Neruo lab 3

Pyramidal cells

axons travel through white matter as projection, commisural, or association fibers

most pyramidal calls are output cells from the

cerebral cortex

Fusiform cells

spindle shaped output cells of cerebral cortex

fusiform cells project mainly to the

thalamus

stellate/granule cells

small neurons remain within the cortex and serve as interneurons

projection fibers

extend from subcortical structures to the cerebral cortex and from the cerebral cortex to the thalamus, basal nuclei, brainstem and spinal cord.

commissural fibers

connect homologous areas of the cerebral hemispheres and connect the right and left hemisphere

largest group of commissural fibers. thick band of fibers connecting the 2 hemispheres

corpus callosum

Callosotomy

surgical procedures to cut through the corpus callosum and disconnect the cerebral hemispheres.

“split brain”

usually served in order to stop severe epileptic seizures that cannot be controlled through other means

Association fibers

connect cortical regions within ONE hemisphere

short association fibers connect

adjacent gyri

long association fibers connect

lobes with one hemisphere

Basal nuclei aka basal ganglia

cluster of neuron cell bodies that run along with the cerebellum

the basal ganglia

fine tune and provide control for voluntary movements

Basal nuclei regulate

sequencing of movements, muscle tone, muscle force and intensity (also help regulate complex movements executed by the cerebral cortex)

output from the basal nuclei, particularly the globus pallidus and substantia nigra, influence

muscle movements

Basal nuclei include the following five clusters of nuclei (gray matter)

caudate nucleus, putamen, globus pallidus, subthalamic nucleus, substantia nigra

the basal nuclei are seperated by the

internal capsule

The internal capsule is an area of white matter that runs between

the thalamus and basal nuclei

disorders of the basal nuclei cause

decreased or increased body movements. (hypokinetic and hyperkinetic disorder

hypokinetic disorders

decrease in the amount and speed of voluntary and autonomic movements.

example: parkinsons

parkinsons is caused by

degeneration of dopamine producing neurons of the substantia nigra

hyperkinetic disorders

Abnormal, excessive movements

example: huntingtons

huntingtons disease is caused by

degeneration of the basal nuclei resulting in involuntary jerking, wild flapping motions

limbic system consists of various

diencephalic, subcortical and cortical structure. Some structures of the limbic system include: hypothalamus, and limbic cortex , hippocampus, and amygdala

limbic structures are involved with

emotions and memory functions (thoughts and feelings)

amygdala

nuclei part of the limbic system. interpret facial expressions, body language, and social social signals and is essential for social behavior and motivation. along with cingulate gyrus, the recognition of fear and our response to fearful situations

hippocampus

c shaped structure circling around the thalamus and diencephalon; along with the amygdala, memory processing and storage; retrieval of memory and information

types of memory

declarative, emotional, procedural

declarative memory

refers to recollections that can be easily verbalized (facts, events, locations) it is also called conscious, explicit or cognitive memory

declarative memory has 3 stages

immediate memory, short-term memory, and long-term memory.

cerebral cortex and hippocampus are involved in

declarative memory

emotional memory

remembering feelings; memory for fear involves amygdala and structures unknown to other emotions.

procedural memory

refers to recall of skills and habits (running, swimming) also called unconscious or implicit memory.

Frontal cortex, thalamus and basal nuclei are involved in

procedural memory

cerebral cortex mapping

through testing, injury, loss of function, a generalized mapping of the cerebral cortex has emerged; overlapping functions exist

sensory areas of the cortex

partial ( primary somatosensory)

occipital (vision)

temporal (auditory and olfactory and taste)

motor areas

frontal lobe: primary motor cortex, premotor cortex, Broca’s area. frontal eye field

Association areas

aligned to each primary area and general associations areas

primary sensory areas

somatosensory, auditory, vestibular, visual

primary somatosensory

discriminates shape, texture, or size of object. cortex underlying postcentral gyrus of anterior parietal lobe

primary auditory

discriminates loudness, location and pitch; superior temporal lobe

primary vestibular

discriminates head position and movement for awareness of balance

primary visual

distinguishes intensity of light, shape, size, and location of objects; images from the retina to posterior of occipital lobe

sensory association areas

somatosensory, visual, auditory

sensory somatosensory

stereognosis and memory of tactile and spatial environment; distinguish key in pocket from stick of gum

sensory visual

analysis of motion, color; ex. recognize faces or color

sensory auditory

classification of sounds, ex: thunder or barking

sensory association disorders

agnosia (astereognosis,visual agnosia, auditory agnosia)

agnosia

inability to recognize objects when using a specific sense, even though discriminative ability with that sense is intact

astereognosis

inability to identify objects by touch or manipulation

visual agnosia

inability to identify objects in contralateral visual field

auditory agnosia

inability to recognize sound

association cortex

prefrontal, parietotemporal, limbic

association cortex prefrontal

goal oriented behavior, self awareness, consequence of actions

association cortex parietotemporal

sensory integration, problem solving, understanding language. *wernickes area*

association cortex limbic

emotion, motivation, processing of memory

association cortex disorders

wernickes aphasia: language comprehension is impaired. People with wernickes aphasia can produce spoken sounds, but the speech is meaningless.

Motor areas

primary motor cortex, premotor area, supplementary motor area, broca’s area

Motor areas primary motor cortex

voluntarily controlled movements

Motor areas| premotor area

control of trunk muscles

Motor areas | broca’s area

motor programming of speech, muscles for speech in the left hemisphere and planning nonverbal communication in right hemisphere

supplementary motor areaa

initiation of movement, orientation planning, bimanual and sequential movements

motor areas disorder

apraxia, motor perseveration, broca’s aphasis

apraxia

inability to plan and execute movements and tasks previously known. (strokes, tumors)

motor perseveration

uncontrollable repetition of movement, generally in geriatric patients

brocas aphasia

individuals who know “what they want to stay, they just cannot get it out” brain injury or stroke