Final Study Flashcards
What is the external opening of the anal canal called?
Anus
What is the inferior part of the uterus called?
Cervix
What is fluid-filled cavity within a blastocyst called?
Blastocoele
Definition: Connecting stalk between the fetus and the placenta; contains the allantois, the umbilical arteries, and the umbilical vein.
Term: umbilical cord
The passageway in the temporal bone that leads to the tympanic membrane of the middle ear
external acoustic meatus
The process of spermatid differentiation that leads to the formation of physically mature sperm
spermiogenesis
A muscle of the middle ear whose contraction tenses the auditory ossicles and reduces the forces transmitted to the oval window.
stapedius
Tubular glands of the stomach whose cells produce acid enzymes intrinsic factor and hormones
gastric glands
Early stage in the developing embryo consisting of an outer trophblast and an inner cell mass
blstocys
A hormone released by most tissues, and especially by the kidneys, when oxygen levels decrease; stimulates erythropoiesis (red blood cell formation) in red bone marrow.
erythropoietin (EPO)
Receptors sensitive to temperature changes
thermoreceptors
Blood vessels that blood away from the heart toward the peripheral capillaries
arteries
The hypothalamic nucleus that coordinates thermoregulatory activities
pre-optic area
Inhalation or exhalation using only the diaphragm
diaphragmatic breathing
the production of lymphocytes from lymphoid stem cells
lymphopoiesis
Triangular region of the urinary bladder bounded by the exits of the ureters and the entrance of the urethra
trigone
Fluid contents of the membranous labyrinth (the saccule, utricle, semicircular ducts, and cochlear duct) of the internal ear.
endolymph
Disorder characterized by polyuria (excessive urination) and glycosuria (glucose in the urine), most commonly due to the inadequate production or diminished sensitivity to insulin with a resulting increase of blood glucose levels
diabetes mellitus
Tear gland on the posterior, lateral surface of the eye.
lacrimal gland
Transfer of blood from a donor directly into the bloodstream of another person.
transfusion
The most caudal of the brain regions, also known as the myelencephalon.
medulla oblongata
The auricle, external acoustic meatus, and tympanic membrane
external ear
The hormone secreted by C cells of the thyroid when calcium ion concentrations are abnormally high; restores homeostasis by increasing the rate of bone deposition and the rate of calcium loss by the kidneys.
calcitonin (CT)
Movement of air in and out of the lungs.
pulmonary ventilation
Sensory receptors in the skin, mucous membranes, and special sense organs that provide information about the external environment and our position within it.
exteroceptors
A muscular tube that carries urine from the urinary bladder to the exterior.
urethra
Sensory organs that monitor the position and movement of skeletal muscles and joints.
proprioceptors
Cranial nerves that provide sensations to the pharynx and posterior third of the tongue; they also carry motor fibers to the stylopharyngeus muscle.
glossopharyngeal nerves (N IX)
The inactive proenzyme that is secreted by chief cells of the gastric pits; after secretion it is converted to the proteolytic enzyme pepsin.
pepsinogen
A sensory region monitored by the posterior rami of a single spinal segment.
dermatome
Stem cells whose mitotic divisions give rise to other stem cells and spermatocytes.
spermatogonia
Fusion of a secondary oocyte and sperm to form a zygote.
fertilization
A membranous sac at the tip of a spermatozoon that contains hyaluronidase; also called acrosomal cap.
acrosome
Glands on the inner surface of the prepuce that produce a viscous, odorous secretion called smegma.
preputial glands
Sensory receptors monitoring the functions and status of internal organs and systems.
interoceptors
A class of steroid sex hormones that includes estradiol.
estrogens
An enzyme present in some exocrine secretions that has antibiotic properties.
lysozyme
Conical tip of the spinal cord that gives rise to the filum terminale.
conus medullaris
An axon that carries impulses away from the central nervous system.
efferent fiber
A violent hit to the head with resulting loss of consciousness
concussion
A fringes; used to describe the fingerlike processes that surround the entrance to the uterine tube.
fimbriae
Modified neurons in the retina that facilitate or inhibit communication between bipolar and ganglion cells.
amacrine cells
A duct that carries bile between the gallbladder and the common bile duct.
cystic duct
The condition marked by a decrease in the hematocrit, the hemoglobin content of the blood, or both.
anemia
Cranial nerves controlling the superior oblique muscle of the eye
trochlear nerves (N IV)
Lymphoid organ important for red blood cell phagocytosis, the immune response, and lymphocyte production.
spleen
A cell in nervous tissue that is specialized for intercellular communication through changes in membrane potential and synaptic connections.
neuron
A peripheral gland or muscle cell innervated by a motor neuron.
effector
The centers in the medulla oblongata that set the background pace of respiration; includes inspiratory and expiratory centers.
respiratory rhythmicity centers
Outer layer or region of an organ or bone.
cortex
Sensory organs that monitor the position and movement of skeletal muscles and joints.
proprioceptors
Regions where adjacent cardiocytes interlock and where gap junctions permit electrical coupling between the cells.
intercalated discs
Terminal axonal branches that end in axon terminals.
telodendria
The fluid ground substance of whole blood; what remains after the cells have been removed from a sample of whole blood.
plasma
Collection of neuron cell bodies in the peripheral nervous system.
ganglion/ganglia
Blood plasma from which clotting agents have been removed.
serum
Isolation of the central nervous system, from the general circulation; primarily the result of astrocyte regulation of capillary permeabilities.
