Biology 30 Unit 4 : Ears & Eyes

Cataracts

The Lens becomes opaque

Chorid Layer

The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissue, and lying between the retina and the sclera.

Cochlea

Hair cells in this coiled structure identify sound waves and converts them to nerve impulses.

Semicircular Canals

3 cannals (Tubes) arranged at different angles which help to establish body position when you're moving , or Dynamic Equilibrium.

Dynamic Equilibrium

3 fluid filled semicircular canals with their pocket (Ampulla ) help maintain equilibrium during movement. When your head rotates , the fluid in canals moves , bending hair cells in the ampulla. They carry a nerve impulse to the brain.

Auditory Canal

Carries sound waves to the ear drum.

Sensory Neurons

Carry Info about the enviourment as electrochemical impulses from sensory receptors to the Central Nervous System.

The nose and the tongue are both for ____ reception.

Chemical

Vestibule

Connects to the MIDDLE ear via the oval window. This chamber helps to establish head position or Static Equilibrium .

When you fly in an airplane and your ears pop, it is because you are relieving pressure via the

Eustacian tube

Near-sightedness (Myopia)

Eye ball is too long + Images are focused INFRONT of the retina. (Concave lens to correct )

Thermoreceptor

Flow of heat

The area containing the highest concentration of cones is the

Fovea Centralis

The Eye

It detects the visible light portion of the electromagnetic spectrum. (EMS) The shape of the lens is changed by contractions of Cilinary Muscles on Suspensory Ligaments .

f one suffers from myopia, they have eyeballs that are too _____ and need _____ lens to correct the problem.

Long, concave

Preussre

Movement of skin or changes in the body`s surface.

Proprioreceptor

Movement of the limbs

Glaucoma

The buildup of aqueous humour which causes a pressure inside that eyes which increases.

Retina

a layer at the back of the eyeball containing cells that are sensitive to light and that trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.

Visual

changes in light intensity , movement and colour.

The most common cause of blindness in the United States is

glaucoma.

Taste receptors are called

gustatory receptors.

The senses for dynamic equilibrium are located in the

semicircular canals

Blind Spot

the point of entry of the optic nerve on the retina, insensitive to light

Ossicle

very small bones, especially one of those in the middle ear.

Eustachian Tube

Allows pressure equalization on either side of the eardrum.

Fovea Centralis

Area at centre of retina where cones are MOST DENSE and vision is at its sharpest.

From the lab, the dark layer inside the eye is the ___________ and its job is to ___________.

Choroid coat, prevent light scatter

The receptors for hearing are located in the

Cochlea

Pinna

Collects sound waves.

The cells of the eye that are most sensitive to light are the

Cones

When focusing, the lens shape changes by

Contraction of the ciliary body

Sensory Receptors

Grouped together to form sensory organs ( Eyes ears nose and tongue. ) Once a receptor becomes accustomed to a stimulus , the neuron ceases to fire , this is called Sensory adaption. olfactory cells in the nose are quick to adapt stimuli.

Equilibrium

Includes : DYNAMIC & STATIC

Middle Ear

Includes : Ear Drum & Ossicles & Eustachian Tube

Outer Ear

Includes : PINNA & Auditory canal.

Inner ear ( Fluid - Filled )

Includes : Vestibule & Semicircular Canals & Cochlea

Ossicles (3)

3 tiny bones - That carry and amplify the vibrations from the ear drum to the Oval Window on the Vestibule of the inner ear.

Static Equilibrium

The Utricle and sacule of the vestibule have small grains of calcium carbonate , otholiths , which move in response to gravity , the result of head positioning. They cause hair receptors to bend which causes a nerve impulse to brain.

Accomodation

The adjustment made by the lens and iris for near and distant objects.

Auditory Nerve

The auditory nerve is a bundle of nerve fibers that carries hearing information between the cochlea the brain.

Far-sightedness ( Hyperopia )

The eyeball is too short and images are focused BEHIND the retina (Convex lens to correct. )

Retina

The images are focused on , where photoreceptors are found. a layer at the back of the eyeball containing cells that are sensitive to light and that trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.

Lens

The lens is located in the eye. By changing its shape, the lens changes the focal distance of the eye. In other words, it focuses the light rays that pass through it (and onto the retina) in order to create clear images of objects that are positioned at various distances.

Pupil

The opening of the iris. The pupil may appear to open (dilate) and close (constrict), but it is really the iris that is the prime mover; the pupil is merely the absence of iris. The pupil determines how much light is let into the eye. Both pupils are usually of equal size.

Sensory Cells

Tiny hair (Cilia ) Cells located in the inner ear. A Mechanical stimulus ( Vibration ) causes neuron to fire.

Optic Nerve

Transfers light info to the Occipital lobe of the Cerebrum.

Ear Drum (Tympanic Membrane )

Vibrates as sound waves strike it and transfers the vibrations to the Ossicles .

The clear jellylike substance behind the lens of the eye is the

Vitreous Humour

Iris

a flat, colored, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the center.

Blood Vessel

a tubular structure carrying blood through the tissues and organs; a vein, artery, or capillary.

Semicircle canal

hree fluid-filled bony channels in the inner ear. They are situated at right angles to each other and provide information about orientation to the brain to help maintain balance.

Conjunctiva

the mucous membrane that covers the front of the eye and lines the inside of the eyelids.

Cornea

the transparent layer forming the front of the eye.

Sclera

the white outer layer of the eyeball. At the front of the eye it is continuous with the cornea.

Organ of Corti

A structure in the cochlea of the inner ear that produces nerve impulses in response to sound vibrations.

The organ of the ear that actually transfers vibrations into impulses is the

Organ of corti

Which of the following belongs to the middle ear?

Ossicles

Oval Window

Oval- shaped hole in the vestibule of the inner ear , covered by a thin layer of tissue.

Robert Boyle

in 1660 , He found that sound cannot travel in a Vacuum. Why? Does sound travel faster in air, water or a solid? Sound waves are funnelled into the Auditory Canal by your Pinna and cause the ear drum to vibrate. This vibration is carried by Middle ear ossicles (3) to the Oval window of the inner ear. As the Oval window is pushed in , the round window bellow it moves out. This causes waves in the fluid of the inner ear which bend hair cells in the cochlea . This stimulates neurons which send impulses to the brain via the Auditory Nerve. The Organ of Corti is the structure in the cochlea and Low frequences toward the tip. Hearing loss problems are caused by the destruction of hair cells . Gradually, they wear with age or exposure to loud sounds (100-300 jB) Which is twice as loud as normal talking.

Astigmatism

irregular shaped lens or Cornea

Ciliary Muscle

is a ring of smooth muscle in the eye's middle layer (vascular layer) that controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humour into Schlemm's canal.

Vitreous Humour

is the clear gel that fills the space between the lens and the retina of the eyeball of humans and other vertebrates. It is often referred to as the vitreous humour or simply "the vitreous".

Rod Cells

Photoreceptor that operate in DIM light to detect light in black and white. NO COLOUR VISION.

Cone Cells

Photoreceptors that operate in BRIGHT light to identify colour. COLOR VISION.

Smell

Presence of chemicals (Detected in olfactpry cells)

Taste

Pressure of specific chemicals (By Taste buds)

The bending of light that happens at the cornea and lens is

Refraction

The layer that contains photoreceptors is the

Retina

Balance

body movemt

The muscle responsible for the change of the shape of the lens is the

ciliary muscle.