12/11/2023 0 Comments Auditory ossicles![]() ![]() ![]() Receptor region of the cone cells is cone shaped and contain the pigment photopsin (iodopsin) which will be stimulated under intense light. Receptor region of the rod cells is rod shaped and contain the pigment rhodopsin, which will be stimulated under dim light. The capacity of the eye to change the curvature of lens depending on the distance between the eye and the object by adjusting the focal length is called the power of accommodation of the eye. The capacity of the eye to change the curvature of lens depending on the distance between the eye and the object by adjusting the focal length.ĭefine the power of accommodation of the eye.While viewing distant objects the ciliary muscles relax and the ligament stretch.While viewing near objects the ciliary muscle contracts and ligaments relax.While viewing near objects curvature of lens increases.Write your inferences in the science diary. What are the peculiarities of image formed by this type of lens? List them. ![]() Thus the amount of light falling on the lens is regulated according to the intensity of light. When the circular muscles contract in intense light, the size of the pupil decreases. When the radial muscles contract in dim light. The size of the pupil is regulated by the action of circular muscles and radial muscles. The pupil dilates in dim light and constricts in bright light. The blood and aqueous humor nourishes the tissue in eye. Vitreous humor – A jelly-like fluid filled within the vitreous chamber (between lens and retina), helps to maintain the shape of eyeball.This fluid supplies nutrients and oxygen to cornea and lens. Aqueous humor – A watery fluid seen in the aqueous chamber (between cornea and lens), oozes from the blood.Optic nerve – Transmits impulses from photoreceptors to the visual center in the brain.įluids present in the eye and their functions: It is the point of maximum visual clarity.īlindspot – The part of the retina from where the optic nerve begins. Yellow spot – The part of the retina where plenty of photoreceptors are present. The contraction and relaxation of these muscles alter the curvature of lens. Lens – Elastic transparent convex lens, connected to ciliary muscles by ligaments:Ĭiliary muscles – Circular muscles seen around the lens. Presence of melanin gives the iris a dark colour. Iris – Part of the choroid seen behind the cornea. Lysozyme, the enzyme present in tears, destroys germs that enter the eyes.Ĭonjunctiva – The layer which protects the sclera except the cornea.Īnterior part of the sclera which refracts light rays to focus on the retina. Tears : Clean and lubricate the anterior part of the eyeball. List various sense organs and the stimuli they receive.Įye socket orbit : Depressions in the skull protects the eyeball.Įxternal eye muscles : Fixes the eyeball in the orbit.Įyebrow : Protects the eye from dust and sweat.Įyelids : Protects the eye from dust and external shock.Ĭonjunctiva : Secretes mucus which pro¬tects the anterior portion of the eyeball from being dry. Receptors help sense organs in receiving various stimuli from the surroundings. Kerala State Syllabus 10th Standard Biology Solutions Chapter 2 Windows of Knowledge Windows of Knowledge Questions and Answers You can Download Windows of Knowledge Questions and Answers, Summary, Activity, Notes, Kerala Syllabus 10th Standard Biology Solutions Chapter 2 help you to revise complete Syllabus and score more marks in your examinations. ![]()
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