blood brain barrier (BBB)
Receptors that have the ability to detect changes in pressure.
baroreceptors
Two pairs of flattened, bladelike teeth located at the front of the dental arches in both the upper and lower jaws.
incisors
A reduction in the diameter of arterioles due to the contraction of smooth muscles in the tunica media; increases peripheral resistance; may occur in response to local factors, through the action of hormones, or from the stimulation of the vasomotor center.
vasoconstriction
Sensory receptors monitoring the functions and status of internal organs and systems.
interoceptors
Removal of most of a patient’s blood followed by replacement of an equal amount of blood from donors.
exchange transfusion
A corticosteroid secreted by the zona fasciculata of the adrenal (suprarenal) cortex; a glucocorticoid.
corticosterone
Processes of the arachnoid mater that project into the superior sagittal sinus; sites where cerebrospinal fluid enters the venous circulation.
arachnoid granulations
Small secretory sacs or glands.
follicles
The innermost layer of the meninges bound to the underlying nervous tissue.
pia mater
The perilymph-filled chamber of the internal ear, adjacent to the basilar membrane; pressure changes there distort the round window; also called tympanic duct.
scala tympani
Large salivary glands that secrete saliva with high concentrations of salivary (alpha) amylase.
parotid glands
Network formed by branches of spinal nerves C5–T1 en route to innervate the upper limb.
brachial plexus
Inflammation of the stomach.
gastritis
Movable folds that cover the front of the eyeballs; also called palpebrae.
eyelids
The middle portion of the pharynx, bounded superiorly by the nasopharynx, anteriorly by the oral cavity, and inferiorly by the laryngopharynx.
oropharynx
Swallowing.
deglutition
The expanded ends of the olfactory tracts; the sites where the axons of the first cranial nerves (N I) synapse on central nervous system interneurons that lie inferior to the frontal lobes of the cerebrum.
olfactory bulbs
The bones of the middle ear: malleus, incus, and stapes.
auditory ossicles
The throat; a muscular passageway shared by the digestive and respiratory tracts.
pharynx
The sense of smell.
olfaction
Loose-fitting, fleshy pouch that encloses the testes of the male.
scrotum
Definition: Sperm production.
spermatogenesis
A pair of small laryngeal cartilages.
corniculate cartilages
A chamber or pocket.
antrum
An endocrine organ that is located in the sella turcica of the sphenoid bone and is connected to the hypothalamus by the infundibulum; includes the posterior lobe (neurohypophysis) and the anterior lobe (adenohypophysis); also called the hypophysis.
pituitary gland
An endocrine gland whose lobes are lateral to the thyroid cartilage of the larynx.
thyroid gland
A propagated change in the membrane potential of excitable cells, initiated by a change in the membrane permeability to sodium ions: see nerve impulse.
action potential
Stiffening of the penis prior to copulation due to the engorgement of the erectile tissues of the corpora cavernosa and the corpus spongiosum.
erection
The percentage of formed elements in a sample of blood; also called volume of packed red cells (VPRC) or packed cell volume (PCV).
hematocrit
A cell whose meiotic divisions will produce a single ovum and three polar bodies.
oocyte
Integumentary glands that secrete cerumen.
ceruminous glands
Steroid hormones produced by the adrenal (suprarenal) cortex.
corticosteroids
Lymphocytes capable of differentiating into plasma cells, which produce antibodies.
B cells
Regions in the central nervous system (CNS) that are dominated by myelinated axons.
white matter
Muscular ridges projecting from the walls of the ventricles of the heart.
trabeculae carneae
Disorder of the pituitary gland characterized by polyuria (excessive urination) and polydipsia (excessive thirst) that results from inadequate production of antidiuretic hormone (ADH).
diabetes insipidus
Longitudinal canal in the center of an osteon that contains blood vessels and nerves, also called the Haversian canal; a passageway along the longitudinal axis of the spinal cord that contains cerebrospinal fluid.
central canal
A fluid similar in composition to cerebrospinal fluid; found in the spaces between the bony labyrinth and the membranous labyrinth of the internal ear.
perilymph
Gelatinous membrane suspended over the hair cells of the spiral organ.
tectorial membrane
Phagocytic neuroglia in the central nervous system, derived from the monocytes of the blood.
microglia
An arteriole bringing blood to the glomerulus of the kidney.
afferent arterioles
A temporary structure in the uterine wall that permits diffusion between the fetal and maternal circulatory systems.
placenta
Thalamic nucleus involved in the integration of sensory information prior to projection to the cerebral hemispheres.
putamen
Liver cells.
hepatocytes
Nuclei in the hypothalamus that affect eating reflexes and behaviors; a component of the limbic system.
mammillary bodies
Serous membrane covering the outer surface of the heart; also called the visceral pericardium.
epicardium
Space between the superior portion of each of the three aortic valve cusps and the dilated portion of the wall of the ascending aorta.
aortic sinus
The primary estrogen secreted by ovarian follicles.
estradiol
Activated B cells that secrete antibodies.
plasma cells
An unusually high hematocrit due to the presence of excess numbers of formed elements, especially RBCs.
polycythemia
An interwoven network of blood vessels or passageways.
rete testis
Thyroxine (T4) and triiodothyronine (T3), hormones of the thyroid gland; hormones that stimulate tissue metabolism, energy utilization, and growth.
thyroid hormones
Proteolytic enzyme secreted by the chief cells of the gastric glands in the stomach.
pepsin
The middle part of the small intestine.
