A&P I Lecture Chapter 12 HW

How many major regions are contained within the diencephalon?

3 The diencephalon consists of 3 regions, the thalamus, the epithalamus, and the hypothalamus.

How many regions make up the brain stem?

3 regions The brain stem consists of the midbrain, pons, and medulla oblongata.

What characteristic does a spinocerebellar tract neuron share with a sensory neuron originating in the quadriceps femoris?

Both neurons carry afferent information.

Where is the arbor vitae located?

Cerebellum The white matter in the cerebellum has a branching arrangement that resembles a tree. This structure is named for its appearance. The term arbor vitae means "tree of life."

Which passageway connects the third and fourth ventricles?

Cerebral aqueduct The cerebral aqueduct is the narrow passageway that connects the third and fourth ventricles. It can sometimes be observed on a midsagittal section.

Which region of the brain is necessary for consciousness?

Cerebrum Correct. The cerebrum is involved in higher order functions such as consciousness, personality, and intellect.

What structure connects the right and left cerebral hemispheres?

Corpus callosum The corpus callosum is a large fiber tract of axons connecting the right cerebral hemisphere to the left cerebral hemisphere.

Which region of the diencephalon contains the pineal body?

Epithalamus The epithalamus is a region posterior to the thalamus that contains the pineal body.

The pineal body secretes melanocyte stimulating hormone (MSH).

False The pineal body secretes the hormone melatonin which is secreted when light is not entering the eyes (typically at night).

The brain is a solid organ that lacks cavities.

False The brain is not completely solid; it contains cavities called ventricles.

The cerebellum is present on the ventral surface of the sheep brain.

False The cerebellum is not a ventral structure. It is located on the dorsal surface of the brain.

Which ventricle is located within the brain stem?

Fourth ventricle The fourth ventricle is located anterior to the cerebellum. It is continuous with the third ventricle through the cerebral aqueduct at its superior border and continuous with the central canal at its inferior border.

Which part of the diencephalon is connected to the pituitary gland?

Hypothalamus The hypothalamus is connected to the pituitary gland by the infundibulum.

Which of the following structures attach the pituitary gland to the brain?

Infundibulum The infundibulum attaches the pituitary gland to the hypothalamus. It contains axons that originate in the hypothalamus and end in the posterior pituitary.

Which of the following ventricles is found under the corpus callosum?

Lateral ventricles

Which ventricles are divided by the septum pellucidum?

Lateral ventricles The lateral ventricles are cavities within the cerebrum. The right and left lateral ventricles are separated on midline by the septum pellucidum.

Which region contains the corpora quadrigemina?

Midbrain The corpora quadrigemina are found on the posterior surface of the midbrain. They can be observed by looking into the transverse fissure.

Identify cranial nerve I.

Olfactory nerve

Which of the following areas takes visual information from one side of the body and conveys it to the opposite side?

Optic chiasm The optic chiasm is where the optic nerves cross midline, so that sensory information from one side of the body is processed on the opposite side of the brain.

Which of the following structures is not part of the central nervous system?

Optic nerve Nerves are bundles of axons found in the peripheral nervous system. The optic nerve is an extension of the brain, not part of the brain.

Which of the following glands can be observed on the ventral surface of the sheep brain?

Pituitary gland The pituitary gland can be seen on the ventral surface of the brain. It can easily be removed with the meninges if care isn't taken to keep it attached.

ependymal cell

Specialized ependymal cells participate in the filtration, absorption, and secretory processes that create cerebrospinal fluid.

What part of the corpora quadrigemina is clearly observed in a midsagittal section?

Superior colliculus The superior colliculus is clearly observed in the transverse fissure on the back of the midbrain. It is involved with directing eye movement.

Which region acts as a relay center for sensory messages ascending to the cerebrum?

Thalamus The thalamus acts as a filter, sending the most important sensory messages on to the correct location in the cerebrum.

Which of the following areas form the central core of the brain?

Thalamus The thalamus is the central region of the diencephalon and forms the central core of the brain. The thalamus is enclosed by the cerebrum.

What is the function of white matter?

Transmits messages White matter is predominately myelinated axons, which transmit information (action potentials).

The foramen magnum marks the border between the medulla oblongata and spinal cord.

True The medulla oblongata is the lowest region of the brain stem. It is continuous with the spinal cord at the foramen magnum of the skull.

All three regions of the brain stem can be observed on the ventral surface of the brain.

True All 3 regions of the brain stem, the midbrain, pons, and medulla oblongata, can be observed on the ventral surface.

The composition of gray matter includes neuron cell bodies.

True Gray matter consists of neuron cell bodies, unmyelinated axons, and neuroglial cells.

Cerebrospinal fluid is produced within the ventricles.

True The choroid plexus produces cerebrospinal fluid. It is found in each of the ventricles.

The inferior colliculi are part of the corpora quadrigemina.

True The corpora quadrigemina is a collection of 4 bumps on the posterior surface of the midbrain. It is composed of the 2 superior colliculi and the 2 inferior colliculi.

White matter has a fatty consistency.

True White matter consists mainly of myelinated axons. Myelination is created by the membrane of a neuroglial cell wrapping many times tightly around an axon. Recall the plasma membrane is a lipid bilayer, therefore white matter contains a lot of fat. The high amount of fat gives white matter it's characteristic glossy white appearance.

The ventricles are all interconnected.

Ture Narrow passageways connect the ventricles together, so that cerebrospinal fluid flows freely inside the ventricular system.

Identify the passageway found in the spinal cord that is continuous with the ventricles.

central canal The central canal is the canal found in the spinal cord that originates off of the fourth ventricle.

The diencephalon is found in between the brain stem and the cerebrum.

diencephalon The diencephalon forms the core of the brain, housed between the cerebrum and brainstem.

What type of tissue makes up the cerebral cortex?

gray matter The cerebral cortex is composed of gray matter. Gray matter is primarily neuron cell bodies.

Part complete Which area of the brain stem is in contact with the spinal cord?

medula oblongada The medulla oblongata is the lowest region of the brain stem. It is continuous with the spinal cord at the foramen magnum of the skull.

During meningitis, which of the following is the most likely to be a direct source of pathogens that may spread to the brain?

pia mater The pia mater is meningeal layer closest to the brain.