ANA 209 chapter 15- Adler

insula

Involved in memory and interpretation of taste

parietal lobe

Involved with general sensory functions

temporal lobe

Involved with hearing and smell

caudate nucleus

produces patterned arm and leg movements associated with walking

falx cerebri

projects into longitudinal fissure and separates left and right cerebral hemispheres

medulla oblongata

the most inferior part of the brainstem, is formed from the myelencephalon. It continues with the spinal cord inferiorly.

tectum

the posterior region of the mesencephalon dorsal to the mesencephalic aqueduct. It contains the tectal plate (quadrigeminal plate) containing the superior colliculi (visual reflex centers), and the inferior colliculi (auditory reflex centers).

Fornix

thin tract of white matter that connects hippocampus with other diencephalon limbic system structures

diencephalon (diagram)

components: hypothalamus thalamus epithalamus

lentiform nucleus

composed of putamen and globus pallidus

claustrum

processes visual information at a subconscious level

visual association area

processes visual information; located in the occipital lobe

three regions of the cerebellum

1. An outer gray matter layer of cortex 2. An internal region of white matter, called the arbor vitae 3. Cerebellar nuclei in the deepest layer

Production and Circulation of Cerebral Spinal Fluid

1. CSF is produced by the choroid plexus in the ventricles 2. CSF flows from the third ventricle through the cerebral aqueduct into the fourth ventricle 3. CSF in the fourth ventricle flows into the subarachnoid space by passing through the paired lateral apertures of the single median aperture, and into the central canal of the spinal cord 4. as CSF flows through the subarachnoid space, it removes waste products and provides buoyancy to support the brain 5. excess CSF flows into the arachnoid villi, then drains into the dural venous sinuses. pressure allows the CSF to be released into the blood without permitting any venous blood to enter the subarachnoid space. the greater pressure on the CSF in the subarachnoid space ensures that CSF moves into the venous sinuses

motor areas, sensory areas, association areas

3 functional areas of the cerebral cortex

dura mater, arachnoid mater, pia mater

3 layers of meninges

vermix

A narrow band of cortex along the midline of the cerebellum separates the left and right cerebellar hemispheres. receives sensory input on the torso position and balance. Its output to the vestibular nucleus helps maintain balance.

interthalamic adhesion (or intermediate mass)

A small midline mass of gray matter that connects the right and left thalamic bodies

fissures

Adjacent gyri are separated by shallow sulci or deeper grooves called:

tracts that ascend or descend through the medulla oblongata

All communication between the brain and spinal cord involves:

medial lemniscus

Bands of myelinated fibers composing a ______exit the nucleus cuneatus and the nucleus gracilis and decussate in the inferior region of the medulla oblongata. The medial lemniscus projects through the brainstem to the ventral posterior nucleus of the thalamus.

functions of CSF

Buoyancy—the brain floats in the CSF Protection—CSF provides a liquid cushion from sudden movements Environmental stability—CSF transports nutrients and removes waste from the brain

cerebellar hemispheres

Cerebellum composed of left and right:

brainstem

Connects the forebrain and cerebellum to the spinal cord Is a bidirectional passageway for all tracts extending between the cerebrum and the spinal cord Contains many autonomic centers and reflex centers required for survival Houses nuclei of many of the cranial nerves

cerebellar functions

Coordinates and fine-tunes skeletal muscle movements and ensures that skeletal muscle contraction follows the correct pattern leading to smooth, coordinated movements Stores memories of previously learned movement patterns Adjusts skeletal muscle activity to maintain equilibrium and posture Receives proprioceptive (sensory) information from the muscles and joints and uses this information to regulate the body's position Monitors the position of each body joint and its muscle tone

rostral and caudal

Directional Terms to Describe the Brain

anterior; posterior; primary fissure

Each cerebellar hemisphere consists of two lobes, _____ lobe and _____ lobe, separated by _______

thalamic nuclei

Each part of the thalamus is a gray matter mass composed of about a dozen or more _____ with axons projecting to particular regions of the cerebral cortex.

location and formation of parietal lobe

Forms the superoposterior part of each hemisphere and underlies the parietal bone Terminates anteriorly at the central sulcus, laterally at the lateral sulcus, and posteriorly at the parieto-occipital sulcus

olive; inferior olivary nucleus

Immediately lateral to each pyramid is a bulge called the ____, which contains gray matter called the _____. These nuclei relay ascending sensory impolses, especially proprioceptive information, to the cerebellar cortex.

