Chapter 17 - Lab

Forms pathways between the diencephalon, cerebrum, and cerebellum

What is the function of the brain Stem?

Midbrain

The superior portion of the brain stem, mainly composed of tracts of myelinated axons.

Tectum

The dorsal surface of the midbrain.

Corpora quadrigemina

Four lumps on the tectum of the midbrain.

Superior colliculi

The two superior lumps on the tectum that house reflex centers for head and eye movement.

Inferior colliculi

The two inferior lumps on the tectum that house reflex centers responding to startling sounds.

Pons

The central portion of the brain stem.

Nuclei

Clusters of neuron bodies involved in maintaining the rhythm of breathing.

Medulla Oblongata

The most inferior part of the brain stem, connected directly to the spinal cord, controlling heartbeat and breathing.

Cerebral aqueduct

The canal that passes through the midbrain, connecting the third and fourth ventricles.

Cerebrospinal fluid

What flows through the cerebral aqueduct?

Pineal Gland

produces melatonin, a hormone involvedin sleep cycles

Fourth ventricle

Receives CSF from the 3rd ventricle (via the cerebral aqueduct) and allows it to move inferiorly into the central canal of the spinal cord as well as laterally and posteriorly into the subarachnoid space.

It exerts control over heart rate and breathing

A blow to the back of the head that damages the medulla oblongata may be fatal. Why?

Cerebellum

Region of the brain that unconsciously coordinates movements of the body.

Transverse fissure

A deep groove that separates the cerebellum from the cerebrum.

Vermis

The midsection of the cerebellum

Cerebellar Hemisphere

The sides of the cerebellum

Folia

Folds on the surface of each cerebellar hemisphere, separated by shallow sulci.

Arbor Vitae

Branches of white matter in the cerebellum resembling a tree.

Nerve

bundle of axons located outside of the CNS

12 pairs

How many nerves are attached directly to the brain?

Cranial nerves

Nerves that carry sensory information to and from the brain, with 12 pairs attached directly to it.

The olfactory and the optic nerves

Which two nerves attach to the brain stem?

Olfactory nerve

Cranial nerve that provides the sense of smell.

Optic nerve

Cranial nerve that provides vision.

Oculomotor nerve

Cranial nerve responsible for opening and moving the eyes and adjusting pupil width.

Trochlear Nerve

Looking down and moving eyes towards or away from nose

Trigeminal Nerve

Carries sensory information from face and motor commands to chewing muscles

Abducens nerve

moving eyes left and right

Facial nerve

controls facial muscles to make facial expression and provide sense of taste

Vestibulocochlear nerve

provides sense of hearing

Glossopharyngeal nerve

taste sensations, control muscles for swallowing, bp regulation, saliva production

Vagus nerve

regulates automatic bodily processes

Accessory nerve

controls shoulder and neck movement

Hypoglossal nerve

controls tongue movement

carry commands from the brain to motor neurons in the spinal cord. Ascending tracts through the dorsal portion carry sensory information to the brain. Contains nuclei associated with exerting control over the heartbeat, and nuclei that work with the pons to control breathing.

What function does the Medulla Oblongata serve?

Causes problems moving the eyeballs.

What would happen if cranial nerve damage occurs to the oculomotor nerve?

Problem with vision

What problem would a person have if his optic nerves were damaged?

Vagus nerves

Which pair of cranial nerves innervates various structures in the ventral body cavity?

The heart, lungs, and stomach

What parts of the body do vagus nerves connect to the brain?

Olfactory nerves

extend from the nasal cavity to the anterior portion of the brain

Olfactory bulbs

carries sensory information about smell

Olfactory tract

carry sensory information about smell

Optic nerves

carries visual sensory information

Optic chiasm

The pair of optic nerves

Optic tracts

Where axons travel through the brain paired together after the optic chiasm.

Oculomotor nerves

between the mammillary bodies and the pons, carry motor commands for movement of the eyeballs

Trigeminal nerves

extend from the sides of pons, receive sensory information from parts of the face, mouth, and tongue, and send motor commands to muscles involved in chewing.

A tract is found in the CNS, while a nerve is found in the PNS.

What is the main difference between a tract and a nerve?

Regulates automatic bodily processes such as heart rate and digestion.

What is the function of the Vagus nerve?

There are multiple olfactory nerves attached to each side of the brain. The other cranial nerves are paired.

How does the structure of olfactory nerves differ from the other cranial nerves?