Chapter 14

Question 1

Sense Organs

Answer 1

Sense organs are the specialized organs composed of sensory neurons, which help us to perceive and respond to our surroundings. There are five sense organs – eyes, ears, nose, tongue, and skin.

Question 2

Sensory receptors

Answer 2

Sensory receptors are specialized cells that convert external information into electrochemical energy (nerve impulses) then relay it to the C.N.S. Each one can only respond to one kind of stimulus and when grouped together they result in only one type of sensation (sight, sound, taste,etc)

Question 3

Dendrites

Answer 3

a short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.

Question 4

Sensory Adaptation

Answer 4

Occurs when you have adjusted to a change in the environment, and neurons cease to fire even though stimulus is still present (lingering scent, fabric on your skin, etc)

Question 5

Types of receptors

Answer 5

Photoreceptors (Eyes), Chemoreceptors (taste buds, nose, carotid arteries & brain (blood ph)), Mechanoreceptors (Ears, propriocepters and touch) & Thermoreceptors (temperature)

Question 6

How is sensory reception converted into perception

Answer 6

Sensory receptors > nerve impulse > sensation (when impulse reaches cerebrum) > perception

Question 7

Olfactory cells

Answer 7

Olfactory cells, also known as olfactory sensory neurons or olfactory receptors, are nerve cells that detect and process odors. They are located in the upper part of the nasal cavity.

Question 8

How do you smell

Answer 8

Airborne chemicals combine with receptor ends on olfactory cells to carry impulses to the temporal lobe of the brain which process the information

Question 9

The 3 layers of the eye

Answer 9

Sclera, Choroid Layer & Retina

Question 10

Sclera

Answer 10

The white fibrous outermost protective layer of eye that maintains the eye shape.

Question 11

Cornea

Answer 11

The cornea is the clear, dome-shaped layer on the front of the eye that controls how light enters the eye. It requires O2 and nutrients absorbed from gasses dissolved in tears

Question 12

Choroid Layer

Answer 12

The choroid is a thin layer of tissue in the eye that contains blood vessels and supplies oxygen and nutrients to the retina.

Question 13

Ciliary muscles

Answer 13

The ciliary muscle is a multi-unit smooth muscle in the eye responsible for adjusting the shape of the lens to enable focusing on objects at different distances, by contracting and relaxing

Question 14

Aqueous humor

Answer 14

the clear fluid filling the space in the front of the eyeball between the lens and the cornea.

Question 15

Suspensory ligaments

Answer 15

The suspensory ligament of the eye is a ring-shaped band of tissue that holds the lens of the eye in place. It’s made up of a series of fibers that connect the ciliary body to the lens capsule.

Question 16

Vitreous humor

Answer 16

The vitreous humor is a gel-like substance that fills the space between the retina and the lens of the eye. It’s made up of mostly water and collagen, and helps maintain the eye’s shape and nourish it

Question 17

3 layers of cells in the Retina

Answer 17

Light-sensitive cells, bipolar cells and cells from optic nerve

Question 18

Retina

Answer 18

The light-sensitive layers of nerve tissue at the back of the eye that receive images and sends them as electric signals through the optic nerve to the brain.

Question 19

What are Rods & Cones

Answer 19

Rods and cones are specialized cells in the retina that work together to convert light into signals that the brain can interpret as vision.

Question 20

Cones Vs Rods

Answer 20

Rods respond to motion and are responsible for peripheral vision, dim light and shapes. Cones are responsible for colour vision, intense light and centre vision

Question 21

Fovea Centralis

Answer 21

a small depression in the retina of the eye where visual acuity is highest. The center of the field of vision is focused in this region, where retinal cones are particularly concentrated.

Question 22

Types of receptors and what they do

Answer 22

Photoreceptors (eyes), Chemoreceptors (tongue, nose, carotid arteries & brain), mechanoreceptors (ears,proprioceptors & touch), and Thermoreceptors (temperature)

Question 23

Vision defects

Answer 23

Astigmatism (uneven curvature of part of the cornea), Cataracts (lens becomes opaque), Glaucoma (Build-up of fluid in anterior chamber to lens), Colour Blindness, Myopia (nearsighted) & Hyperopia (farsighted)

Question 24

Chemistry of Vision

Answer 24

Rhodopsin: (visual purple) light pigment found in rods
Photopsin: in cones, reacts only to certain light wavelengths

Question 25

The 3 layers of neurons in the Retina

Answer 25

photoreceptor cells (rods and cones), bipolar cells, and ganglion cells

Question 26

Three sections of the Ear

Answer 26

1. Outer 2. Middle 3. Inner

Question 27

Pinna

Answer 27

Outer flap of the ear, which acts like a sound funnel, directing it to the auditory canal. Part of the Outer Ear

Question 28

Auditory Canal

Answer 28

Channel that carries sound waves to the eardrum and prevents invading particles from entering by producing earwax

Question 30

Tympanic membrane (eardrum)

Answer 30

the membrane of the middle ear, which vibrates in response to sound waves and separates outer & middle ear

Question 31

Ossicles

Answer 31

Amplifies/passes sound waves from eardrum to the oval window by 3 small bones: malleus (hammer), incus (anvil) & stapes (stirrup)

Question 32

Oval window

Answer 32

membrane-covered opening from the middle ear to the cochlea of the inner ear. ossicles transmit vibrations to the oval window, which leads to movement of fluid within the cochlea and activation of receptors for hearing.

Question 33

Eustachian tube

Answer 33

A narrow air filled tube that equalized pressure between internal and external ear. Also drains excessive fluid to the nasal cavity

Question 34

Vestibule

Answer 34

The vestibule is a bony chamber in the inner ear that helps maintain balance and eye movement. the utricle and saccule in your inner ear contain fluid and fine, hairlike sensors. These sensory hair cells help you keep your eyes focused on a target when your head is in motion.

Question 35

Cochlea

Answer 35

the spiral cavity of the inner ear containing the organ of Corti, which produces nerve impulses in response to sound vibrations, identifying sounds.

Question 36

Organ of Corti

Answer 36

a complex epithelial structure in the cochlea that contains thousands of hair cells, rests on the internal surface of the basilar membrane which produces nerve impulses in response to sound vibrations

Question 37

Basilar membrane

Answer 37

The basilar membrane is a structure in the inner ear that separates sounds into different frequencies. It's the main mechanical part of the cochlea

Question 38

Tinnitus

Answer 38

Tinnitus causes people to hear ringing, buzzing, or roaring in their ears or head, even when no external sound is present, coming from the malfunction of cochlea. Hair cells are damaged, bent or destroyed

Question 39

Cilia

Answer 39

Cilia are tiny hair-like projections in the inner ear that help with hearing, balance, and earwax removal.