jejunum
Vascular connection between the pulmonary trunk and the aorta that functions throughout fetal life; normally closes at birth or shortly thereafter, and persists as the ligamentum arteriosum.
ductus arteriosus
In a skeletal muscle, the point of attachment that does not change position when the muscle contracts; usually defined in terms of movements from the anatomical position.
origin
Childbirth, delivery.
parturition
Fluid similar to perilymph or cerebrospinal fluid that fills the anterior chamber of the eye.
aqueous humor
Reversible constriction of smooth muscles around respiratory passageways, frequently caused by an allergic response.
asthma
The segment of the nephron between glomerular’s capsule and the nephron loop; the major site of active reabsorption from the filtrate.
proximal convoluted tubule (PCT)
Cortical area of the cerebrum that is responsible for the integration of sensory inputs and/or motor commands.
association area
The smaller, medial subdivision of the posterior funiculus.
gracile fasciculus
Having a normal blood volume.
normovolemic
Superficial layer of connective tissue surrounding an internal organ; fibers are continuous with those of surrounding tissues, providing support and stabilization.
adventitia
The midbrain.
mesencephalon
Descending tracts that carry involuntary motor commands issued by the red nucleus of the mesencephalon.
rubrospinal tracts
A fold of mucous membrane that guards the connection between the ileum and the cecum.
ileocecal valve
Small blood vessels, located between arterioles and venules, whose thin walls permit the diffusion of gases, nutrients, and wastes between the plasma and interstitial fluids.
capillaries
The nuclei and centers in the cerebrum and diencephalon that are involved with emotional states, memories, and behavioral drives.
limbic system
A passageway that carries sperm from the epididymis to the ejaculatory duct; also called the vas deferens.
ductus deferens
A muscular tube that connects the pharynx to the stomach
esophagus
The mucous membrane lining the uterus.
endometrium
Hormones that stimulate the gonads (testes or ovaries).
gonadotropins
A natural communication, direct or indirect, between an artery and a vein.
arteriovenous anastomoses
Flap-like structure that maintains unidirectional blood flow.
valves
An enzyme that breaks down hyaluronic acid; produced by some bacteria and found in the acrosomeof sperm.
hyaluronidase
Receptors sensitive to vibration.
lamellar corpuscles
A hormone released by most tissues, and especially by the kidneys, when oxygen levels decrease; stimulates erythropoiesis (red blood cell formation) in red bone marrow.
erythropoietin (EPO)
Microtubules in the cytoplasm of a neuron.
neurotubules
Small, posterior, medial area of the thalamus.
epithalamus
An arch or the space bounded by an arch; in the brain, an arching tract that connects the hippocampus with the mammillary bodies; in the eye, a slender pocket located where the epithelium of the ocular conjunctiva folds back on itself as the palpebral conjunctiva; in the vagina, the shallow recess surrounding the protrusion of the cervix.
fornix
Circulating antibodies.
immunoglobulins
A mineralocorticoid produced by the zona glomerulosa of the adrenal cortex; stimulates the kidneys to conserve sodium and water; secreted in response to the presence of angiotensin II.
aldosterone
An opening in the bony labyrinth of the internal ear that exposes the membranous wall of the tympanic duct to the air of the middle ear cavity.
round window
The formation of lymphocytes.
lymphocytopoiesis
Superficial layer of connective tissue surrounding an internal organ; fibers are continuous with those of surrounding tissues, providing support and stabilization.
adventitia
Portion of the retina providing the sharpest vision, with the highest concentration of cones; also called the fovea.
fovea centralis
The product of meiosis in the male, cells that differentiate into sperm.
spermatids
Surgical incision of the vulva to prevent laceration during delivery.
episiotomy
The superficial region of the adrenal gland that produces steroid hormones; also called the suprarenal cortex.
adrenal cortex
White blood cells.
leukocytes
A dilated segment of the internal carotid artery whose walls contain baroreceptors sensitive to changes in blood pressure.
carotid sinus
The period of intra-uterine development.
gestation
Distinct outgrowths of nerve cell dendrites that are the sites of synaptic axodendritic contact; they are absent in motor neurons and numerous in pyramidal cells of the cerebral cortex and Purkinje cells of the cerebellar cortex.
dendritic spines
The receptor, sensory neuron, motor neuron, and effector involved in a particular reflex; interneurons may or may not be present, depending on the reflex considered.
reflex arc
A decrease in receptor sensitivity or perception after chronic stimulation; a change in pupillary size in response to changes in light intensity; physiological responses that produce acclimatization.
adaptation
The vessels of the lymphatic system; also called lymphatics.
lymphatic vessels
A mucous membrane; the epithelium plus the lamina propria; also called mucous membrane.
mucosa
Small packets of cytoplasm that contain enzymes important in the clotting response; manufactured in the bone marrow by cells called megakaryocytes.
platelets
The segment of the nephron between the proximal and distal convoluted tubules that creates the concentration gradient; also called loop of Henle.
nephron loop
The anterior edge of the neural retina.
ora serrata
Ascending tracts carrying poorly localized touch, pressure, pain, vibration, and temperature sensations to the thalamus.
spinothalamic tracts
Region between the muscularis mucosae and the muscularis externa.
submucosa
A receptor complex, located in the saccule or utricle of the internal ear, that responds to linear acceleration or gravity.
macula
Isolation of the seminiferous tubules from the general circulation, due to the activities of the nurse (Sertoli) cells.
