bi205- the brain and cranial nerves

about how many neurons does the brain consist of

20 billion

in the fourth week of development 3 primary brain vesicles in the cephalic area of the neural tube enlarge to form…

prosencephalon, mesencephalon, rhombencephalon

during the sixth week of development the prosencephalon and rhombencephalon form…

secondary brain vesicles

prosencephalon forms _______ which form the cerebrum

telencephalon

prosencephalon forms____ which forms the epithalamus, thalamus, and hypothalamus

diencephalon

rhombencephalon forms_____ which forms the cerebellum and pons

metencephalon

rhombencephalon forms____ which forms the medulla oblongata

myelencephalon

mesencephalon forms the…

midbrain

at birth what makes up the lateral ventricle

cerebrum

at birth what makes up the third ventricle

diencephalon

at birth what makes up the cerebral aqueduct

midbrain

at birth what makes up the fourth ventricle

cerebellum and pons

at birth what makes up the fourth ventricle

medulla oblongata (at birth)

relays information to the thalamus and brainstem/regulates heart rate, blood pressure, and digestion

medulla oblongata

relays information to the cerebellum and the thalamus/regulates somatic and visceral motor centers

pons

processes visual and auditory data/maintains consciousness and alertness/involved with reflexive somatic motor responses to stimuli

mesencephalon (midbrain)

contains the pineal gland

epithalamus

relays information to the cerebrum/processes sensory information

thalamus

involved in emotions, thirst, some habitual activity/connects the pituitary gland (hypophysis) via the infundibulum

hypothalamus

coordinates somatic motor function/adjusts output of somatic motor centers resulting in smooth operation

cerebellum

conscious thought processes/intellectual functions, memory storage/conscious regulation of skeletal muscle contractions

cerebrum

what separates the cerebral hemispheres

longitudinal fissure

grooves in the cerebrum

sulci

ridges in the cerebrum

gyri

in the cerebrum and cerebellum the white matter is covered by gray matter

cortex

fluid within the ventricles that transports nutrients to the CNS and transports waste away from the CNS, also provides cushion for the CNS

cerebrospinal fluid (CSF)

located in the cerebral hemispheres

ventricles 1 and 2 (lateral ventricles)

what separates ventricles 1 and 2

septum pellucidum

located in the diencephalon

ventricle 3

lies between the pons and the cerebellum

ventricle 4

how ventricles 1 and 2 communicate with ventricle 3

interventricular foramen

how does the third ventricle communicate with the fourth

cerebral aqueduct

what protects the brain

bones of the skull, cranial meninges, cerebrospinal fluid, blood brain barrier, rich blood supply

most superficial layer of the cranial meninges

dura mater

outermost layer of the dura mater, felt within the anterior fontanelle of a baby, fused to the periosteum lining of the cranial bones

periosteal cranial dura

innermost layer of the dura mater, space between the 2 layers contains large veins called dural sinuses

meningeal cranial dura

meningeal layer that extends into the longitudinal fissure, inferior/anterior portion attaches to the crista galli, inferior/posterior portion attaches to the internal occipital crest and the tentorium cerebrelli, contains the superior sagittal sinus and the inferior sagittal sinus

falx cerebri

separates the cerebellar hemispheres from the cerebral hemispheres, extends across the cranium at right angles to the falx cerebri, contains the transverse sinus

tentorium cerebelli

extends from the tentorium cerebelli to separate to the cerebellar hemispheres

falx cerebelli

lines the sella turcica of the sphenoid bone, anchors the dura mater to the sphenoid bone, encases the pituitary gland

diaphragma sellae

middle layer of the meninges

arachnoid mater

projections in the arachnoid mater that CSF flows through these to enter into venous circulation

arachnoid granulations

space between arachnoid mater and meningeal cranial dura

subdural space

deep to the arachnoid mater

subarachnoid space

innermost meninge, attached to the surface of the brain

pia mater

lining of the blood vessels consists of endothelial cells that are highly interconnected by tight junctions

blood brain barrier

only material that can pass from the blood to the cells of the brain and spinal cord

lipid soluble

regions in the brain where the blood brain barrier is different from the rest of the brain

