AP 2 2.1: The Brain (part 2)

Question 1

diencephalon

Answer 1

The hypothalamus, thalamus, and epithalamus are collectively in a portion of the brain known as the diencephalon.

Question 2

hypothalamus

Answer 2

The hypothalamus, forming the floor of the third ventricle, maintains homeostasis, or the constancy of the internal environment.

The hypothalamus also contains centers for regulating basic body functions, such as hunger, sleep, thirst, body temperature, water balance, and blood pressure. The hypothalamus controls the pituitary gland

Question 3

endocrine system

Answer 3

The hypothalamus controls the pituitary gland which regulates body hormones of the endocrine system, which controls the body’s hormonal production. The hypothalamus serves as a link between the nervous and endocrine systems.

Question 4

thalamus

Answer 4

The thalamus, in the roof of the third ventricle, is the last portion of the brain for sensory input before the cerebrum . It serves as a central relay station for sensory impulses traveling upward from other parts of the body and the brain to the cerebrum. The thalamus receives all sensory impulses (except those associated with the sense of smell), filters out unimportant sensory information, and directs it to the appropriate regions of the cerebrum for interpretation.

Question 5

epithalamus

Answer 5

The epithalamus forms the roof of the third ventricle and is mostly composed of the pineal gland

Question 6

pineal gland

Answer 6

The epithalamus (Figure 2.10) forms the roof of the third ventricle and is mostly composed of the pineal gland . The pineal gland which secretes melatonin, a hormone that controls the wake-sleep cycle.

Question 7

cerebellum

Answer 7

The cerebellum, located inferiorly and posteriorly to the brain, is convoluted and divided into two hemispheres with deep fissures subdividing it into three lobes. Because of its appearance, it is often called the “mini-brain.” The cerebellum has the gray matter and white matter reversed from the spinal cord. It is composed of a thin outer cortex of gray matter and internal white matter. The cerebellum works to coordinate body movements by relaying information to the cerebral motor cortex. The cerebellum is also involved with maintaining balance, controlling certain eye movements, maintaining normal muscle tone, and maintaining posture. Muscle tone is the degree at which muscles remain partially contracted while at rest. **Muscle tone **is continuously monitored and maintained by the cerebellum to keep bones and joints in place.

Question 8

anterior lobes and posterior lobes of the cerebellum

Answer 8

The anterior lobes and posterior lobes of the cerebellum (Figure 2.12) receive information from the body trunk and influence the motor activities of the trunk, shoulder, and pectoral girdle muscles.

Question 8

vermis

cerebellum

Answer 8

The intermediate portion, called the vermis, coordinates limb movements (

Question 9

cerebellar peduncles and flocculonodular lobes

cerebellum

Answer 9

The cerebellar peduncles and flocculonodular lobes are located on the anterior portion of the cerebellum. The cerebellar peduncles serve to connect the cerebellum to the other parts of the brain

Question 10

limbic system

Answer 10

he limbic system involves portions of both the unconscious and conscious brain. It lies just beneath the cerebral cortex and contains neural pathways that connect portions of the frontal lobes, temporal lobes, thalamus, and hypothalamus.

The limbic system is our feeling brain because stimulation of different areas of the limbic system causes rage, pain, pleasure, or sorrow. The limbic system affects the emotional aspects of behavior outcomes as well as how people evaluate rewards and consequences. The limbic system is also involved in the processes of learning and memory.

Question 11

cingulate gyrus

limbic system

Answer 11

The cingulate gyrus, also known as the limbic lobe, is located deep to the cerebrum. The cingulate gyrus serves to connect the different lobes of the cerebrum.

Question 12

hippocampus

limbic system

Answer 12

The hippocampus is involved in the retrieval and storage of memories.

Question 13

amygdala

limbic system

Answer 13

The amygdala is a small portion of the limbic system that is involved in emotions such as rage and anger.

Question 14

fornix

limbic system

Answer 14

The fornix is a bundle of nerve fibers that serves as a connection to the hippocampus

Question 15

mamillary bodies

limbic system

Answer 15

The mamillary bodies (Figure 2.15) contain fibers that project into the thalamus and assist with the memory of smell.

Question 16

short-term memory

limbic system

Answer 16

he limbic system is essential to both short-term and long-term memory. An example of short-term memory in humans is the ability to recall a seven-digit telephone number long enough to dial the number.

Question 17

long-term memory

limbic system

Answer 17

An example of long-term memory is the ability to recall the events of the day. Memories are not stored in one specific area within the brain but instead are stored throughout the cerebral hemispheres. The hippocampus acts as a memory center to help with memory storage and retrieval. The involvement of the limbic system explains why emotionally charged events result in our most vivid memories. The fact that the limbic system communicates with the all the sensory areas accounts for the ability of a sensory stimulus to awaken a complex memory.

Question 18

basal nuclei

Answer 18

The basal nuclei (also known as basal ganglia) are masses of gray matter that lie deep within each hemisphere of the cerebrum (Figure 2.16). The basal ganglia are also part of the limbic system. The basal ganglia are responsible for working with the cerebellum to regulate planning motor movements and motor learning.

Question 19

putamen, caudate nucleus, and Globus pallidus (medial and lateral)

basal nuclei

Answer 19

The putamen, caudate nucleus, and Globus pallidus (medial and lateral) are all parts of the basal ganglia. In general, the overall effect of the basal ganglia is to have an inhibitory effect on the cerebral cortex, or to slow and control precise movements. Parkinson’s disease is a disorder of the basal ganglia.

Question 20

Apraxia

basal nuclei

Answer 20

Apraxia, or difficulty with motor planning, is a symptom of Parkinson’s disease. Apraxia results in rigid movements and difficulty executing a motor plan.