16 Questions
What type of sense organ is the tongue?
Gustatoreceptors
The eyes are attached to the skull using 4 muscles.
False
What is the function of the lacrimal glands?
To produce tears that wash away dust particles, clean the surface of eyes, lubricate the surface of eyes, and kill bacteria.
The sclerotic layer of the eyeball is made up of tough, non-elastic, _______________________ tissue.
fibrous
What is the function of the eyebrows?
To protect the eyes from dust and sweat
Match the following sense organs with their corresponding functions:
Photoreceptors = Sense Organs of Sight Mechanoreceptors = Sense Organs of Touch Gustatoreceptors = Sense Organs of Taste Olfactory receptors = Sense Organs of Smell
The cornea is a part of the sclerotic layer.
True
What is the function of the nasolacrimal duct?
To conduct the secretion or water of the eye into the nasal cavity.
What is the function of the cornea?
Refracts light and helps in focusing
The cornea can be replaced by a healthy cornea from a donated eye.
True
What is the function of the conjunctiva?
Protects the surface of the eye
The choroid layer contains the pigment ___________________ which helps in absorption of light.
melanin
Match the following eye structures with their functions:
Cornea = Refracts light and helps in focusing Conjunctiva = Protects the surface of the eye Choroid = Absorbs light and prevents total internal reflection Iris = Regulates the amount of light entering the eye
The ciliary body is connected to the lens by suspensory ligament.
True
What is the function of the pupil?
Allows light to enter the eye
What is the function of the radial muscles in the iris?
Widen the pupil
Study Notes
Types of Sense Organs
- There are five types of sense organs: photoreceptors (sight), photoreceptors combined with statoreceptors (hearing-cum-equilibrium), mechanoreceptors (touch), gustatoreceptors (taste), and olfactory receptors (smell)
The Eyes
- The eyes are attached to the eye orbits of the skull and can rotate with the help of six muscles
- The eyes are protected by:
- Adipose tissue (cushion-like, protects from mechanical injury and shock)
- Eyelids (protect from injury, clean the eyeball, close during night and bright light, spread lubricating secretions)
- Eyelashes (prevent dust and foreign particles from entering the eye)
- Eyebrows (protect from rain, dust, and sweat)
- Lacrimal glands (produce tears, wash away dust, clean and lubricate the eyes, kill bacteria)
- The structure of the eyeball consists of three layers:
Sclerotic Layer (Sclera)
- Made up of tough, non-elastic, fibrous tissue
- White in color
- Surrounds the entire eyeball
- Function: Provides and maintains the shape of the eyeball
- Cornea: a transparent, visible part of the sclera; refracts light and helps in focusing
- Cornea facts:
- Derives oxygen by diffusion
- Can become opaque and non-functional
- Remains alive up to 40 hours after death
Conjunctiva
- A thin membrane covering the entire front part of the eye
- Continuous with the inner lining of eyelids
- Over the cornea, it is reduced to a single layer of transparent epithelium
- Function: Protects the surface of the eye
- Viral infection causes conjunctivitis (reddening of the eyes)
Choroid Layer
- Supplied with blood vessels to provide nourishment to the eye
- Dark black in color
- Contains melanin
- Functions:
- Absorbs light
- Prevents total internal reflection, causing blurring of image
- Blood vessels nourish the inner layer of the retina
- Ciliary body: an extension of the choroid layer; secretes aqueous humor and helps in accommodation
- Iris: an extension of the ciliary body, partially covering the eye and leaving an opening called the pupil
- Iris functions:
- Regulates the amount of light entering the eye by widening and constricting the pupil
- The blue, black, or brown color of the eye is the color of the iris
- Pupil: light enters the eye through the pupil
Learn about the different types of sense organs, including photoreceptors, mechanoreceptors, gustatoreceptors, and olfactory receptors, with a focus on the eyes and ears.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
