Anatomy Senses Test

Accessory structures of the eye

Eyelashes, lacrimal glands, extrinsic eye muscles

Components of the eyelid

Skin, muscle, connective tissue, conjunctiva

Conjunctiva

Thin mucous membrane; lubricates and protects the eye

Purpose of lacrimal glands

Produce tears to clean and moisten the eye

Why fluid can move between eye and nose

Tear ducts connect the eye and nasal cavity

How the cornea holds its shape

Collagen fibers and pressure from aqueous humor

Extra eye muscles in humans allow

More precise movement; up/down, left/right, rotation

Function of fat around organs

Protection, cushioning, insulation, stabilization

Ciliary body

Muscle that changes lens shape; enables accommodation

Sheep pupil shape vs human

Sheep pupil is horizontal/oval; human pupil is round

Vitreous humor

Thick gel that maintains eye shape and keeps retina in place

How cataracts affect vision

Cloudy, blurry, dim vision; difficulty focusing

Why retinal image is upside down

Light bends through the curved lens, flipping the image

Tapetum lucidum purpose

Reflects light for better night vision

Other name for blind spot

Optic disc

Why blind spot has no vision

No photoreceptors where optic nerve exits

Color of macula lutea

Yellow

Fovea centralis

Center of macula; highest concentration of cones; sharpest vision

Fibrous tunic

Outer protective layer; sclera and cornea

Vascular tunic

Middle blood-rich layer; choroid, ciliary body, iris

Sensory tunic

Retina; detects light

Ossicles

Three small bones that vibrate to transmit sound

Tympanic membrane

Vibrates when struck by sound waves

Semicircular canals

Fluid-filled loops that detect rotational balance

Cochlea

Snail-shaped structure with hair cells that convert sound to nerve impulses

Auditory tube

Connects middle ear to throat; equalizes pressure

Middle ear function

Eardrum vibrates

Inner ear function

Cochlea detects sound; semicircular canals detect rotation; vestibule detects linear movement

Three general senses

Touch, temperature, pain

Touch receptors

Mechanoreceptors detecting pressure and texture

Temperature receptors

Thermoreceptors detecting heat and cold

Pain receptors

Nociceptors detecting tissue damage

Receptor

Specialized neuron that detects stimuli

Thermoreceptor

Detects temperature changes

Baroreceptor

Detects pressure changes

Chemoreceptor

Detects chemical changes

Photoreceptor

Detects light

Nociceptor

Detects pain/tissue damage

Proprioceptor

Detects body position and movement

General senses

Widely distributed (skin, muscles, joints, organs)

Special senses

Located in specific organs (vision, hearing, taste, smell, equilibrium)

Lamellated corpuscles (Pacinian)

Detect pressure and vibration; found deep in skin

Sclera

Tough white outer layer; protects and maintains shape

Conjunctiva function

Protects sclera and inner eyelids

Lacrimal gland

Produces tears

Ciliary body

Changes lens shape; produces aqueous humor

Lens

Flexible structure that focuses light by changing shape

Aqueous humor

Watery fluid maintaining pressure and corneal shape

Vitreous humor

Gel that maintains eye shape and optical clarity

Optic disc

Blind spot; no photoreceptors

Macula lutea

Region of sharpest central vision

Retina

Contains rods and cones; converts light to nerve impulses

Fovea centralis

Highest visual acuity; most cones

Choroid

Vascular layer nourishing retina; absorbs stray light

Lacrimal sac

Collects tears before draining into nasal cavity

Suspensory ligaments

Connect ciliary body to lens

Aqueous humor purpose

Helps cornea keep rounded shape

Blood vessels of retina

Supply oxygen and nutrients

Cones

Photoreceptors for color and sharp vision

Rods

Photoreceptors for dim light

Iris

Controls amount of light entering eye

Pupil

Opening where light enters

Optic nerve

Carries visual signals to brain

Tapetum lucidum

Reflective layer for night vision (animals)

Five basic tastes

Sweet, sour, bitter, salty, umami

How smell and taste create flavor

Brain combines taste bud signals with smell receptor signals

Easiest jellybean test

With nose open; smell enhances flavor detection

Why food tastes bland when sick

Congestion blocks smell receptors

Sensory neurons per taste bud

50–100 receptor cells

Nerves for taste

Facial (VII), Glossopharyngeal (IX), Vagus (X)

Vallate papillae

Large, round, back of tongue; many taste buds

Fungiform papillae

Mushroom-shaped; front/sides; taste buds

Filiform papillae

Thin, rough; no taste buds; texture

What is adaptation

Reduced sensitivity after continuous stimulation

Why you don’t feel socks all day

Touch receptors adapt to constant pressure

Why nostrils adapted similarly to wintergreen

Both nostrils experience same odor intensity

How many scents identified

All of them

Why someone is more sensitive to smells

Stronger or more responsive smell receptors

Smelling lowest concentration means

Strong smelling ability

Why concentration order was easy

Strong scents and good recognition ability

What does the lacrimal apparatus do?

Produces tears; tears are antibacterial; includes glands and ducts draining into nasal cavity.

How do extrinsic muscles function in the eye?

Six muscles control precise and rapid eye movements.

What is the structure and function of the cornea?

Transparent, curved front layer that refracts light onto the retina.

What is the role of the sclera?

White, tough outer layer providing protection and structural support.

How does the choroid coat support the eye?

It nourishes the retina and absorbs excess light to prevent scattering.

What functions does the ciliary body perform?

Controls lens shape for focusing via muscles; produces aqueous humor.

Describe the lens and its function.

Flexible, transparent, biconvex structure that focuses light by changing shape.

What does the iris do?

Controls pupil size to regulate light entering the eye.

What is the retina and its function?

Innermost layer containing rods and cones; converts light into nerve signals.

Why is there a blind spot on the retina?

The optic nerve exits at the optic disc where no photoreceptors exist.

What causes nearsightedness (myopia)?

Eye is too long or cornea too curved; light focuses in front of retina.

What causes farsightedness (hyperopia)?

Eye is too short or cornea too flat; light focuses behind retina.

How do nearsighted and farsighted vision differ?

Nearsightedness blurs distant objects; farsightedness blurs near objects.

What is accommodation of the lens?

The lens changes shape via ciliary muscles to focus on near or far objects.

What is presbyopia and why does it happen?

Age-related lens stiffening and loss of elasticity; difficulty focusing on close objects.

What are the major differences between rod and cone cells?

Rods detect low light and black/white vision; cones detect color and bright light.

What is the importance of the fovea centralis?

It has a high density of cones for the sharpest, most detailed vision.

How is the macula lutea related to the fovea centralis?

The macula surrounds the fovea and supports detailed central vision.

What role do chemoreceptors play in survival?

Detect chemical changes like taste, smell, and blood chemistry (O2, CO2).

What do nociceptors detect?

Pain and harmful stimuli.