functions of hypothalamus

Master control of the autonomic nervous system Master control of the endocrine system Regulation of body temperature Control of emotional behavior Control of food intake Control of water intake Regulation of sleep-wake (circadian) rhythms

CN III ; CN IV

Nuclei of oculomotor nerve ___ and trochlear nerve ___ are housed in the mesencephalon

gray matter, white matter

Organization of Neural Tissue Areas in the Brain

epithalamus

Partially forms posterior roof of the diencephalon and covers the third ventricle components include pineal gland and habenular nuclei

Higher-Order Processing Centers

Process incoming information from several different association areas Ultimately direct either extremely complex motor activity or complicated analytical functions Involve functions such as speech, cognition, understanding spatial relationships, and general interpretation Housed in both cerebral hemispheres

occipital lobe

Processes incoming visual information Stores visual memories

cerebellum

Second largest part of the brain Develops from the metencephalon

brain and spinal cord

Sensory and motor tracts are housed within the pons that connect to the _____

thalamus, nuclei

Sensory impulses from all conscious senses except olfaction converge on the _____ and synapse in at least one of its ____

flocculonodular lobes

Slender_____ lie anterior and inferior to each cerebellar hemisphere.

cerebral peduncles

Somatic motor axons descend from the primary motor cortex through the ________ (located on the anterolateral surfaces of the mesencephalon) to the spinal cord

memory; consciousness

Some aspects of cortical function, such as _____ or _____, cannot easily be assigned to any single region

mesencephalon

Superior portion of brainstem

choroid plexus hypothalamus pineal gland

The BBB is markedly missing or reduced in three distinct locations of the CNS:

Caudal

The ____ portion of the medulla oblongata resembles the spinal cord.

pyramids

The anterior surface exhibits two longitudinal ridges called the ____, which house the motor projection tracts called the corticospinal tracts.

rostrally

The central canal of the spinal cord extends ____ through the medulla and enlarges to become the fourth ventricle.

cerebral hemispheres

The cerebrum is composed of two halves called left and right _____

tracts

The hemispheres are separate from one another except at a few locations where bundles of axons called _____ form white matter regions that allow for communication between them

nucleus cuneatus; nucleus gracilis

The medulla oblongata contains the ______ and the _____, which relay somatic sensory information to the thalamus.

longitudinal fissure

The paired cerebral hemispheres are divided by a _____ that extends along the midsagittal plane

CN V; CN VI; CN VII; CN VIII

The pons houses sensory and motor cranial nerve nuclei for the trigeminal _____, abducens ____, and facial ____ cranial nerves. Some of the nuclei for the vestibulocochlear cranial nerve ____ are located in the pons.

gyri

The surface of the cerebrum folds into elevated ridges called:

sensory, somatosensory

The thalamus is a principal and final relay point for ____ information that will be processed and projected to the______ cortex.

infundibulum

The thin, stalklike _____ extends inferiorly from the hypothalamus to attach to the pituitary gland.

hemisphere lateralization

The two hemispheres appear as anatomic mirror images, but they display some functional differences, termed:

CN VIII; CN IX; CN X; CN XI; CN XII

Within the medulla oblongata are cranial nerve nuclei associated with the vestibulocochlear _____, glossopharyngeal ______, vagus ____, accessory ____, and hypoglossal ____ cranial nerves.

opposite sides of the body

With few exceptions, both cerebral hemispheres receive their sensory information from and project motor commands to:

cerebrospinal fluid (CSF)

a clear, colorless liquid that circulates in the ventricles and subarachnoid space

considerable overlap and indistinct boundaries

__________ permit a single region of the cortex to exhibit several different functions.

precentral gyrus

a mass of nervous tissue in the frontal lobe immediately anterior to the central sulcus

Hippocampus

a nucleus shaped like a seahorse; essential in storing memories and forming long-term memory

other nuclei in the medulla oblongata

are involved in coughing, sneezing, salivation, swallowing, gagging, and vomiting

Telencephalon

arises from prosencephalon, eventually forms cerebrum

Metencephalon

arises from rhombencephalon, eventually forms the pons and cerebrum

tegmentum

between the substantia nigra and the periaqueductal gray matter. contains the red nuclei and the reticular formation. integrates information from the cerebrum and cerebellum and issues involuntary motor commands to the erector spinae muscles of the back to maintain posture.

pons

bulging region on the anterior part of the brainstem that forms from part of the metencephalon.

