Eye
Ear
Nose
Tongue
Teeth
Bones
Skin
Hair
Nails

Eye…

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Eye is a Spherical organ hold in the hollow part of the skull.

Sclera…

Outer white part of eye is called  the sclera, also known as the white of the eye or, in older literature, as the tunica albuginea oculi, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some crucial elastic fiber.

Cornea…

The cornea is a thin layer that covers the iris, pupil and anterior chamber. A healthy cornea is completely transparent, so that it can allow light through to the pupil.

Iris…

The inside of the eye is divided into three sections called chambers. Anterior chamber: The anterior chamber is the front part of the eye between the cornea and the iris. The iris controls the amount of light that enters the eye by opening and closing the pupil. The iris uses muscles to change the size of the pupil.

The retina contains millions of light-sensitive cells (rods and cones) and other nerve cells that receive and organize visual information. Your retina sends this information to your brain through your optic nerve, enabling you to see.

Choroid…

The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissues, and lying between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm.

Lens of eyes…

Lens, in anatomy, a nearly transparent biconvex structure suspended behind the iris of the eye, the sole function of which is to focus light rays onto the retina.

Photoreceptors…

When light hits the retina (a light-sensitive layer of tissue at the back of the eye), special cells called photoreceptors turn the light into electrical signals. These electrical signals travel from the retina through the optic nerve to the brain. Then the brain turns the signals into the images you see.

f-number…

Computing the f-number of the human eye involves computing the physical aperture and focal length of the eye. The pupil can be as large as 6–7 mm wide open, which translates into the maximal physical aperture. The f-number of the human eye varies from about f/8.3 in a very brightly lit place to about f/2.1 in the dark.

If your number is between -0.25 and -2.00, you have mild nearsightedness. If your number is between -2.25 and -5.00, you have moderate nearsightedness. If your number is lower than -5.00, you have high nearsightedness.

Rods and cones…

Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones.

visual acuity…

A visual acuity of 6/6 is frequently described as meaning that a person can see detail from 6 metres (20 ft) away the same as a person with “normal” eyesight would see from 6 metres.

How do we see?

Most of the eye is filled with a clear gel called the vitreous. Light projects through your pupil and lens to the back of the eye. The inside lining of the eye is covered by special light-sensing cells that are collectively called the retina.

Ears…

Ears consist of outer ear, middle ear and inner ear.

Outer ear is pinna also called auricle. Auditory cannal. There is folds and grieves in it. The fibrous cartilaginous mussle is the muscle with which it is made of. This is elastic fiber bones. This collects all sounds and send to middle ear through auditory cannal.

Middle Ear

Diaphragm like membrane , also called ear drum separates outer ear from inner ear.

MIS: malleus incus steppus are hammer, anvil and stappas shapped oscicles.

Malleus touches ear drum. Incus articulates with malleus and stapus.

When eardrum vibrates , the malleus vibrates and incus articulates it with stappus.

Fluid in inner ear passes sounds to sound recepters in inner ear .

Inner ear. Inner ear contain 3 semi circular cannals lying perpendicular to each other.
This helps balancing function of ear. This cannal is connected to cochlea which is spiral muscle sending earing information through rescepters by means of vestigial tube to brain, sound is understood.

Eustachian tube connects inner ear to nasal cavity. Nasal air and auditory air together maintain pressure on the ear making hearing possible.

Sebasius gland makes wax protects ear from insects.

Caicum is the hollow path into auditory cannal.

Cartialegenus fluid is filled in inner ear makes earing possible.