Blood Brain Barrier (BBB), Basal Nuclei, + Cerebellum

Exam 1 - A&P 142

What is the blood-brain barrier (BBB)

A protective barrier between the blood and brain tissue that controls what substances can enter the brain.

What is the main function of the BBB

It protects the brain from harmful substances and helps maintain a stable environment for neurons.

Why is the BBB physiologically important

Neurons need a very controlled environment to function properly.

What makes up the BBB

Mainly tightly connected cells lining brain capillaries, which limit what can pass from the blood into brain tissue.

Where is the BBB absent or weak

It is absent or reduced in certain areas called circumventricular organs.

Why is the BBB absent in these areas

These areas need to monitor or release substances into the bloodstream, such as hormones, or detect changes in the blood.

What is an important example of a brain area without a typical BBB

The hypothalamus has areas where the BBB is reduced, allowing it to monitor the blood.

What is the main function of the medulla oblongata

It controls important automatic functions such as breathing, heart rate, blood pressure, swallowing, coughing, and vomiting.

What is the main function of the pons

It helps regulate breathing and acts as a communication bridge between different parts of the brain.

What are the superior colliculi responsible for

Visual reflexes, especially orienting the eyes and head toward visual stimuli.

What are the inferior colliculi responsible for

Auditory reflexes, especially orienting the head toward sounds.

Are the functions of the superior and inferior colliculi conscious or subconscious

Subconscious (reflexive).

What are the basal nuclei

Groups of gray matter located deep within the cerebral hemispheres.

Where are the basal nuclei found

Deep within the cerebrum, beneath the cerebral cortex.

What is the main function of the basal nuclei

They help control and coordinate voluntary movements.

What else do the basal nuclei help regulate

Muscle tone, posture, and the initiation and stopping of movements.

Are the basal nuclei responsible for conscious movement

They help regulate movement, but their control is largely subconscious.

What is the cerebellum responsible for

Coordination of movement, balance, posture, and maintaining muscle tone.

Where is the cerebellum located

At the back of the brain, behind the brainstem.

What are the main anatomical structures of the cerebellum

The cerebellar hemispheres and the vermis.

What is the vermis

The narrow central region connecting the two cerebellar hemispheres.

What are cerebellar peduncles

Nerve fiber bundles that connect the cerebellum to the brainstem.

What happens when the cerebellum is damaged

Problems with balance, coordination, posture, and smooth movements.

What are some disorders associated with cerebellar damage

Ataxia, tremors, and difficulty coordinating movements.

What is ataxia

A loss of coordination or balance caused by problems with the cerebellum or its connections.

What is the pineal gland

A small endocrine gland located in the epithalamus of the diencephalon.

What does the pineal gland produce

Melatonin.

What is the function of melatonin

It helps regulate the sleep-wake cycle.