outer layer of cerebrum

called the cerebral cortex and is gray matter

components of cerebral nuclei

caudate nucleus amygdaloid body lentiform nucleus claustrum corpus striatum

ventricles

cavities or expansions within the brain that are continuous with one another and the central canal of the spinal cord. All contain cerebral spinal fluid. There are four in the brain

internal layer of cerebrum

cerebral white matter

Motor Speech Area (Broca's Area)

controls muscular movements necessary for vocalization; located in most individuals within the inferolateral portion of the left frontal lobe

superior cerebellar peduncle

connect the cerebellum to the mesencephalon

inferior cerebellar peduncle

connect the medulla oblongata to the cerebellum

cranial meninges

connective tissue layers that: Separate soft tissue of the brain from bones of cranium enclose and protect blood vessels that supply the brain contain and circulate cerebrospinal fluid form some of the veins that drain blood from the brain

substantia nigra

consists of bilaterally symmetrical nuclei with the mesencephalon. houses clusters of neurons that produce the neurotransmitter dopamine, which affects brain processes that control movement, emotional response, and the ability to experience pleasure and pain. Degeneration of cells in it is a pathology that underlies Parkinson disease.

Capillary endothelial cells and astrocyte perivascular feet

contribute to BBB

motor areas of cerebrum

control voluntary motor functions

frontal eye field

controls and regulates eye movements and binocular vision; located on the superior surface of the middle frontal gyrus, immediately anterior to the premotor cortex

vasomotor center of medulla oblongata

controls blood pressure by regulating the contraction and relaxation of smooth muscle in the walls of arterioles

primary motor cortex (somatic motor area)

controls voluntary skeletal muscle activity; located within the precentral gyrus; axons project contralaterally to the brainstem and spinal cord; innervation to various body parts can be diagrammed as a motor homunculus on the precentral gyrus

frontal lobe location

deep to the frontal bone and forms anterior part of cerebral hemisphere Ends posteriorly at the central sulcus; inferior border marked by the lateral sulcus

location of insula

deep to the lateral sulcus

diencephalon

derives from prosencephalon, eventually forms thalamus, hypothalamus, and epithalamus

myelencephalon

derives from rhombencephalon, eventually forms medulla oblongata

globus pallidus

excites and inhibits activities of thalamus to control and adjust muscle tone

Amygdaloid body

expression of emotions, control of behavioral activities, development of moods

cerebral aqueduct

extends through the mesencephalon and connects third and fourth ventricles surrounded by periaqueductal gray matter

habenular nuclei

help relay signals from the limbic system to the mesencephalon and are involved in visceral and emotional responses to odor

tentorium cerebelli

horizontal fold that separates cerebrum from cerebellum; anterior surface has a gap (tentorial notch) to allow for passage of brainstem

gray matter

houses motor neuron and interneuron cell bodies, dendrites, telodendria, unmyelinated axons forms the cortex, which covers the surface of most of the adult brain forms discrete internal clusters called cerebral nuclei

Volume: 1200-1500 cc Weight: 1.35-1.4 kg

human brain size

autonomic respiratory centers

in the pons the pneumotaxic center and the apneustic center regulate the rate and depth of breathing, and influence the activity of the respiratory center in the medulla oblongata.

location of occipital lobe

in the posterior region of each hemisphere underlying the occipital bone

location of temporal lobe

inferior to the lateral sulcus underlying the temporal bone

association areas of cerebrum

integrate and store information

Gnostic area (common integrative area)

integrates all sensory, visual, and auditory information; composed of regions of the parietal, occipital, and temporal lobes

Somatosensory association area

integrates and interprets sensory information; located in parietal lobe immediately posterior to post central gyrus

Various nuclei in the diencephalon (anterior thalamic nuclei, habenular nuclei, septal nuclei, mammillary bodies)

interconnect other parts of the limbic system and contribute to overall function

limbic system (diagram)

interconnect other parts of the limbic system and contribute to overall function

cingulate gyrus

internal mass of cerebral cortex located within the longitudinal fissure and superior to the corpus callosum; receives input from the other components of the limbic system

auditory association area

interprets characteristics of sound and stores memories of sound; located within temporal lobe posteroinferior to the primary auditory cortex

amygdaloid body

involved in several aspects of emotion, especially fear; helps sort and code memories based on how they are emotionally perceived

frontal lobe

involved with voluntary motor function, concentration, verbal communication, decision making, planning, and personality

postcentral gyrus

is a mass of nervous tissue in the parietal lobe immediately posterior to central sulcus

