Understanding the Brain and Brain Structures

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AP Biology › Understanding the Brain and Brain Structures

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1

Which of the following is a not a function of the medulla oblongata?

Control speech patterns

CORRECT

Control blood pressure

0

Control breathing rate

0

Control cardiac rate

0

Control vomiting reflexes

0

Explanation

The medulla oblongata is in the lower half of the brainstem. It controls a variety of functions, mostly involuntary and essential. Heart beat, breathing, and blood pressure are controlled in the medulla oblongata, as is the vomiting reflex.

Speech is controlled by Broca's area, which is located in the frontal lobe of the cerebrum.

2

Which of the following is the best explanation for why we have a "blind spot?"

The optic nerve exits the optic disc through the blind spot

CORRECT

There are only cones in the blind spot, but no rods

0

There are both rods and cones present, but they do not contain opsins

0

None of the choices are true

0

There are only rods in the blind spot, but no cones

0

Explanation

In the blind spot, there is a lack of photoreceptors as the optic nerve exits the optic disk. We normally overcome this automatically when our brains use the information of the surrounding visual field and "fills in" the blind spot.

3

Unlike the spinal cord, the brain mainly has grey matter on the __________ and white matter on the __________.

outermost layer . . . inner layer

CORRECT

inner layer . . . outermost layer

0

left half . . . right half

0

right half . . . left half

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Explanation

Unmyelinated nervous system components make up grey matter, while myelinated axons make up white matter. The cerebral cortex on the surface of the brain contains unmyelinated neural tissue, namely the cell bodies of neurons in the central nervous system. This region is rich in connections. Below its surface lie many myelinated axon tracts to inner nuclei, the cerebellum, other areas of the cortex, and the spinal cord.

4

What is the fluid in the anterior chamber of the eye called?

Aqueous humor

CORRECT

Vitreous humor

0

Hippocratic humor

0

Galen humor

0

All of these refer to the same structure

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Explanation

The eye is divided into two chambers by the lens: the anterior and posterior chambers. The anterior chamber is filled with aqueous humor, while the posterior chamber is filled with vitreous humor. Aqueous humor nourishes the eye and maintains intraocular pressure. Aqueous humor is also important in the refraction of light, which allows humans to distinguish clear images and colors.

Hippocratic and Galen humor do not exist. Hippocrates and Galen were two ancient physicians who would use the four humors (yellow bile, black bile, phlegm, and blood) to diagnose and treat patients.

5

Please complete the following statement.

The presence of __________ in the brain indicates a modification to __________.

folds. . . surface-area-to-volume ratios

CORRECT

gray matter. . . sunlight exposure

0

white matter. . . electro-chemical gradients

0

the corpus callosum. . . circulation patterns

0

multiple lobes. . . surface-area-to-volume ratios

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Explanation

Folds are present in the human brain due to the rapid evolution of brain-related tasks while the skull shape and size remained relatively constant; therefore, folds are present as modifications to limited surface-area-to-volume ratios in the skull cavity.

6

A patient is taken to the hospital after suffering severe head trauma. He is unconscious for two days before waking up. Upon standing, the patient finds he has moderate trouble walking straight and has difficulty maintaining his balance.

Based on these symptoms, what part of the patient's brain do you suspect was damaged in the accident?

The cerebellum

CORRECT

The medulla oblongata

0

The cerebrum

0

The hypothalamus

0

The amygdala

0

Explanation

The cerebellum is mainly responsible for fine tuning the motions of the body, including balance and coordination. As a result, damage to this region would cause difficulty walking straight and maintaining balance.

7

What is the primary function of the occipital lobe?

Integrating visual input

CORRECT

Conscious thought

0

Integrating tactile input

0

Integrating auditory input

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Explanation

Each answer corresponds to one lobe of the cerebrum. The frontal lobe is responsible for conscious thought, as well as many other functions. The parietal lobe is responsible for integrating tactile information. The temporal lobe has the functions of interpreting smell and sound. The occipital lobe is associated with processing visual information.