Anatomy and Physiology Review: Special Senses, Endocrine, Blood, Heart, Vessels, and Lymphatic Systems

Vocabulary practice flashcards covering special senses anatomy, endocrine glands, blood composition, heart structure, circulation, and the lymphatic system.

Gustatory epithelial cells

Specialized cells within taste buds that detect taste and are replaced every $7$ to $10$ days.

Gustatory hairs

Microvilli that extend through the taste pore and bind to food molecules dissolved in saliva.

Five basic tastes

Sweet, sour, salty, bitter, and umami (savory).

Olfactory stem cells

Stem cells located in the olfactory epithelium that replace olfactory sensory neurons.

Cribiform plate

The bony structure through which the axons of the olfactory nerve pass to reach the olfactory bulbs.

Conjunctiva

A transparent membrane that lubricates and protects the eye.

Lacrimal gland

The gland that produces tears containing mucus, antibodies, and lysozyme.

Sclera

The white part of the eye's fibrous layer that protects the eye and provides shape and muscle attachment.

Cornea

The transparent front portion of the eye's fibrous layer that allows light to enter.

Choroid

The part of the vascular layer containing blood vessels to nourish the eye and melanin to absorb excess light.

Ciliary body

The structure containing muscles that change the lens shape for focusing.

Iris

The colored portion of the eye that controls the size of the pupil.

Retina neural layer

The layer of the retina containing photoreceptor cells, bipolar cells, and ganglion cells.

Rods

Photoreceptors that are very sensitive to light, used for night and black-and-white vision.

Cones

Photoreceptors that function best in bright light for color and sharp, detailed vision.

Optic disc

The blind spot of the eye where no photoreceptors are present.

Aqueous humor

The fluid located in the anterior segment that nourishes the cornea and lens.

Vitreous humor

A jelly-like substance in the posterior segment that maintains eye shape and supports the retina.

Tympanic membrane

The eardrum, which vibrates with sound and separates the external and middle ear.

Ossicles

The three bones of the middle ear: the malleus, incus, and stapes.

Pharyngotympanic tube

The auditory tube that equalizes air pressure between the middle ear and the throat.

Bony Labyrinth

The system consisting of the semicircular canals (balance), vestibule (position), and cochlea (hearing).

Utricle and Saccule

Parts of the membranous labyrinth that detect horizontal and vertical movement, respectively.

Hypothalamus

Endocrine organ located at the base of the brain, above the pituitary gland.

Humoral Stimuli

Hormone release triggered by changes in blood levels of ions or nutrients, such as blood calcium causing $PTH$ release.

Neural Stimuli

Hormone release triggered by nerve impulses, such as sympathetic nerves stimulating the adrenal medulla.

Hormonal Stimuli

Hormone release triggered by other hormones, such as those from the hypothalamus affecting the pituitary gland.

Adenohypophysis

The anterior pituitary lobe that produces and secretes its own hormones.

Neurohypophysis

The posterior pituitary lobe that stores and releases hormones made by the hypothalamus.

Infundibulum

The stalk that attaches the pituitary gland to the hypothalamus.

Isthmus

The tissue that connects the right and left lobes of the thyroid gland.

Parathyroid hormone (PTH)

Hormone secreted to regulate blood calcium levels.

Adrenal Cortex

The outer layer of the adrenal gland that produces steroid hormones to regulate stress and metabolism.

Adrenal Medulla

The inner layer of the adrenal gland that releases hormones for the fight-or-flight response.

Pancreatic islets

Also called Islets of Langerhans, containing alpha cells (glucagon) and beta cells (insulin).

Melatonin

Hormone secreted by the pineal gland to regulate circadian rhythms.

Atrial natriuretic peptide (ANP)

A hormone released by the heart to lower blood volume and blood pressure.

Erythropoietin (EPO)

A hormone released by the kidneys to stimulate red blood cell production.

Hematocrit

The percentage of total blood volume composed of red blood cells, approx $47\%$ in males and $42\%$ in females.

Albumin

A plasma protein that prevents water from leaving blood vessels.

Erythrocytes

Red blood cells that are biconcave, lack a nucleus and organelles, and consist of about $97\%$ hemoglobin.

Diapedesis

The process by which leukocytes leave blood vessels to fight pathogens in tissues.

Granulocytes

A class of leukocytes including neutrophils, eosinophils, and basophils.

Megakaryocytes

Large bone marrow cells that break off to form platelets (thrombocytes).

Red Bone Marrow

Active site of hematopoiesis found in the axial skeleton, girdles, and proximal epiphyses of the humerus and femur.

Myocardium

The thick middle layer of the heart wall made of cardiac muscle responsible for pumping.

Tricuspid Valve

The right atrioventricular valve located between the right atrium and right ventricle.

Chordae tendineae

Structural cords that attach valve cusps to papillary muscles to prevent valve prolapse.

Pulmonary circulation

The path of blood from the right ventricle to the lungs and back to the left atrium.

Sinoatrial (SA) node

The natural pacemaker of the heart's conducting system.

Tunica Media

The middle vessel layer made of smooth muscle responsible for vasoconstriction and vasodilation.

Vasa vasorum

Small blood vessels in the tunica externa of large vessels that supply the outer vessel wall.

Arterioles

The smallest arteries, known as resistance vessels, that regulate blood flow into capillaries.

Skeletal Muscle Pump

The mechanism where contracting muscles squeeze veins to push blood toward the heart.

Thoracic duct

The lymphatic duct that drains $\frac{3}{4}$ of the body and empties into the left venous angle.

Spleen

Lymphoid organ in the left upper abdomen that filters blood and removes old red blood cells.

Peyer's Patches

Aggregated lymphoid nodules in the distal small intestine that protect against digestive tract bacteria.