chapter 14 questions a+p

How would decreased diffusion across the arachnoid granulations affect the volume of cerebrospinal fluid in the ventricles?

If diffusion across the arachnoid granulations decreased, less CSF would reenter the bloodstream, and CSF would accumulate in the ventricles. The increased pressure within the ventricles due to accumulated CSF could damage the brain.

The medulla oblongata is one of the smallest sections of the brain, yet damage there can cause death, whereas similar damage in the cerebrum might go unnoticed. Why?

Damage to the medulla oblongata can be lethal because it contains many vital autonomic reflex centers, including those that control breathing and regulate heart rate and force of contraction, which affect blood pressure.

If the respiratory centers of the pons were damaged, what respiratory controls might be lost?

Damage to the respiratory centers of the pons could result in loss of ability to modify the respiratory rhythmicity centers of the medulla oblongata, which set the basic pace for respiratory movements.

What would happen if the normal circulation or resorption of CSF were blocked?

If the normal circulation or resorption of cerebrospinal fluid (CSF) became blocked, CSF would continue to be produced at the choroid plexus in each ventricle, but the fluid would remain there, causing the ventricles to swell—a condition known as hydrocephalus.

Many water-soluble molecules that are abundant in the blood occur in small amounts or not at all in the cerebrospinal fluid (CSF) of the brain. Why?

Many watersoluble molecules are rare or absent in the extracellular (ECF), or cerebrospinal fluid (CSF), of the brain because the blood brain barrier regulates the movement of such molecules from the blood to the ECF of the brain.

What brain regions make up the brainstem?

The brainstem is made up of the midbrain, pons, and medulla oblongata.

Name the four major regions of the brain.

The four major regions of the brain are the cerebrum, cerebellum, diencephalon, and brainstem.

Identify the components of the medulla oblongata that are responsible for relaying somatic sensory information to the thalamus.

The gracile nucleus and cuneate nucleus are responsible for relaying somatic sensory information to the thalamus.

From superficial to deep, name the layers that make up the cranial meninges.

The layers of the cranial meninges are the outer dura mater, the middle arachnoid mater, and the inner pia mater.

List the maters surrounding the brain from the deepest layer to the most superficial layer.

The maters surrounding the brain (from deepest to most superficial) are the pia mater, the arachnoid mater, and the dura mater (meningeal cranial dura and periosteal cranial dura).

Name the four groups of components found in the pons.

The pons contains (1) sensory and motor nuclei of cranial nerves (V, VI, VII, and VIII), (2) nuclei involved with the control of respiration, (3) nuclei and tracts that process and relay information sent to or from the cerebellum, and (4) ascending, descending, and transverse pontine fibers.

Which primary brain vesicle is destined to form the cerebellum, pons, and medulla oblongata?

The rhombencephalon or hindbrain develops into the cerebellum, pons, and medulla oblongata.