blood testis barrier
Meningeal space containing cerebrospinal fluid; the area between the arachnoid mater and the pia mater.
subarachnoid space
Hormones secreted by the zona fasciculata of the adrenal (suprarenal) cortex to modify glucose metabolism; cortisol and corticosterone are important examples.
glucocorticoids (GCs)
The fibrous, outer layer of the eye forming the white area of the anterior surface; a portion of the fibrous layer of the eye.
sclera
The shedding of blood and endometrial tissue at menses.
menstruation
The fluid ejaculate that contains spermatozoa and the secretions of accessory glands of the male reproductive tract.
semen
The primary estrogen secreted by ovarian follicles.
estradiol
Nerve cells forming a pathway from the brain or spinal cord to an effector (muscular or glandular) tissue.
motor neurons
Descending tracts of the extrapyramidal system, carrying involuntary motor commands issued by the vestibular nucleus to stabilize the position of the head.
vestibulospinal tracts
Hormone produced by enteroendocrine cells of the stomach, when exposed to mechanical stimuli or vagal stimulation, and the duodenum, when exposed to chyme containing undigested proteins.
gastrin
Involuntary, continual movement of the eyes as if to adjust to constant motion.
nystagmus
Gastric enzyme that breaks down milk proteins.
rennin
The middle germ layer that lies between the ectoderm and endoderm of the embryo.
mesoderm
The opposing surfaces of the teeth that come into contact when chewing food.
occlusal surface
Loose fold of skin that surrounds the glans penis (males) or the clitoris (females).
prepuce
Waste products eliminated by the digestive tract at the anus; contain indigestible residue, bacteria, mucus, and epithelial cells.
feces
Space between the spinal dura mater and the walls of the vertebral foramen; contains blood vessels and adipose tissue; a frequent site of injection for regional anesthesia.
epidural space
Term: white matter
Definition: Regions in the central nervous system (CNS) that are dominated by myelinated axons.
white matter
Situated behind or outside of the peritoneal cavity.
retroperitoneal
Placental hormone that stimulates the functional development of the mammary glands.
human placental lactogen (HPL)
The layer of peritoneum on the abdominal organs.
visceral peritoneum
Red blood cells (RBCs); have no nucleus and contain large quantities of hemoglobin.
erythrocytes
Midsagittal band of neural cortex on the surface of the cerebellum
vermis
Expanded portions of the cerebrum covered in neural cortex.
cerebral hemispheres
The release of a secondary oocyte, surrounded by cells of the corona radiata, after the rupture of the wall of a tertiary follicle; in females, the periodic release of an oocyte from an ovary.
ovulation
Type of lymphocyte that can kill target cells without previous sensitivity.
natural killer (NK) cells
A nerve bundle containing the myelinated preganglionic axons of sympathetic motor neurons en route to the sympathetic chain or to a collateral ganglion.
white ramus communicans
In nervous tissue, the spread of excitation from one neuron to many neurons; an organizational pattern common along sensory pathways of the central nervous system.
divergence
Glands that contain exocrine and endocrine cells, or an exocrine gland that produces serous and mucous secretions.
mixed glands
Overproduction and accumulation of peritoneal fluid
ascites
A digestive organ containing exocrine and endocrine tissues; the exocrine portion secretes pancreatic juice, and the endocrine portion secretes hormones, including insulin and glucagon.
pancreas
The collection of afferent and efferent fibers of the white matter of the cerebral hemispheres, visible on gross dissection of the brain.
internal capsule
The smallest living structural units in the human body.
cells
A fibrous extension of the spinal cord that extends from the conus medullaris to the coccygeal ligament.
filum terminale
The anterior portion of each cerebral hemisphere; thought to be involved with higher intellectual functions, predictions, and calculations.
prefrontal cortex
A portion of the limbic system that is concerned with the organization and storage of memories.
hippocampus
Sections of myelinated nerve fibers between two successive nodes.
internodes
Inability to speak.
aphasia
Glands of the male reproductive tract that produce roughly 60 percent of the volume of semen. Also known as seminal vesicles.
seminal glands
Cellular organelle that contains DNA, RNA, and proteins; a mass of gray matter in the CNS.
nucleus/nuclei
The production of milk by the mammary glands.
lactation
A narrow band of tissue connecting two larger masses.
isthmus
A receptor complex in the scala media of the cochlea that includes the inner and outer hair cells, supporting cells and structures, and the tectorial membrane; provides the sensation of hearing; also called the organ of Corti.
spiral organ
Groups of neurons between sensory and motor neurons that control a coordinated activity.
Interneurons
Removal of soluble substances and water by transfer across the peritoneum.
peritoneal dialysis
Diffuse network of gray matter that extends the entire length of the brainstem.
reticular formation
The vascular complex in the roof of the third and fourth ventricles of the brain, responsible for the production of cerebrospinal fluid.
choroid plexus
Lymphocytes whose secretions and other activities coordinate cell-mediated and antibody-mediated immunities; also called TH cells
helper T cells
The opening in the center of the iris through which light enters the eye.
pupil
Waxy secretion of ceruminous glands along the external acoustic meatus.
cerumen
Monthly cycle of gamete development in the ovaries, associated with cyclical changes in the production of sex hormones (estrogens and progestins).
ovarian cycle
The dilation of the bronchial passages; can be caused by sympathetic stimulation.
bronchodilation
Cells of the lymphatic system that play a role in the immune response.
lymphocytes
Hormone secreted by the pineal gland; inhibits secretion of MSH and GnRH.
