Chapter 17 Flashcards
What is gustation?
Taste
Gustation provides information about foods and liquids consumed.
Where are gustatory epithelial cells found?
In taste buds
Gustatory epithelial cells are also distributed on the superior surface of the tongue and portions of the pharynx and larynx.
What are lingual papillae?
Epithelial projections on the surface of the tongue
They are associated with gustatory epithelial cells.
What is the function of filiform papillae?
Provide friction to move food around the mouth
Filiform papillae do not contain taste buds.
How many taste buds do fungiform papillae contain?
About five taste buds each
Fungiform papillae are one of the types of lingual papillae.
How many taste buds can vallate papillae contain?
As many as 100 taste buds each
Vallate papillae are the largest type of lingual papillae.
What are foliate papillae?
Lingual papillae that have taste buds
They are located on the sides of the tongue.
What do taste buds contain?
Basal epithelial cells and gustatory epithelial cells
They extend microvilli (taste hairs) through the taste pore.
How long do gustatory epithelial cells survive before replacement?
About 10 days
This is a part of the natural lifecycle of taste buds.
Which cranial nerves innervate taste buds?
Cranial nerves that synapse in the solitary nucleus of the medulla oblongata
This pathway is essential for taste sensation.
Where does taste information travel after the solitary nucleus?
To the thalamus and gustatory cortex of the insula
This is part of the central processing of taste information.
Fill in the blank: Gustatory discrimination involves _______.
[key learning term]
This term refers to the ability to distinguish between different tastes.
What cranial nerves are involved in taste sensation?
Cranial nerves that synapse in the solitary nucleus of the medulla oblongata
These cranial nerves include the facial nerve (VII), glossopharyngeal nerve (IX), and vagus nerve (X)
Where does taste information travel after the solitary nucleus?
Thalamus and gustatory cortex of the insula
The insula is involved in processing taste information.
What are the four primary taste sensations?
- Sweet
- Salty
- Sour
- Bitter
These sensations are fundamental to human taste perception.
What are the two additional taste sensations beyond the primary ones?
- Umami
- Water
Umami is the savory taste associated with glutamate, while water is detected by specific receptors in the pharynx.
What is umami?
A pleasant, savory taste imparted by glutamate
It is characteristic of broths and certain cooked foods.
How does taste sensitivity vary among individuals?
Differs significantly among individuals
Many conditions related to taste sensitivity are inherited.
What is an example of inherited taste sensitivity?
Sensitivity to phenylthiocarbamide (PTC)
Some individuals can taste PTC while others cannot, showcasing genetic variation.
At what age does the number of taste receptors begin to decline rapidly?
Age 50
This decline can affect taste perception as people age.
What sense do we rely on more than any other?
Vision
Vision is the primary sense for human perception and interaction with the environment.
What are the accessory structures of the eye responsible for?
Protection, lubrication, and support
These structures enhance the functionality and health of the eye.
List the accessory structures of the eye.
- Eyelids
- Superficial epithelium of eye
- Lacrimal apparatus
These structures work together to maintain eye health.
What is the function of eyelids (palpebrae)?
To keep the surface of the eye lubricated and clean through blinking
Eyelids protect the eye from debris and help maintain moisture.
What is the palpebral fissure?
The gap that separates the free margins of the upper and lower eyelids
This gap allows for the opening and closing of the eyelids.
What connects the eyelids at the medial and lateral angles?
Medial angle (medial canthus) and lateral angle (lateral canthus)
These points are crucial for the overall structure and movement of the eyelids.
What is the role of eyelashes?
To help prevent foreign matter from reaching the eye
Eyelashes act as a barrier against dust and debris.
What do tarsal glands secrete?
A lipid-rich product
This secretion helps keep the eyelids from sticking together.
What is the lacrimal caruncle?
A mass of soft tissue at the medial angle of the eyes
It contains glands that produce secretions for eye lubrication.
What is the lacrimal caruncle?
A mass of soft tissue at the medial angle of the eye that contains glands producing thick secretions
The lacrimal caruncle is located in the inner corner of the eye and contributes to the production of eye secretions.
What is the conjunctiva?
A mucous membrane covered by an epithelium that lines the inner surface of eyelids and covers the anterior surface of the eye
The conjunctiva consists of two parts: the palpebral conjunctiva and the bulbar conjunctiva.
What does the palpebral conjunctiva cover?
The inner surface of the eyelids
This part of the conjunctiva is important for protecting the eye and maintaining moisture.
What does the bulbar conjunctiva cover?
The anterior surface of the eye
It extends to the edges of the cornea.
What is conjunctivitis?
Inflammation of the conjunctiva, commonly known as pinkeye
Conjunctivitis can be caused by infections, allergies, or irritants.
What is the function of the lacrimal apparatus?
Produces, distributes, and removes tears
It plays a crucial role in maintaining eye health and comfort.
What does the lacrimal gland do?
Produces tears that bathe conjunctival surfaces
The lacrimal gland also secretes lysozyme, an antibacterial enzyme.
What is the fornix in relation to the conjunctiva?
A pocket where the palpebral conjunctiva joins the bulbar conjunctiva
It serves as a space for the collection of tears and other secretions.
Where do tears collect in the eye?
In the lacrimal lake at the medial angle of the eye
This is the area where tears accumulate before being drained.
What are lacrimal puncta?
Pores that tears pass through
These puncta lead to the lacrimal canaliculi, which drain tears into the nasal cavity.
What are the layers of the wall of the eyeball?
- Outer fibrous layer
- Intermediate vascular layer (uvea)
- Deep inner layer (retina)
These layers provide structure and support to the eyeball.
What is the function of orbital fat in the eye?
Cushions and insulates each eye
Orbital fat helps protect the eye from trauma and provides a stable environment.
What is the structure of the eyeball?
Hollow and filled with fluid
This structure is essential for maintaining the shape of the eye.
What are the two interior cavities of the eyeball?
- Small anterior cavity (contains aqueous humor)
- Large posterior cavity (contains vitreous body)
These cavities play crucial roles in maintaining intraocular pressure and providing nutrients.
What is the fibrous layer of the eyeball also known as?
Outermost layer of the eyeball
This layer consists of the sclera and cornea.
What is the sclera?
White of the eye
The sclera provides protection and serves as an attachment for the eye muscles.
What is the cornea?
Transparent portion of the eye
The cornea is responsible for most of the eye’s optical power.
What is the corneoscleral junction?
Border between cornea and sclera
This area is also referred to as the corneal limbus.
What is the vascular layer of the eye known as?
Uvea
The uvea includes the iris, ciliary body, and choroid, and is responsible for providing blood supply to the eye.
