Anatomy of the Brain and Ear

Practice flashcards based on anatomy and physiology concepts covered in the lecture notes.

What structures control motor activity apart from the cortex?

The cerebellum, basal nuclei, thalamus, and red nucleus.

What is the main function of the cerebellum?

The cerebellum compares intended motor actions from the cerebral cortex with actual muscle movements and provides feedback.

What does the term 'extra-pyramidal' pathways refer to?

It refers to components of the motor control systems that are not part of the pyramidal tracts, including the basal ganglia and cerebellar pathways.

What are the three parts of the brainstem?

Midbrain, pons, and medulla oblongata.

How is the cerebellum connected to the brainstem?

By three peduncles: superior, middle, and inferior peduncles.

What role do the basal ganglia play in motor activity?

They process cortical impulses and can inhibit certain motor activities.

What is the location and function of the olives in the medulla oblongata?

Olives are swellings on either side of the pyramids, housing the inferior olivary nucleus which sends signals to the cerebellum.

What cranial nerves are primarily affected by increased intracranial pressure?

Oculomotor (III) and abducens (VI) nerves.

Describe the Romberg test.

A test for position sense where a patient stands with feet together and arms outstretched to assess balance with eyes open and closed.

What is hydrocephalus?

An increase in cerebrospinal fluid volume within the ventricular system due to overproduction, obstruction to flow, or impaired absorption.

What is the structure and function of the iris?

The iris is composed of two layers controlling pupil size and its color is determined by pigmentation and vascularity.

What are the main connections of the vestibular nuclei?

Efferents connect to the cerebellum, spinal cord, and cranial nerve nuclei III, IV, and VI.

Explain what the superior and inferior colliculi do.

Superior colliculi are involved in visual reflexes, while inferior colliculi are involved in auditory reflexes.

What defines cerebellar ataxia?

Impaired coordination of movement due to lesions in the cerebellum, characterized by a wide-based gait and poor balance.

What is the main sensory nucleus in the brainstem?

The nucleus of the trigeminal nerve, responsible for processing general sensory information.

What is the role of the ciliary muscle in accommodation?

It contracts to make the lens thicker for near vision and relaxes for distance vision.