melatonin
The fusion of male and female pronuclei following fertilization.
amphimixis
The layer of the peritoneum (serous sac) that lines the abdominal walls.
parietal peritoneum
Type of lymphocyte that can kill target cells without previous sensitivity.
natural killer (NK) cells
A hormone that causes an increase in systemic blood pressure, stimulates the secretion of aldosterone, promotes thirst, and causes the release of antidiuretic hormone; angiotensin-converting enzyme (ACE) in lung capillaries converts angiotensin I into angiotensin II.
angiotensin II
The large, elastic artery that carries blood away from the left ventricle and into the systemic circuit.
aorta
The outermost layer of the eye, composed of the sclera and cornea; also called fibrous tunic.
fibrous layer
One of the large, dome-shaped papillae on the superior surface of the tongue that forms a V, separating the body of the tongue from the root.
vallate papillae
The tubular component of the membranous labyrinth of the internal ear; responds to rotational movements of the head.
semicircular duct
An abnormally high blood volume.
hypervolemic
Network of nerves arising from the anterior rami of the first four cervical spinal nerves.
cervical plexus
The transparent refractive structure of the eye that is between the iris and the vitreous humor.
lens
Cell division that produces gametes with half of the normal somatic chromosome complement.
meiosis
The reduction in size of the bronchial passages.
bronchoconstriction
Cells in the pancreatic islets that secrete glucagon.
alpha (α) cells
Inability to coordinate muscular movement.
ataxia
An extra-embryonic membrane, consisting of the trophoblast and underlying mesoderm, that forms the placenta.
chorion
Opening in the bony labyrinth where the stapes attaches to the membranous wall of the scala vestibuli (vestibular duct).
oval window
Blood protein produced by the liver that is converted to angiotensin I by the enzyme renin.
angiotensinogen
A modified sympathetic ganglion that secretes catecholamines into the blood during sympathetic activation; the core of the adrenal gland; also called suprarenal medulla.
adrenal medulla
See ductus deferens.
vas deferens
Thymic hormone essential to the development and differentiation of T cells.
thymosin
The pear-shaped reservoir for bile after it is secreted by the liver.
gallbladder
Exchange vessels that are similar in general structure to fenestrated capillaries. The two differ in size (sinusoids are larger and more irregular in cross section), continuity (sinusoids have gaps between endothelial cells), and support (sinusoids have thin basement membranes, if present at all).
sinusoids
Abnormally low platelet count in the circulating blood.
thrombocytopenia
The second cranial nerves, which carry signals from the retina of the eye to the optic chiasm.
optic nerves (N II)
Positive feedback along a chain of neurons such that they remain active once stimulated.
reverberation
An elevated epithelial projection on the surface of the breast, containing the openings of the lactiferous sinuses.
nipple
Stem cells in the ovaries whose divisions give rise to oocytes.
oogonia
The base of an organ such as the stomach, uterus, or gallbladder
fundus
Male gametes; also called spermatozoon/spermatozoa.
sperm
Formation and development of an oocyte.
oogenesis
Terminal pockets at the end of the respiratory tree, lined by a simple squamous epithelium and surrounded by a capillary network; sites of gas exchange with the blood; a bony socket that holds the root of a tooth.
alveolus/alveoli
Enzyme necessary for the conversion of angiotensin I to angiotensin II.
angiotensin-converting enzyme (ACE)
Network of vessels that carry blood from capillaries in the hypothalamus to capillaries in the anterior lobe of the pituitary gland (adenohypophysis).
hypophyseal portal system
Receptors that can detect mechanical stimuli, such as touch, pressure, or vibration.
mechanoreceptors
Tracts carrying information from the spinal cord to the brain.
ascending tracts
The cessation of uterine cycles as a consequence of the aging process and exhaustion of viable follicles.
menopause
Vessels between the aortic valve and the entrance to the right atrium; the circulatory system other than vessels of the pulmonary circuit.
systemic circuit
Small arterial branches that deliver blood to a capillary network.
arterioles
Any agent or factor that induces or increases the risk of abnormal prenatal development.
teratogen
Painful menstruation.
dysmenorrhea
A compact mass; usually refers to compacted ingested material (food) on its way to the stomach.
bolus
A hormone secreted by the parathyroid glands when blood calcium levels decrease below the normal range; causes increased osteoclast activity, increased intestinal calcium uptake, and decreased calcium ion loss by the kidneys.
parathyroid hormone (PTH)
Series of fibers connecting the ciliary body with the lens of the eye
ciliary zonule
Sudden loss of neurologic function with complete recovery.
transient ischemic attack (TIA)
Passageway that transports tears from the nasolacrimal sac to the nasal cavity.
nasolacrimal duct
A hormone, produced by nurse cells of the testes and follicular cells of the ovaries, that inhibits the secretion of follicle-stimulating hormone by the anterior lobe of the pituitary gland.
inhibin
Region of the adrenal cortex that secretes androgens.
zona reticularis
Compounds containing relatively small lipids bound to a protein.
lipoproteins
The superficial region of the adrenal gland that produces steroid hormones; also called the suprarenal cortex.
adrenal cortex
The fibrous sac that surrounds the heart, and whose inner, serous lining is continuous with the epicardium.
pericardium
T lymphocytes that provide immunologic memory, enabling an enhanced immune response when reexposed to a specific antigen.
memory T cells
Fluid bathing the internal and external surfaces of the central nervous system; secreted by the choroid plexus.
