Anatomy ch 13

Cerebellum

Attached to the brainstem posterior to the pons. Communicates with other regions of cns through superior, middle, and inferior cerebellar peduncles

Reticular formation

A diffuse system consisting of several loosely packed nuclei scattered throughout the length of the brainstem. Functions involve cycles of activity such as sleep-wake cycle

3 categories of fibers

Association, commissural, projection

Occulomotor III

Innervates 4 of 6 muscles that move eyeball, adjusts pupil size

Inferior colliculi

Involved in hearing

Longitudinal fissure

Divides left and right hemispheres

Colliculus

Each mound of the tectum

Olfactory I and optic II

Exclusively sensory

Cerebrospinal fluid

Fills subarachnoid space

3 parts of cerebellum

Flocculonoclular lobe, vermis, 2 lateral hemispheres

Gyri

Fold on surface of hemispheres (gray matter on outer surface of cerebrum)

Pyraminds

Two prominent enlargements on the anterior surface of medulla oblongata

Olives

Two rounded oval structures protrude from the anterior surface of the medulla oblongata; nuclei involved in functions such as balance, coordination, and modulation of sound from the inner ear

Cerebral medulla

White matter of brain between cortex and nuclei; consists of tracts that connect areas of cerebral cortex to each other and other areas of cns

Arbor vitae

White matter of cerebellum

Commissural fibers

White matter that connects left and right hemispheres

Tectum

(Roof) consists of 4 nuclei that form mounds on the dorsal surface

Thalamus

Cluster of nuclei; has 2 large, lateral portions connected in the center by a small stalk called the interthalamic adhesion (intermediate mass), influences mood and actions associated with strong emotions

Neural plate

Cns develops from thsi

Meninges

Connective tissue membranes that surround and protect the brain and spinal cord

Tegmentum

Consists of ascending tracts which carry sensory information from the spinal cord to the brain

Cerebral peduncles

Constitute the portion of the midbrain ventral to the tegmentum

Facial VII

Controls all muscles of facial expression

Trigeminal V

Greatest sensory function

Sulci

Grooves between gyri

Basal nuclei

Group of functionally related nuclei located bilaterally in the inferior cerebrum, diencephalon, and midbrain; involved in control of motor functions

Brainstem

Medulla oblongata, pons, midbrain; connects spinal cord to remainder of brain; responsible for many essential functions; damage is fatal

Medulla oblongata

Most inferior part of brain stem, contains sensory and motor tracts, part of reticular formation

Hypothalamus

Most inferior; mammillary bodies appear as bulges on the ventral surface; involved in olfactory reflexes and emotional responses to odor; eating disorder, intense thirst, varying body temps are dysfunction of this

Dura mater

Most superficial meningeal layer

Decussate

Nerve fibers that cross from one side of the nervous system to the other

Pons

Part of brain stem just superior to the medulla oblongata; connects the medulla to the midbrain; contains ascending and descending tracts; relays info from the cerebrum to the cerebellum; involved in controlling respiration along with the medulla oblongata

Diencephalon

Part of the brain located between the brainstem and the cerebrum; consists of the thalamus, subthalamus, epithalamus, hypothalamus

Limbic system

Parts of cerebrum and diencephalon; plays central role in survival functions and emotional interpretation of sensory input

Dropping of upper eyelid

Ptosis, damage to occulomotor

Superior colliculi

Receive input from the eyes, skin, cerebrum, and inferior colliculi. Involved in visual reflexes which control the movement of the head, eyes, and body toward a visual, auditory, or tactile stimuli

Cranial nerves organized by

Roman numerals from anterior to posterior

Central sulcus

Separates frontal and parietal lobes

Lateral fissure

Separates temporal lobe from rest of cerebrum

Subthalamus

Small area inferior to thalamus that contains several ascending and descending tracts and the subthalamic nuclei, involved in controlling motor functions

Epithalamus

Small area superior and posterior to thalamus, consists of habenular nuclei and the pineal body (onset of puberty)

Midbrain or mesencephalon

Smallest region of brain stem; located just superior to the pons and contains the nuclei of cranial nerves

Lateral cerebellar peduncles

Smooth flowing movements, fine motor coordination

Infundibulum

Stalk that extends from floor of hypothalamus and connects it to the posterior pituitary gland (hypophysis)

Glossopharyngeal

Taste