LEC 11

Name the 5 SPECIAL SENSES.

vision

smell

taste

hearing

equilibrium (balance)

What are "unicate fits"?

People who experience imaginary odors have what are called "unicate fits."

Scientists who are trying to find a way to make neurons divide to heal nerve injuries often study the body's only mitotic neurons. These neurons are?

Olfactory receptors.

What could cause a person to be unable to easily taste sweet, sour, or salty substances?

damaged facial nerve

(Taste buds are the only part of the nervous system that can regenerate completely.)

The primary gustatory (taste) cortex is located in which lobe of the brain?

the insula (under the temporal lobe) of the brain.

Name the 3 parts of the ear and its 3 functions.

1. Outer Ear-hearing

2. Middle Ear-balance

3. Inner Ear-equilibrium

The OUTER EAR consists of 2 parts. What are they?

Pinna

External Auditory Canal

What is the PINNA made up of and what is its function?

cartilage

acts as a funnel to capture sound

Transmission of sound vibrations through the OUTER EAR occurs through what substance?

Air.

What is the middle ear normally filled with?

Air.

The middle ear is open to the nasopharynx by way of what structure and what is its function?

Auditory Tube (Eustachian Tube).

equalize the pressure between the middle ear and the outside air

SO the ear BONES can VIBRATE properly.

What 3 bones are attached to the tympanic membrane and what is their function?

1. Malleus (hammer) – vibrates the incus.

2. Incus (anvil) – vibrates the stapes.

3. Stapes (stirrup).

Together they amplify sound vibrations.

The INNER EAR is in what portion of the skull?

PET ROUS portion of the TEMPoral bone.

Bony labyrinth is filled with what fluid?

Perilymph.

What fluid is in the MEMBRANOUS LABYRINTH?

Endolymph.

What structure contains receptors for hearing?

Cochlea.

What 3 structures are responsible for balance?

1. Semicircular Canals

2. Utricle

3. Saccule.

Where are hair cells found? Hair cells are receptor cells for what 2 things?

Cochlea and semicircular canals

• hearing and equilibrium.

What cranial nerve carries information for hearing?

CN VIII (Vestibulocochlear Nerve).

What is the stapes attached to?

Oval Window.

What structure determines movement in three planes?

Semicircular Canals.

What are the two joined structures attached to the semicircular canals?

Utricle and Saccule.

What type of fluid and what receptors are within each semicircular canal?

Endolymph and hair cells.

What are calcium deposits in the inner ear called? They are an essential part of the utricle and saccule for what purpose?

Otoliths ("ear rocks"). They are essential for equilibrium.

How do otoliths stimulate the hair cells?

1. SHIFT with GRAVITY and head MOVEMENT

2. BENDS HAIR cells—tells brain what position the head is in

3. maintain EQUILIBRIUM

What is VERTIGO or LABYRINTHITIS?

semicircular canals=inflamed

• gives false sensation of motion when not moving

• can be debilitating