cerebrospinal fluid (CSF)
Gastric region between the body of the stomach and the duodenum; includes the pyloric sphincter.
pylorus
A region of the temporal lobe that is visible only after opening the lateral sulcus.
insula
Membrane that separates the external acoustic meatus from the middle ear; membrane whose vibrations are transferred to the auditory ossicles and ultimately to the oval window; the “eardrum.”
tympanic membrane
A thyroid hormone; also called T4 or tetraiodothyronine.
thyroxine
Impaired ability to comprehend written words.
dyslexia
One of the three primary germ layers; covers the surface of the embryo and gives rise to the nervous system, the epidermis and associated glands, and a variety of other structures.
ectoderm
The brain and spinal cord.
central nervous system (CNS)
The floor of the diencephalon; region of the brain containing centers involved with the unconscious regulation of visceral functions, emotions, drives, and the coordination of neural and endocrine functions.
hypothalamus
Sensory processes of a neuron.
dendrites
A disease caused by the human immunodeficiency virus (HIV); characterized by the destruction of helper T cells and a resulting severe impairment of the immune response.
acquired immunodeficiency syndrome (AIDS)
Cells of the pancreatic islets that secrete insulin in response to increased blood sugar concentrations.
beta cells
A small erectile organ of the female that is the developmental equivalent of the male penis.
clitoris
A class of steroid sex hormones that includes estradiol.
estrogens
Region of the pharynx that lies superior to the soft palate.
nasopharynx
Cells of the gastric glands that secrete hydrochloric acid and intrinsic factor.
parietal cells
The medulla oblongata.
myelencephalon
The connective tissue framework of an organ; distinguished from the functional cells (parenchyma) of that organ.
stroma
A wave of smooth muscle contractions that propels materials along the lumen of a tube such as the digestive tract, the ureters, or the ductus deferens.
peristalsis
The thick layer of smooth muscle in the wall of the uterus.
myometrium
Blood that has been removed, stored, and then infused back into the same individual.
autologous transfusion
Secretory cells of the pineal gland.
pinealocytes
The ejection of semen from the penis as the result of muscular contractions of the bulbospongiosus and ischiocavernosus muscles.
ejaculation
Folds in the laryngeal wall containing elastic ligaments whose tension can be voluntarily adjusted; the true vocal cords, responsible for phonation.
vocal folds
Chamber that receives bile from the common bile duct and pancreatic secretions from the pancreatic duct.
duodenal ampulla
In the nervous system, the innervation of a single neuron by the axons from several neurons; this is most common along motor pathways.
convergence
An accessory gland of the male reproductive tract, contributing about one-third of the volume of semen.
prostate
Pain receptors.
nociceptors
An arteriole carrying blood away from the glomerulus of the kidney.
efferent arteriole
The occlusion of a blood vessel that supplies a portion of the brain, resulting in damage to the dependent neurons; also called stroke.
cerebrovascular accident (CVA)
Sensory cells of the internal ear.
hair cells
The portion of the metencephalon anterior to the cerebellum.
pons
Normal position of the uterus, with the superior surface bent forward.
anteflexion
Growth and the acquisition of increasing structural and functional complexity; includes the period from conception to maturity.
development
The smallest of the plasma proteins; function as transport proteins and important in contributing to plasma oncotic pressure.
albumins
Groove in the surface of a cerebral hemisphere, between the primary sensory and primary motor areas of the cortex.
central sulcus
Cranial nerves that control the extra-ocular muscles other than the superior oblique and the lateral rectus.
oculomotor nerves (N III)
Lymphoid nodules in the wall of the pharynx; the palatine, pharyngeal, and lingual tonsils.
tonsils
White blood cell formation.
leukopoiesis
The area monitored by a single sensory receptor.
receptive field
Ring-shaped cartilage that forms the inferior margin of the larynx.
cricoid cartilage
The scar tissue that remains after degeneration of the corpus luteum at the end of a uterine cycle.
corpus albicans
A hormone produced by hypothalamic cells and secreted into capillaries at the posterior lobe of the pituitary gland (neurohypophysis); stimulates smooth muscle contractions of the uterus or mammary glands in females and the prostate gland in males.
oxytocin
Red blood cell formation.
erythropoiesis
A surface antigen that may be present (Rh positive) or absent (Rh negative) from the surfaces of red blood cells.
Rh factor
An estimate of the number of each type of white blood cell on the basis of a random sampling of 100 white blood cells.
differential count
The portion of the anterior lobe of the pituitary gland (adenohypophysis) that is immediately adjacent to the posterior lobe of the pituitary gland (neurohypophysis) and the infundibulum.
pars intermedia
The portion of the anterior lobe of the pituitary gland (adenohypophysis) that wraps around the infundibulum superior to the posterior lobe (neurohypophysis).
pars tuberalis
The processing centers for sensations that arrive from the vestibular apparatus of the internal ear, located near the border between the pons and the medulla oblongata.
vestibular nuclei
Transparent portion of the fibrous layer of the anterior surface of the eye.
cornea
A congenital condition resulting from the inadequate synthesis of one of the clotting factors.
hemophilia
A reflex with interneurons interposed between the sensory fiber and the motor neuron(s).
polysynaptic reflex
Slender conical projections from the dorsal surface of the anterior two-thirds of the tongue.
filiform papillae
Mucosal folds in the laryngeal walls that do not play a role in sound production; the false vocal cords.
