Anatomy and Physiology 2 Brain Structure and Function lab quiz

Identification of Major Brain Regions

There are four major brain regions

Cerebrum

It is large, is the dominant brain structure, with many folds and crevices enveloping the diencephalon.

Cerebellum

Posterior to the brain stem.

Diencephalon

Superior to the brain stem in the center of the brain.

Brain stem

Connected to the superior part of the spinal cord.

The Brain Stem (Sagittal section, medial view)

It is composed of 3 structures.

Corpora quadrigemina

Composed of 2 superior colliculi and 2 inferior colliculi.

Midbrain

A smaller area superior to the pons and inferior to the diencephalon, consisting of cerebral peduncles and the corpora quadrigemina.

Pons (Bridge)

An expanded structure located superior to the medulla oblongata and anterior to the cerebellum, and has respiratory centers that assist the medulla oblongata in controlling breathing.

Medulla oblongata

The first brain structure, is immediately superior to the spinal cord and is the most vital part of the brain because it houses the respiratory and cardiovascular control centers.

Cerebral peduncle

White fibers that connect the upper and lower brain areas.

The Brain Stem (Inferior aspect of brain)

Posterior view continued

Midbrain

A smaller area superior to the pons and inferior to the diencephalon, consisting of cerebral peduncles and the corpora quadrigemina.

Pons (Bridge)

An expanded structure located superior to the medulla oblongata and anterior to the cerebellum, and has respiratory centers that assist the medulla oblongata in controlling breathing.

Medulla oblongata

The first brain structure, is immediately superior to the spinal cord and is the most vital part of the brain because it houses the respiratory and cardiovascular control centers.

Spinal cord

Cerebellum (Little brain) superior view

Second in size to the cerebrum and is located inferior to it and posterior to the medulla and pons.

Cerebellar hemispheres

There are 2 of them with a central area.

Vermis

It connects the 2 cerebellar hemispheres.

Folia (Leaves)

The cerebellar folds are slender, plated gyri that look similar to pages in a book.

Cerebellum midsagittal section

continued from a different view

Superior colliculus

Inferior colliculus

Arbor vitae (Tree living)

When cut in sagittal section, gray matter can be observed on the exterior, with deeper white matter.

Cerebellar cortex

The outer layer of gray matter.

Pons

Medulla oblongata

The Diencephalon (Two brain) sagittal section, medial view

Located in the brain's central area and has 3 main regions.

Hypothalamus (Below inner chamber)

Located below the thalamus and is a quadrangular-shaped structure.

Thalamus (Inner chamber)

Composed of paired, egg-shaped bodies centrally located in the diencephalon and makes up approximately 80% of this structure.

Pineal gland

A small endocrine gland that secretes the hormone melatonin.

Diencephalon

The Diencephalon continued

Sagittal section, magnified view

Mammillary body

Two small, round masses located just posterior to the infundibulum are relay stations for smell and taste reflexes.

Pineal gland

Thalamus

Intermediate mass of thalamus

A small bridge that connects each cerebral hemisphere that contains half of the thalamus.

Hypothalamus

Infundibulum

A stalk that connects the pituitary gland to the hypothalamus.

Pituitary gland

Looks like a large pea and is attached to the end of the infundibulum. The hypothalamus control it.

The Diencephalon continued

Frontal section view

Lateral ventricles brain

Thalamus

Third ventricles

Hypothalamus

Gray and White matter in the cerebrum

Continued frontal section view

Basal nuclei (Grey matter)

Areas of cerebral gray matter composed of paired nuclei (clusters of neuron cell bodies in the CNS) that are found deep within each cerebral hemisphere.

Cerebral cortex (Grey matter)

The superficial cerebral gray matter on the exterior of the cerebrum composed of nerve cell bodies and dendrites.

Cerebral white matter

Lies deep to the outer cortex and is composed mostly of myelinated axons that give it the white appearance.

Corpus callosum (Commissural fibers)

A prominent commissural fiber tract that is readily observable in midsagittal sections of the brain, connects the two cerebral hemispheres.

