventrilizer" for dorsal-ventral patterning

retinoic acid (RA)

anterior-posterior patterning

major regions of the developing brain

Forebrain (telencephalon, diencephalon), Midbrain (mesencephelon), Hindbrain

Basal telencephalon

Develops into the basal ganglia, including the striatum and amygdala.

Dorsal telencephalon

Develops into the neocortex (cerebral cortex).

Diencephalon

Develops into the thalamus and hypothalamus.

Ventral midbrain (mesencephalon)

Develops into the substantia nigra and ventral tegmental area (VTA).

Dorsal midbrain (mesencephalon)

Develops into the auditory and visual tecta (superior and inferior colliculi).

Thalamus

It is the gateway to the cerebral cortex, relaying sensory information.

corpus callosum

white matter tract connecting cerebral hemispheres

corticospinal tract

connections between brain and spine, direct control of movement

basal ganglia

structures in the forebrain that help to control movement (substantia niagra in midbrain)

corpus callosum

white matter tract connecting cerebral hemispheres, carries information btwn hemispheres

dorsal part of midbrain

becomes tectum (superior colliculus) - for visual processing, and inferior colliculus - auditory processing

ventral part of midbrain

becomes tegmentum (VTA, SNr, etc.)

central aqueduct

connects the third and fourth ventricles

dorsal part of rostral hindbrain

becomes cerebellum

ventral part of rostral hindbrain

becomes pons

medullary pyramids

carry corticospinal projections heading toward spinal cord

3 stages of neurogenesis

proliferation, migration, and differentiation

two layers of brain vesicles

ventricular zone and marginal zone

symmetric cell division

expands number of radial glia progenitor cells

main progenitor cell in neurogenesis

radial glia

asymmetric cell division

generates post-mitotic cells that migrate and differentiate into neurons and glia

Cortical layer development

Inside-out development: New neurons migrate past older ones to form the outer layers of the cortex.

order of cell type generation in neurogenesis

pyramidal neurons, astrocytes, inhibitory neurons & oligodendrocytes

Final stages of neural development

Differentiation, dendrite and axon guidance, synaptogenesis, target-dependent cell death, synaptic pruning

four lobes of the brain

frontal, temporal, parietal, occipital

Semaphorin 3A

guidance cue secreted by cells repels the axon and attracts the dendrite (high in MZ)

pyramidal neurons

large excitatory projection neurons (long neurons project to spinal cord)

Chemoattraction and chemorepulsion

axon growth and guidance to target

synaptogenesis

formation of synapse

target dependent cell death

more neurons are generated than are actually needed

synaptic pruning

the elimination of neurons as the result of nonuse or lack of stimulation

synaptic plasticity

the ability of a synapse to change over time through use or disuse

frontal lobe function

complex human behavior (action and executive function)

prefrontal cortex

planning, orgnaizing, impulse control, learning, decision making

primary motor cortex

voluntary movement (caudal part of frontal lobe)

somatosensory cortex

rostral part of parietal lobe

Broca's area

controls motor function involved with language (frontal lobe)

Wernicke's area

controls language comprehension (temporal lobe)

temporal lobe function

language, hearing, and memory

ventral stream

visual what pathway, object visual recognition (temporal lobe)

parietal lobe function

somatic sensory processing

primary somatosensory cortex

in parietal lobe, skin senses (touch, warmth, cold and pain)

dorsal stream

visual where pathway, motion, visual-motor control

occipital lobe function

processes visual information

left hemisphere specialization

language processing and logical/analytical thought

right hemisphere specialization

spatial relationships, abstract thought, creativity

diencephalon structures

thalamus and hypothalamus

thalamus

recieved sensory info from all sensory systems and relays to respective cortical projection areas

hypothalamus

plays major roles in controlling emotion and motivated behaviors

optic tectum

superior colliculus, vision

auditory tectum

inferior colliculus, audition

tegmentum

SNr (movement), VTA (motivation)