LECTURE 7 brain Flashcards
description of the brain
part of CNS, contained in cranial cavity, made of nervous tissue
components of nervous tissue of brain
gray matter surrounded by white matter with outer cortex of gray matter
4 parts of brain
cerebrum, cerebellum, diencephalon, brain stem
3 parts of brain stem
midbrain, pons, medulla oblongata
what are meninges of brain made of?
made of connective tissue
functions of meninges of brain
cover and protect CNS; enclose, protect blood vessels supplying CNS; contain CSF
3 layers of meninges of brain
dura mater (superficial), arachnoid mater (middle), pia mater (deep)
description of dura mater of meninges of brain
strongest, fibrous connective tissue; bilayered; layers fused except around dural sinuses
2 layers of dura mater of meninges of brain
periosteal layer (periosteum), meningeal layer
description of periosteal layer of dura mater of meninges of brain
external/superficial layer, fused to cranial bones
description of meningeal layer of dura mater of meninges of brain
internal/deep layer, up against arachnoid mater
definition of extensions of dura mater of meninges of brain
partitions: limit movement of brain
falx cerebri
extension of dura mater of meninges of brain: vertical, between cerebral hemispheres
falx cerebelli
extension of dura mater of meninges of brain: vertical, between cerebellar hemispheres
tentorium cerebelli
extension of dura mater of meninges of brain: horizontal, between cerebrum and cerebellum
description of arachnoid mater of meninges of brain
middle layer, contains subarachnoid space and arachnoid villi
description of subarachnoid space of arachnoid mater of meninges of brain
between arachnoid mater and pia mater, created from arachnoid rootlets, contains most of CSF, blood vessels
description of arachnoid villi of arachnoid mater of meninges of brain
also called granulations, projections of arachnoid mater through dura mater into superior sagittal sinus, act as valves to help CSF pass into dural sinuses (don’t exist in arachnoid mater of meninges of spinal cord)
description of pia mater of meninges of brain
innermost layer, delicate and highly vascularized, clings directly to brain tissue and dips into sulci
descriptions of ventricles of brain
expansions of brain’s central cavity, lined with ependymal cells (neuroglial cells), filled with CSF (CSF created in the ventricles)
ventricles of the brain are continuous with:
each other, central canal of spinal cord, subarachnoid space
4 ventricles of brain
2 lateral ventricles, third ventricle, fourth ventricle
description of 2 lateral ventricles of brain
within cerebral hemispheres, separated by septum pellucidum (thin wall of gray matter), symmetrical to each other on either hemisphere (R&L)
description of third ventricle of brain
within diencephalon
description of interventricular foramen of brain
connects third and lateral ventricles of brain
description of fourth ventricle of brain
within hindbrain (between brainstem and cerebellum), connects to central canal of spinal cord
description of cerebral aqueduct of brain
connects third and fourth ventricles of brain
3 openings that connect fourth ventricle of brain to subarachnoid space
2 lateral apertures, 1 median aperture
description of cerebrospinal fluid
forms as a filtrate of blood in choroid plexuses of ventricles (group of capillaries surrounded by ependymal cells within ventricles), 1/2 cup circulating at one time, “floating the brain”
cerebrospinal fluid contains:
sodium, chloride ions, proteins, glucose, oxygen
functions of cerebrospinal fluid
liquid cushion for brain and spinal cord, nourishes brain, removes waste, conducts chemical signals between parts of CNS (eg: hormones)
flow of cerebrospinal fluid
formed in choroid plexuses of each ventricle, moves through ventricles, into subarachnoid space and central canal from fourth ventricle, through arachnoid villi into superior sagittal sinus, into internal jugular vein
description of blood brain barrier
endothelium (simple squamous epithelium) of brain capillaries are loaded with tight junction to decrease permiability (not completely impermeable, some things still have to get through, like fat-soluble molecules)
function of blood brain barrier
protects brain from blood-born toxins (eg: urea, food toxins, bacteria–all metabolic waste)
description of cortex of brain
external sheets of gray matter in cerebrum and cerebellum
description of nuclei of brain
deep masses of gray matter surrounded by white matter (aka basal gangliae)
description of cerebrum of brain
“executive suite” of nervous system, largest portion of brain (83%), most superior region of brain, contains cerebral cortex with many sulci forming gyri, contains fissures
functions of cerebrum of brain
self awareness, initiates and controls voluntary movements, communication, memory, understanding, language, emotion
description of sulci of cerebral cortex of brain
shallow grooves on surface of brain
description of gyri of cerebral cortex of brain
ridges on brain tissue formed by the sulci
2 fissures of cerebrum of brain
transverse cerebral fissure, longitudinal fissure
description of transverse cerebral fissure of cerebrum of brain
separates cerebral hemispheres from cerebellum
description of longitudinal fissure of cerebrum of brain
separates right and left cerebral hemispheres
description of cerebral hemispheres of cerebrum of brain
2 hemispheres control opposite sides of body, corpus callosum is largest commissure between the hemispheres, each hemisphere has 5 lobes
5 lobes of each hemisphere of cerebrum of brain
frontal, parietal, occipital, temporal, insula
function of frontal lobe of cerebrum of brain
motor and premotor
function of parietal lobe of cerebrum of brain
somatosensory
function of occipital lobe of cerebrum of brain
primary visual area
function of temporal lobe of cerebrum of brain
primary auditory area
function of insula lobe of cerebrum of brain
integration of information from other 4 lobes
function of left hemisphere of cerebrum of brain
language, mathematics, logic
function of right hemisphere of cerebrum of brain
visual-spacial, interpreting facial expressions, intuition, emotion, artistic/musical skills
description of diencephalon of brain
surrounded by cerebral hemispheres, made of 3 paired structures: thalamus, hypothalamus, epithalimus
description of thalamus of diencephalon of brain
“gateway”, communicates sensory information of cerebral cortex
description of hypothalamus of diencephalon of brain
regulates many body activities, emotion, sleep, memory, contains pituitary gland (endocrine, growth hormone, thyroid stimulating hormone)
description of epithalamus of diencephalon of brain
much smaller than thalamus and hypothalamus, contains pineal gland (endocrine, melatonin)
function of brainstem of brain
passage of all signals between spinal cord and brain
components of brainstem of brain
midbrain, pons, medulla oblongata
description of midbrain of brainstem of brain
most cranial, visual and auditory reflex center, attachment for CN III, IV
description of pons of brainstem of brain
middle portion of brainstem, attachment for CN V, VI, VII, VIII
description of medulla oblongata of brainstem of brain
most caudal, regulates several basic physiological functions, attachment of CN IX, X, XI, XII
description of cerebellum of brain
divided into hemispheres (each made of 3 lobes), cerebellar cortex surrounds white matter (arbor vitae)
functions of cerebellum of brain
smooth and coordinate body movements using information on equilibrium and voluntary movement of neck, trunk, and limbs; helps learn new motor skills
arteries of the brain
external carotid arteries and branches, internal carotid arteries and branches, vertebral arteries
veins of the brain
dural sinuses, internal jugular vein, external jugular vein, vertebral vein
