Lecture 22 Ears, Nose, Mouth

What is the highlighted part of the nose?

Olfactory epithelium

What is the highlighted part of the nose?

Olfactory tract 

What is the highlighted part of the nose?

Olfactory bulb

What is the highlighted part of the nose?

Nasal conchae 

What is the highlighted part of the nose?

Route of inhaled air 

What is the function of the nose?

• Respiration

• Filtration

• Sense of smell

• Speech production

• Protection

• Taste enhancement

How is smell received and sensed?

• The axons of olfactory sensory neurons form the olfactory nerve (CN I).

• They pass through the ethmoid bone and synapse in the glomeruli of the olfactory bulb.

• The axons of mitral cells (the output cells of the olfactory bulb) form the olfactory tract.

What is the highlighted part of the mouth?

Epiglottis

What is the highlighted part of the mouth?

Palatine tonsil 

What is the highlighted part of the mouth?

Lingual tonsil

What is the highlighted part of the mouth?

Fungiform papillae

What is the highlighted part of the mouth?

Vallate papillae

What is the highlighted part of the mouth?

Foliate papillae

What is the function of the mouth?

• Digestion

• Respiration 

• Speech

• Sensory perception

• Protection

How is taste received and sensed?

• Binding of Taste stimuli- different taste modalities are detected when taste stimuli interacts with specific taste receptors on the taste receptor cell

• Activation of G-protein complex receptors- when activated they trigger intracellular signaling pathways 

• Release of Neurotransmitters- The activation of taste receptors leads to the releases of neurotransmitter which stimulate nearby sensory nerve fibers

What are the three major areas of the ears?

• External ear

• Middle ear

• Internal ear

What are the different parts of the external ear?

• Auricle (pinna)

• External acoustic meatus

• Tympanic membrane (ear drum)

• Meatus

What are the different parts of the middle ear?

• Malleus

• Incus

• Stapes

What are the different parts of the internal ear?

• Cochlea

• Cochlear nerve

• Vestibular nerve

Explain how the parts of the ear function to transmit sound (15.9)

• External Ear

  • Eardrum- Vibrates in response to sound which. Send the sounds into the inner ear

• Middle ear

  • Ossicles- amplify the vibrations and help transmit them to the cochlea

  • Eustachian Tube- equalizes air pressure on either side of the eardrum during swallowing or yawning. It prevents pressure related pain during rapid changes in pressure 

• Inner Ear 

  • Cochlea- Converts sound vibration into electrical signals for the brain to interpret as sound. This allows us to hear the world around us