H13: Brain

cerebrum

Largest part of the brain consisting of 2 hemispheres

sulci (sulcus, singular)

grooves on the surface of the cerebrum

Gyri (gyrus, singular)

elevated ridges

convolutions of the cerebrum separated by sulci

longitudinal fissure

occupied?

deep groove that separates cerebral hemispheres

occupied by the falx cerebri

transverse fissure or sulcus

occupied by?

separates the cerebrum and cerebellum and is occupied by the tentorium cerebelli

lateral fissure or sulcus

Separates the temporal lobe from the rest of the cerebrum superior to it

central sulcus

separates the precentral(motor) and postcentral (sensory) gyri

NOT FISSURE

4 major sulci(or fissures) are: _________________

1. longitudinal fissure

2. transverse fissure or sulcus

3. lateral fissure or sulcus

4. central sulcus

four main lobes of cerebrum

frontal, parietal, temporal, occipital

fifth lobe of cerebrum

insula

lies within depths of lateral sulcus

insula

cerebral lobe located deep within lateral sulcus

primary motor cortex

pre-central gyrus

lies anterior to central sulcus

stimulated when you decide to move a structure

primary sensory cortex

post-central gyrus

lies posterior to central sulcus

when you feel something, this is stimulated

homonculus

basal nuclei (ganglia)

constitute?

control?

diseases?

constitute the central gray matter of the cerebrum

control of movement and posture

Diseases involved disturbances in voluntary muscular control, eg. Parkinson's disease, Huntington's Chorea

diseases of basal nuclei

Diseases involved disturbances in voluntary muscular control, eg. Parkinson's disease, Huntington's Chorea

thalamus

purpose?

sends?

location to it what?

most important sensory relay center of the brain

sends incoming impulses from the receptors of the body to the cerebral cortex

posterior to the thalamus is the pineal gland (pineal body)

pineal gland (pineal body)

secretes?

posterior to the thalamus

secretes melatonin, involved in sleep wake cycle

hypothalamus: what does it lie between and is associated with

it lies between and is associated with the:

A. optic chiasma

B. mamillary bodies

C. pituitary gland

hypothalamus: functions

functions in the regulation of visceral activity

1. Body temperature

2. Carbohydrate and lipid metabolism

3. Sleep, sexual activity and emotions

optic chiasma

the crossing of the optic nerves, CNII, from the two eyes at the base of the brain

mammillary bodies

part of?

sensory synaptic station part of limbic system

pituitary gland

projects from where?

projects inferior from the hypothalamus and secretes many hormones

brainstem

3 parts from superior to inferior:

midbrain

pons

medulla oblongata

midbrain

contains:

anterior?:

posterior?:

contains the cerebral peduncles anteriorly and the tectum (or roof) of the corpora quadrigemina posteriorly

cerebral peduncles

located in the midbrain

corpora quadrigemina

located in the midbrain

consists of 4 elevations that are arranged as two pairs:

Superior colliculi

Inferior colliculi

superior colliculi

involved in pathway of vision

in corpora quadrigemina in the midbrain

(eyes are higher than ears)

inferior colliculi

involved in the pathway of hearing

in corpora quadrigemina in the midbrain

(eyes are higher than ears)

pons

what does it do?

what does it connect?

acts as a bridge connecting the right and left cerebellar hemispheres

relays impulses from the cerebral cortex to the cerebellum

medulla oblongata

part of the brain that is _________ with the spinal cord

contains most of the ____ and ____ of the spinal cord

represents an area where ______ lie, called the ______.

An area inferior to this is where the ________ cross or decussate over to the ______ side. This is called the __________

Other tracts can cross either in the ____ or in the _____itself

part of the brain that is directly continuous with the spinal cord

contains most of the ascending and descending tracts of the spinal cord

represents an area where pyramidal tract fibers lie, called the PYRAMIDS.

An area inferior to this is where the pyramidal tracts cross or decussate over to the contralateral side. This is called the pyramidal decussation.

Other tracts can cross either in the spinal cord or in the brain itself

pyramidal decussation

The pyramidal decussation marks the border between the spinal cord and the medulla oblongata.

where the pyramidal tracts cross or decussate over to the contralateral side

WITHIN THE MEDULLA OBLONGATA

pyramids of medulla oblongata

pyramidal tract fibers

other than the pyramidal decusation where can tracts cross?`

spinal cord or brain itself

medulla oblongata contains several nuclei involved in:

regulation of vital body activities: respiratory, cardiac (heart rate), and vasomotor (blood pressure)

• B = Breathing → respiratory center

• H = Heart rate → cardiac center

• B = Blood pressure → vasomotor center

cerebellum: SUMMARY

little brain

It connects with the midbrain, pons, and medulla oblongata via the superior, middle and inferior cerebellar peduncles

It consists of two hemispheres separated by a median vermis

Its outer cortex contains folia separated by fissures, folia means leaves, just like the brain, how it has gyri separated by sulci, we say that the cerebellum has folia separated by fissures.

internally presents white matter branching in the form of a tree, called arbor vitae

functions: coordination of muscular activity, regulation of muscle tone, maintenance of equilibrium

cerebellum connects with ______ via _____

It connects with the midbrain, pons, and medulla oblongata via the superior, middle and inferior cerebellar peduncles

peduncles of cerebellum

superior, middle, inferior

median vermis

Connects the two hemispheres of the cerebellum

cerebellum outer cortex contains

folia separated by fissures, folia means leaves, just like the brain, how it has gyri separated by sulci, we say that the cerebellum has folia separated by fissures.

cerebellum internally presents _____

internally presents white matter branching in the form of a tree, called arbor vitae

functions of cerebellum

1. coordination of muscular activity

2. regulation of muscle tone

3. maintenance of equilibrium

• A = muscular Activity

• T = Tone of muscles

• E = Equilibrium → balance

arbor vitae

white matter of the cerebellum