• hypothalamus

• capillaries in the pineal gland

• capillaries in the choroid plexus

• capillaries in the posterior lobe of the pituitary gland

where is cerebrospinal fluid produced

ependymal cells of the choroid plexus

circulatory disorders in the brain include cerebrovascular diseases such as

cerebrovascular accident (CVA)

nucleus in medulla oblongata that passes somatic sensory information to the thalamus

gracile nucleus and cuneate nucleus

nucleus in medulla oblongata that receives visceral sensation from the spinal nerves and cranial nerves

solitary nucleus

nucleus of the medulla oblongata that pass information from the cerebrum, spinal cord, diencephalon, and brainstem to the cerebellum, create olives (bulges on the medulla oblongata)

olivary nucleus

autonomic nuclei that receives input from cranial nerves, cerebral cortex, diencephalon, and brainstem

reflex centers

major reflex center of cardiac and vasomotor

cardiovascular centers

major reflex center for rhythmic breathing

respiratory rhythmicity centers

the mesencephalon contains pairs of nuclei called

corpora quadrigemina

surface of the mesencephalon that is responsible for processing auditory and visual stimuli

tectum

in the mesencephalon where auditory processing occurs

inferior colliculi

in the mesencephalon where visual processing occurs

superior colliculi

the walls and floor of the mesencephalon that consist of a pair of nuclei called

red nucleus and substantia nigra

the ventrolateral surfaces of the mesencephalon contain the…

cerebral peduncles

epithalamus produces what hormone

melatonin

left and right portions of the thalamus are connected by…

interthalamic adhesion

extends from the hypothalamus and connects the pituitary gland

infundibulum

thalamic nuclei that is part of the limbic system

anterior nuclei

thalamic nuclei that relays information to the frontal lobe

medial nuclei

thalamic nuclei that relays information to the parietal lobes

ventral nuclei

thalamic nuclei that relays information to the occipital lobe

posterior nuclei

thalamic nuclei that adjusts activity in the cingulate gyrus and parietal lobe

lateral nuclei

functions of the hypothalamus

• subconscious control of skeletal muscles

• heart rate, blood pressure, respiration, digestive functions

• secretion of antidiurectic hormones and oxytocin

• emotional and behavioral drives and thirst drives

• coordination between voluntary and autonomic functions

• body temperature

• circadian rhythm

part of the hypothalamus that controls the secretion of antidiurectic hormones

supraoptic nucleus

portion of hypothalamus the controls secretion of oxytocin

paraventricular nucleus

portion of hypothalamus that controls body temperature

pre-optic area

portion of the hypothalamus that controls circadian rhythm

suprachiasmatic nucleus

folds in the cerebellum that are similar to the gyri of the cerebrum

folia of the cerebellum

what separates the anterior and posterior lobes of the cerebellum

primary fissure

narrow band of cortex that separates the 2 hemispheres of the cerebellum

vermis

in the cerebellum and controls subconscious coordination of movements

cerebellar cortex

connects the cerebellar cortex with cerebellar peduncles

arbor vitae

connect the cerebellum with the mesencephalon, diencephalon and cerebrum

superior cerebellar peduncle

communicate between cerebellum and pons

middle cerebellar peduncle

connect cerebellum with the medulla oblongata

inferior cerebellar peduncle

lobe responsible for conscious control of skeletal muscles

frontal lobe

lobe responsible for the perception of visual stimuli

occipital lobe

lobe responsible for conscious perception of touch, pressure, vibration, pain, temperature, and taste

parietal lobe

lobe responsible for conscious perception of auditory and olfactory stimuli/deep is the insula

temporal lobe

anterior to the central sulcus, neurons direct voluntary movements by controlling somatic motor neurons in the brainstem and spinal cord, consists of primary motor complex and pyramidal cells

precentral gyrus

consists of the primary somatosensory cortex, posterior to the central sulcus, neurons receive somatic sensory info for touch, pressure, pain, taste and are associated with visual cortex, auditory cortex, olfactory cortex, and gustatory cortex

postcentral gyrus

allows for the understanding of size, form, and texture

somatosensory association area

uses memories of learned movement to coordinate motor activities

premotor cortex

visually recognizes and interprets objects

visual association area

recognizes sound

auditory association area

characteristics of higher-order functions

• performed by the cerebral cortex

• involve communication between cerebral cortex areas and other areas of the brain

• involve conscious and unconscious info processing

• functions are subject to modifications and adjustments

integrate complex sensory stimuli and complex motor responses

integrative centers

this area consists of the speech center, prefrontal cortex, and wernicke’s area

cerebral cortex

analytical area'/plays a role in personality

Wernicke’s area

speech production, regulates breathing pattern for speech

speech center (Broca’s area)

performs complicated learning and reasoning functions, a lobotomy is the removal of this

prefrontal cortex

what is the left hemisphere responsible for

speech center, writing, language, math