vestibular folds
The roof of the mesencephalon of the brain.
tectum
Specialized cardiocytes that relay the contractile stimulus to the bundle of His, the bundle branches, the Purkinje fibers, and the ventricular myocardium; located at the boundary between the atria and ventricles.
atrioventricularnode (AV node)
The perilymph-filled chamber of the internal ear, adjacent to the vestibular membrane; pressure waves are induced by movement of the stapes at the oval window; also called vestibular duct.
scala vestibuli
A modified sympathetic ganglion that secretes catecholamines into the blood during sympathetic activation; the core of the adrenal gland; also called suprarenal medulla.
adrenal medulla
Descending tracts of the extrapyramidal system, carrying involuntary motor commands issued by the vestibular nucleus to stabilize the position of the head.
vestibulospinal tracts
Aggregation of red blood cells due to interactions between surface antigens and plasma agglutinins.
agglutination
Receptors that are sensitive to light.
photoreceptors
Lymphocytes responsible for cellular immunity, and for the coordination and regulation of the immune response; include regulatory T cells (helpers and suppressors) and cytotoxic (killer) T cells.
T cells
Nervous tissue in the posterior portion of the roof of the diencephalon, responsible for secreting melatonin.
pineal gland
A small bundle; usually refers to a collection of nerve axons or muscle fibers.
fasciculus
Paralysis of the upper and lower limbs.
quadriplegia
A layer of follicle cells surrounding an oocyte at ovulation.
corona radiata
The plasma membrane of an axon, continuous with the plasma membrane of the cell body and dendrites and distinct from any glial cell coverings.
axolemma
Activation process that must occur before a sperm can successfully fertilize an oocyte; occurs in the vagina following ejaculation.
capacitation
Chewing.
mastication
Blood vessels that supply the walls of large arteries and veins.
vasa vasorum
The anterior lobe of the pituitary gland, also called the anterior pituitary.
adenohypophysis
One of the corticosteroids secreted by the zona fasciculata of the adrenal cortex; a glucocorticoid.
cortisol
Spermatic vessels, nerves, lymphatics, and the ductus deferens, extending between the testes and the proximal end of the inguinal canal.
spermatic cords
One of the three primary germ layers; the layer on the undersurface of the embryonic disc that gives rise to the epithelia and glands of the digestive system, the respiratory system, and portions of the urinary system.
endoderm
Fluid-filled chambers; in the heart, one of the large chambers discharging blood into the pulmonary or systemic circuits; in the brain, one of four fluid-filled interior chambers.
ventricles
Bundle of spinal nerve roots arising from the lumbosacral enlargement and medullary cone of the adult spinal cord; they extend caudally inside the vertebral canal en route to lumbar and sacral segments.
cauda equina
Sensory receptors in the skin, mucous membranes, and special sense organs that provide information about the external environment and our position within it.
exteroceptors
Isolation of the central nervous system, from the general circulation; primarily the result of astrocyte regulation of capillary permeabilities.
blood brain barrier (BBB)
The auditory ossicle attached to the tympanic membrane.
stapes
Small lobes or subdivisions of a lobe.
lobules
Receptors that have the ability to detect changes in the concentrations of dissolved compounds or gases, mainly CO2 and O2.
chemoreceptors
Thin-walled veins that receive blood from capillaries.
venules
Disintegration of an axon and its myelin sheath distal to an injury site.
wallerian degeneration
The region of the stomach surrounding its connection with the esophagus.
cardia
Supporting cells of the seminiferous tubules of the testis; responsible for the differentiation of spermatids, the maintenance of the blood testis barrier, and the secretion of inhibin, androgen-binding protein, and Müllerian-inhibiting factor; also called Sertoli cells.
nurse cells
Division of the pharynx inferior to the epiglottis and superior to the esophagus.
laryngopharynx
Touch receptors located within dermal papillae adjacent to the basement membrane of the epidermis; also called Meissner’s corpuscles.
tactile corpuscles
Lymphoid organ, site of T cell development and maturation.
thymus
The outer part of the serous pericardium.
parietal layer of the serous pericardium
Neuroglia responsible for the neurilemma that surrounds axons in the peripheral nervous system.
Schwann cells
Collection of neuron cell bodies in the peripheral nervous system
ganglion/ganglia
The motor association area between the precentral gyrus and the prefrontal area.
premotor cortex
Chest pain.
angina
A division of the brain that includes the epithalamus, thalamus, and hypothalamus.
diencephalon
Areas in the central nervous system dominated by nerve cell bodies, glial cells, and unmyelinated axons.
gray matter
The central auditory ossicle, situated between the malleus and the stapes in the middle ear cavity.
incus
Four small glands embedded in the posterior surface of the thyroid gland that secrete parathyroid hormone.
parathyroid glands
An arch or the space bounded by an arch; in the brain, an arching tract that connects the hippocampus with the mammillary bodies; in the eye, a slender pocket located where the epithelium of the ocular conjunctiva folds back on itself as the palpebral conjunctiva; in the vagina, the shallow recess surrounding the protrusion of the cervix.
fornix
White blood cells that are very numerous and normally the first of the mobile phagocytic cells to arrive at an area of injury or infection.
neutrophils
Pale region in the interior of lymphoid tissues or lymphoid nodules, where cell divisions occur that produce additional lymphocytes.
germinal center
The membranous labyrinth that contains the organs of hearing and equilibrium; also called inner ear.
internal ear
A mixture of buffers and digestive enzymes that is discharged into the duodenum under the stimulation of the enzymes secretin and cholecystokinin.