1. Frontal Lobe 2. Parietal Lobe 3. Temporal Lobe 4. Occipital Lobe 5. Insula

lobes of the cerebrum

white matter

made up of myelinated axons lies deep to the gray matter of the cortex

Cerebrum Diencephalon Brainstem Cerebellum

major regions of the brain

parahippocampal gyrus

mass of cortical tissue associated with the hippocampus

superior olivary complex

nuclei are located in the pons. This nuclear complex receives auditory input and involves pathways for sound localization.

primary gustatory cortex

processes taste information; located in insula

lateral ventricles

one in each hemisphere of the cerebrum, separated by a thin septum pellucidum

Mesencephalon

only primary vesicle that does not form a new secondary vesicle

cerebral nuclei

paired irregular masses of gray matter buried deep within the central white matter in the basal region of the cerebral hemispheres inferior to the floor of the lateral ventricles.

thalamus

paired oval masses of gray matter that lie on each side of the third ventricle.

Olfactory bulbs, olfactory tracts, olfactory cortex

particular odors can provoke certain emotions or be associated with certain emotions

cranial dural septa

partition separate specific parts of the brain and provide stabilization and support: falx cerebri tentorium cerebelli falx cerebelli diphragma selae

falx cerebelli

partition that separates left and right cerebellar hemispheres

Premotor cortex (somatic motor association area)

processes motor information and coordinates learned skilled motor activities; located in frontal lobe immediately anterior to precentral gyrus

sensory areas of cerebrum

provide conscious awareness of sensation

primary olfactory cortex

provides conscious awareness of smell; located in temporal lobe

primary auditory cortex

receives and processes auditory information; located in temporal lobe

primary visual cortex

receives and processes incoming visual information; located in occipital lobe

Primary somatosensory cortex

receives general somatic sensory information from touch, pressure, pain, and temperature receptors; located within the postcentral gyrus; sensory homunculus may be traced on surface

nucleus gracilis

receives sensory innervation from the lower limbs.

nucleus cuneatus

receives sensory innervation from the upper limbs of the same side

Wernicke's area

recognizes and comprehends spoken and written language; typically located within left hemisphere where it overlaps the parietal and temporal lobes

cardiac center of medulla oblongata

regulates heart rate and its strength of contraction

respiratory center of medulla oblongata

regulates respiratory rate and is influenced by the apneustic and pneumotaxic centers of the pons

dural venous sinuses

run within the margins of the dural septa

transverse sinuses

run within the posterior border of the tentorium cerebelli

occipital sinus

runs in the posterior vertical border of the falx cerebelli

inferior sagittal sinus

runs within the inferior margin of the falx cerebri

superior sagittal sinus

runs within the superior margin of the falx cerebri

pineal gland

secretes melatonin, a hormone that helps regulate day-night cycles (circadian rhythm)

diaphragma selae

small septum between pituitary and hypothalamus

blood-brain barrier

strictly regulates what substances can enter the interstitial fluids of the brain

corpus striatum

striped appearance of internal capsule as it passes among the caudate nucleus and lentiform nucleus

limbic system

structures form a ring around around the diencephalon composed of multiple cerebral and diencephalic structures that collectively process and experience emotions. affects memory formation through the integration of past memories of physical sensations with emotional states.

putamen

subconscious muscular movement

hypothalamus

the anteroinferior region of the diencephalon

folia

the cerebellum has a complex, highly convoluted surface covered by a layer of cerebellar cortex with folds called

corpus callosum

the largest tract and the main tract that connects the two cerebral hemispheres

cerebrum

the location of conscious thought processes and the origin of intellectual functions contains a large number of neurons that are needed for complex analytical and integrative functions.

fifth week of development

the three primary vesicles further develop into five secondary brain vesicles by the:

cranial nerves

there are 12 pairs They are numbered with Roman numerals by their position, beginning with the most anteriorly placed nerve. Their names are generally related to function.

Prosencephalon (forebrain) Mesencephalon (midbrain) Rhombencephalon (hindbrain)

three primary brain vesicles

late 4th week of development

three primary brain vesicles have formed by the:

1. Mesencephalon 2. Pons 3. Medulla Oblongata

three regions of the brain stem

cerebellar peduncles

three thick tracts that link the cerebellum with the brainstem

rostral

toward the nose (synonymous with anterior)

caudal

toward the tail (synonymous with posterior)

middle cerebellar peduncle

transverse fibers that connect the pons to the cerebellum.

fourth ventricle

ventricle between the pons and cerebellum

third ventricle

ventricle of the diencephalon