Fornix (Association fibers)

Looks like a group of commissural fibers but is actually a tract of arched association fibers.

Internal capsule (Projection fibers)

A large group of projection fibers,

contains sensory and motor tracts that connect the cerebral cortex to the brain stem and spinal cord.

External features of the Cerebrum, right lateral view with temporal lobe cut away

It is composed of 4 lobes which are mainly named for the overlying cranial bones.

Central sulcus (furrow)

Shallow groove separating frontal lobe from parietal lobe.

Postcentral gyrus (circle)

Elevation located just posterior to the central sulcus.

Parietal lobe

Occipital lobe

Transverse fissure

Deep groove separating the cerebrum from the cerebellum in the posterior/inferior part of the brain.

Precentral gyrus (circle)

Elevation located just anterior to the central sulcus.

Frontal lobe

Insula

An inner lobe that lies deep to the lateral cerebral fissure and is not visible from the exterior.

Temporal lobe

Functional areas of the Cerebral cortex, left lateral view

It is composed of 3 types of functional areas; motor, sensory, and association areas.

Broca's speech area

Located superior to the lateral sulcus and anterior to the primary motor cortex, usually in the left hemisphere; initiates impulses that result in speech. (Motor area)

Primary gustatory area

In each postcentral gyrus, just superior to the lateral sulcus; receives impulses when the taste buds are stimulated. (Sensory area)

Primary motor area

Located in the precentral gyrus of each frontal lobe; initiates impulses to skeletal muscles. (Motor area)

Central sulcus

Primary somatosensory area

Located in the postcentral gyrus of each parietal lobe; receives nerve impulses for touch, proprioception, pain, and temperature. (Sensory area, Selected Association area)

Primary visual area

In the posterior occipital lobe; receives impulses from the thalamus when the retina is stimulated. (Sensory area, Selected Association area)

Wernicke's area

Located in left temporal and parietal lobes; recognizes spoken words, translates words into thoughts, and possibly helps us sound out strange or new words. (Selected Association area)

Primary auditory area

Located in each temporal lobe across the lateral sulcus from the gustatory area; receives impulses when the auditory receptors of the ear are stimulated. (Sensory area, Selected Association area)

Cranial meninges, frontal section through skull

There are 3 that are made of connective tissue membranes; the dura mater, arachnoid mater, and pia mater.

Subarachnoid space

Between the arachnoid and pia.

Arachnoid villus (Spider-like tiny projections)

Projections of the arachnoid mater into the dural sinuses.

Falx (sickle-shaped)cerebri

The double-layered dura mater extends deep into the longitudinal fissure.

White matter

Superior sagittal sinus

Located superior to the longitudinal fissure, is one of the main dural sinuses.

Parietal bone

Dura mater (Hard mother)

The first meninx (sing) located deep to the cranial bones.

Arachnoid mater (Spider-like mother)

The 2nd meninx (sing) located deep to the dura mater.

Pia mater (Delicate mother)

The thin, inner meninx (sing). It hugs and overlays the cerebral cortex, following each gyrus and sulcus.

Cerebral cortex

Cerebral spinal fluid (CSF) circulation,frontal section of brain and spinal cord

Constantly bathes the brain and spinal cord with oxygen, nutrients, and vital chemicals.

Lateral ventricle

Located in each cerebral hemisphere with a thin membrane.

Choroid plexus (Membrane-like pleated)

Passes through ependymal cells into 4 small brain cavities or ventricles.

Cerebral aqueduct (waterway)

A thin tube that is connecting the third ventricle to the fourth ventricle.

Fourth ventricle

Located between the pons and the cerebellum.

Third ventricle

Medially located between the paired masses of the thalamus and is narrower and smaller than the other ventricle.

CSF circulation continued

Right lateral view (ventricles superimposed)

Third ventricle

Cerebral aqueduct (Waterway)

Fourth ventricle

Central canal of the spinal cord

CSF circulation continued

Sagittal section of the brain and spinal cord

Superior sagittal sinus

Arachnoid villus

Subarachnoid space

Lateral ventricle

Choroid plexus

Third ventricle