human a and p lab 2 test 1

Meissner's corpuscle

A sensory receptor for light touch and texture; found in the dermal papillae.

Pacinian corpuscle

A sensory receptor for deep pressure and vibration; onion-shaped.

Where are Meissner's corpuscles located?

In the dermal papillae of the skin.

What does a Meissner's corpuscle look like?

A small, oval/swirl-like structure.

What does a Pacinian corpuscle look like?

An onion-like structure with concentric layers.

What does a Pacinian corpuscle detect?

Deep pressure and vibration.

What does a Meissner's corpuscle detect?

Light touch and texture.

Two-point threshold

The minimum distance at which two separate points of touch can be felt as two distinct sensations.

Taste bud

A sensory structure containing taste receptor cells that detect chemicals in food.

Where are taste buds located?

Primarily in the papillae of the tongue.

Olfactory epithelium

Specialized epithelium containing olfactory receptors used for smell.

Cilia on olfactory receptors

Structures that help detect odor molecules.

Classic tongue taste map—sweet

Front/tip of the tongue.

Classic tongue taste map—salty

Front sides of the tongue.

Classic tongue taste map—sour

Sides of the tongue.

Classic tongue taste map—bitter

Back of the tongue.

Auricle (pinna)

The visible external part of the ear that collects sound.

External auditory meatus

The ear canal that carries sound toward the tympanic membrane.

Tympanic membrane

The eardrum; separates the external and middle ear and vibrates in response to sound.

Malleus

First auditory ossicle; receives vibrations from the tympanic membrane.

Incus

Second auditory ossicle; passes vibrations from the malleus to the stapes.

Stapes

Third auditory ossicle; transmits vibrations toward the inner ear.

Auditory tube (Eustachian tube)

Connects the middle ear to the pharynx and equalizes pressure.

Cochlea

Spiral-shaped inner-ear structure responsible for hearing.

Semicircular canals

Structures involved in detecting rotational/angular head movements and balance.

Vestibule

Part of the inner ear involved in balance and detecting linear acceleration/head position.

Vestibulocochlear nerve (CN VIII)

Carries hearing and balance information from the inner ear to the brain.

Scala vestibuli

Upper chamber of the cochlea; contains perilymph.

Cochlear duct

The middle chamber of the cochlea; contains endolymph.

Scala tympani

Lower chamber of the cochlea; contains perilymph.

Perilymph

Fluid found in the scala vestibuli and scala tympani.

Endolymph

Fluid found inside the cochlear duct.

Vestibular membrane

Membrane separating the cochlear duct from the scala vestibuli.

Tectorial membrane

A membrane associated with the organ of Corti that interacts with hair cells during hearing.

Basilar membrane

Membrane supporting the organ of Corti.

Organ of Corti

Sensory organ of hearing located on the basilar membrane.

Where is the organ of Corti located?

In the cochlear duct on the basilar membrane.

What does the organ of Corti detect?

Sound/hearing.

Rinne test

Compares bone conduction with air conduction of sound.

Normal Rinne test

Air conduction is greater/longer than bone conduction.

Weber test

Tests sound localization by comparing hearing between the two ears.

Auditory acuity

A person's ability to hear sounds accurately.

Sound localization

The ability to determine where a sound is coming from.

Cornea

Clear anterior portion of the eye that allows light to enter and helps focus it.

Sclera

White outer layer of the eye that protects and supports the eyeball.

Optic nerve

Carries visual information from the retina to the brain.

Choroid coat

Vascular, pigmented layer between the sclera and retina that supplies the eye.

Ciliary body

Structure involved in producing aqueous humor and controlling lens shape for accommodation.

Lens

Transparent structure that focuses light onto the retina.

Iris

Colored portion of the eye that controls pupil size.

Pupil

Opening in the center of the iris through which light enters.

Anterior cavity

Space in the front portion of the eye containing aqueous humor.

Aqueous humor

Clear fluid filling the anterior cavity of the eye.

