neuro - chpt 14

brain & cranial nerves pt 1

falx cerebri

sagittal sickle shape reflextion of dura matter

• longitudinal fissure in cerebrum & partially separates cerebral hemispheres

• divides 2 hemipheres of cerebrum

Tentorium cerebelli

tent like horizontal sheet

• intervenes btwn cerebellum & occipital lobe

• divides cerebrum / cerebellum

falx cerebelli

less prominent vertical reflection of dura in sagittal plane

• along vermis that partially separates cerebellar hemispheres

• divides 2 hemispheres of cerebellum

internal carotid & vertebral arteries

• forms circle of willis

arterial blood supply to brain (2)

astrocytes

keeps endothelial cells of blood brain capillaries tight

• secrete chemicals that maintain permeability of tight junctions

choroid plexus

produces CSF

• located in all cerebral ventricles

• covered by ependymal cells

medulla oblongata / medulla

inferior part of brainstem connecting to spinal cord

• pyramidal tracts

• olive (olivary nucleus for proprioception)

• CN IX-XII

• white & gray matter → superior ½ gray matter imbedded in white as clusters of nuclei

nuclei of grey matter in Medulla oblongata

• gustatory nucleus (taste)

• cochlear nuclei (hear)

• vestibular nuclei (balance)

• cardiovascular center

• medullary resp. center (cough, sneeze, hiccup)

• vomiting center

• deglutination center

inferior olivary nucleus

info for cerebellum of new motor skills

• in medulla oblongata

nucleus gracilis & cuneatus

associated w/ medial lemniscus tract (post. column pathway; fine touch)

• in medulla oblongata

pons

cerebellum behind, medulla inferior, midbrain superior

• contains basilar sulcus (basilar artery)

• CN V-VIII

• pontine respiratory group (+medulla = controls breathing)

midbrain

pons inferior, diencephalon superior

• cerebral peduncles = has crus cerebri

• superior/inferior colliculi = relay center for visual/auditory reflexes (respectivley)

• CN III-V

• red nucleus (rubrospinal tract)

• substantia nigra (associated w/ parkinsons)

  • PAG (periaqueductal gray matter) = produce natural painkillers (endorphins & enkephalins)

crus cerebri

2 columns of ant. aspect in midbrain (cerebral peduncles) that contain descending tracts: corticospinal & corticobulbar tracts

Reticular activating system (RAS)

ascending part of Reticular Formation (projects in cerebral cortex)

• helps maintain consciousness by visual & auditory stimuli & mental activities

active during:

• arousal, attention/alertness, preventing sensory overload

• NO SMELL RECEPTOR INPUT

cerebellum

consists of 2 cerebellar hemispheres connected by vermis

anteiror & posterior lobes of cerebellum

lobes that governs subconscious aspects of skeletal mvnts

floculondondular lobe of cerebellum

lobe that regulates equilibrium & balance

supeior cerebellar peduncles

carry axons that connect cerebellum to red nucleus of midbrai/thalamus

middle cerebellar peduncles

connects pontine nuclei of pons to cerebellum

inferior cerebellar peduncles

carry bundles of axons travelling btwn medulla & cerebellum (ex. spinocerebellar tracts)

primary function of cerebellum

primary functions:

• coordination of voluntary mvnts

• maintaining posture / balance

(mvmnt: intention, actual, comparing command signals w/ sensory info, correcting discrepancies)

ataxia

abnormal coordination of mvmnt

• damage to cerebellum

primary function of thalamus

primary function:

• consciousness, sleep, attention, memory, sensory/motor functions

• relays all senses BUT SMELL to cerebral hemispheres

• autonomic nervous system = emotion, body temp, eating, drinking

amygdaloid body

controls behaviors, mood, emotion (in limbic system)

hippocampus

involved in learning new infor & recent memory (in limbic system)

broca’s area

generates motor signals for vocal apparatus

• located in frontal lobe

• 97% of population found in left cerebral hemiphere

damage = nonfluent aphasia (understand but cant speak)

wernicke’s area

understanding language

• end of lateral sulcus in L temporoparietal junction

damage = receptive/sensory/fluent aphasia (jumbled meaningless words)

prefrontal cortex

makeup of person’s personality, intellect, complex learning abilities, recall of info, initiative, judgment, foresight, reasoning, conscience, intuition, mood, planning of future, development of abstract ideas