Retina

Inner layer of the eye containing photoreceptors.

Fovea centralis

Area of the retina with the sharpest, most detailed vision.

Optic disc

Area where the optic nerve exits the eye; contains no photoreceptors and creates the blind spot.

Posterior cavity

Large space behind the lens containing vitreous humor.

Vitreous humor

Gel-like substance filling the posterior cavity of the eye.

Superior rectus

Extraocular muscle that primarily moves the eye upward.

Inferior rectus

Extraocular muscle that primarily moves the eye downward.

Medial rectus

Extraocular muscle that moves the eye medially/toward the nose.

Lateral rectus

Extraocular muscle that moves the eye laterally/away from the nose.

Inferior oblique

Extraocular muscle that helps move the eye upward and laterally.

Lacrimal gland

Gland that produces tears.

Rods

Retinal photoreceptors specialized for dim-light vision and peripheral vision.

Cones

Retinal photoreceptors responsible for color and sharp vision, especially in bright light.

Visual acuity

The ability of the eye to distinguish fine details.

Astigmatism

A refractive error caused by an irregular curvature of the cornea or lens.

Near point of accommodation

The closest distance at which an object can be focused clearly.

Blind spot

The point on the retina where the optic nerve exits; no rods or cones are present.

Accommodation

The process by which the lens changes shape to focus on objects at different distances.

Pituitary gland

An endocrine gland with anterior and posterior lobes located at the base of the brain.

Anterior pituitary

Front lobe of the pituitary; darker and more granular on a histology slide.

Posterior pituitary

Back lobe of the pituitary; lighter-looking than the anterior lobe.

Thyroid gland

Endocrine gland in the neck that contains thyroid follicles.

Thyroid follicles

Round structures in the thyroid containing colloid; important for thyroid hormone storage.

Parathyroid glands

Small endocrine glands associated with the posterior surface of the thyroid.

How do you identify a parathyroid gland slide?

Look for a cord-like arrangement of cells; thyroid follicles may sometimes be nearby.

Adrenal gland

Endocrine gland located on top of each kidney.

Adrenal cortex

Outer region of the adrenal gland; cells tend to be arranged in columns.

Adrenal medulla

Inner/central region of the adrenal gland.

How do you distinguish adrenal cortex from medulla?

The cortex is the outer region and tends to have cells in columns; the medulla is the center.

Pancreas

Organ with both endocrine and exocrine functions.

Islets of Langerhans

Lighter-staining endocrine cell clusters scattered throughout the pancreas.

Exocrine pancreas

Darker/more numerous cell clusters surrounding the lighter pancreatic islets.

Ovaries

Female reproductive organs that also function as endocrine glands.

Testes

Male reproductive organs that also function as endocrine glands.

Erythrocytes

Red blood cells; carry oxygen and some carbon dioxide.

Leukocytes

White blood cells involved in immune defense.

Thrombocytes

Platelets; cell fragments involved in blood clotting.

Neutrophil

White blood cell with a multilobed nucleus and faint lavender/pink cytoplasmic granules.

Eosinophil

White blood cell with a bilobed nucleus and bright reddish/pink cytoplasmic granules.

Basophil

White blood cell with very dark bluish/black cytoplasmic granules that can obscure the nucleus.

Monocyte

Largest white blood cell; has a large bean-shaped/kidney-shaped nucleus and blue-gray cytoplasm.

Lymphocyte

Small white blood cell with a large round nucleus and only a thin rim of cytoplasm.

How do you identify a neutrophil?

Look for a multilobed nucleus and faint lavender/pink granules.

How do you identify an eosinophil?

Look for a bilobed nucleus and bright red/pink granules.

How do you identify a basophil?

Look for very dark blue/black granules.

How do you identify a monocyte?

Look for a very large cell with a kidney/bean-shaped nucleus.

How do you identify a lymphocyte?

Look for a small cell with a large round nucleus and a thin rim of blue cytoplasm.