pancreatic juice
Middle, vascular layer in the wall of the eye.
choroid
The opening that permits fluid movement between the lateral and third ventricles.
interventricular foramen
Acetylcholine receptors on the surfaces of sympathetic and parasympathetic ganglion cells; respond to the compound nicotine.
nicotinic receptors
Phagocytic cells of the liver sinusoids; also called Kupffer cells.
stellate macrophages
The innermost layer of the eye, lining the vitreous chamber; also known as the inner layer.
retina
A closed sac connected to the cecum of the large intestine; also called vermiform appendix.
appendix
Hormone secreted by the pineal gland; inhibits secretion of MSH and GnRH.
melatonin
The simple squamous epithelium that lines the heart and is continuous with the endothelium of the great vessels.
endocardium
The female pudendum (external genitalia).
vulva
Pain resulting from compression of the roots of the sciatic nerve
sciatica
Heart attack; damage to the heart muscle due to an interruption of regional coronary circulation.
myocardial infarction (MI)
The stoppage of bleeding.
hemostasis
Inflammation of the urinary bladder.
cystitis
A newborn infant, or baby.
neonate
All nervous tissue outside the central nervous system.
peripheral nervous system (PNS)
Inflammation of the urethra.
urethritis
The serous membrane that lines the wall of the pulmonary cavity.
parietal pleura
Gastric cells near the base of gastric glands that secrete pepsinogen.
chief cells
Mucous glands at the base of the penis that secrete into the penile urethra; the equivalent of the greater vestibular glands of females; also called Cowper’s glands.
bulbo-urethral glands
Cells of the sinoatrial (SA) node that set the pace of cardiac contraction.
pacemaker cells
Supporting fibers that extend laterally from the surface of the spinal cord, tying the pia mater to the dura mater and providing lateral support for the spinal cord.
denticulate ligaments
Dural partition that separates the cerebral hemispheres from the cerebellum.
tentorium cerebelli
A reflex where the sensory afferent synapses directly on the motor efferent.
monosynaptic reflex
The developmental stage beginning at fertilization and ending at the start of the third developmental month.
embryo
The granulocytes and agranulocytes of whole blood; also called leukocytes.
white blood cells (WBCs)
Cells of the central nervous system and peripheral nervous system that support and protect neurons; also called glial cells.
neuroglia
Saclike pouches along the length of the large intestine that result from tension in the teniae coli.
haustra
The crossing point of the optic nerves.
optic chiasm
Bundle of axons linking centers in the left and right cerebral hemispheres.
corpus callosum
Lipid secretion that coats alveolar surfaces of the lungs and prevents their collapse.
surfactant
Membrane receptors sensitive to norepinephrine or epinephrine; stimulation usually results in excitation of the target cell.
alpha (α) receptors
A complex cartilaginous structure that surrounds and protects the glottis and vocal cords; the superior margin is bound to the hyoid bone and the inferior margin is bound to the trachea.
larynx
The proximal 25 cm (9.8 in.) of the small intestine that contains short villi and submucosal glands.
duodenum
The fertilized ovum prior to the start of cleavage.
zygote
A semifluid mixture of ingested food and digestive secretions that is found in the stomach as digestion proceeds.
chyme
The potential difference, measured across a plasma membrane and expressed in millivolts, that results from the uneven distribution of positive and negative ions across the plasma membrane; also called transmembrane potential.
membrane potential
Poorly localized centers in the reticular formation of the medulla of the brain; includes cardioacceleratory, cardioinhibitory, and vasomotor centers.
cardiovascular centers
The vein that carries blood from the parts of the body inferior to the heart to the right atrium.
inferior vena cava
A hormone, secreted by the duodenum, that stimulates the production of buffers by the pancreas and inhibits gastric activity.
secretin
Calcium carbonate crystals embedded in a gelatinous matrix; located on each macula of the vestibule.
otoliths
A plasma protein that is the soluble precursor of the insoluble protein fibrin.
fibrinogen
One of the basal nuclei involved with the subconscious control of skeletal muscular activity.
caudate nucleus
The proximal portion of the axon, adjacent to the axon hillock, where an action potential first appears.
initial segment
The fibrous strand found in the adult that is the remnant of the ductus arteriosus of the fetus.
ligamentum arteriosum
Vessels that connect an arteriole to a venule and provide blood to a capillary plexus.
metarterioles
Internal chamber in a tooth, containing blood vessels, lymphatics, nerves, and the cells that maintain the dentin.
pulp cavity
Openings in the roof of the fourth ventricle that permit the circulation of cerebrospinal fluid into the subarachnoid space.
lateral apertures
Fluid-filled chambers; in the heart, one of the large chambers discharging blood into the pulmonary or systemic circuits; in the brain, one of four fluid-filled interior chambers.
ventricles
Fluid bathing the internal and external surfaces of the central nervous system; secreted by the choroid plexus.
cerebrospinal fluid (CSF)
Paralysis of the upper limbs.
paraplegia
Ring-shaped cartilages that form the inferior margin of the larynx.
cricoid cartilages
The largest chamber of the vestibular apparatus of the internal ear; contains a macula important for providing sensations of gravity and linear acceleration in a horizontal dimension.
utricle
The body of a neuron; also called soma.
cell body
Mucosal folds in the lining of the empty stomach that disappear as gastric distension occurs; folds in the urinary bladder.
ugae
Protein composed of four globular subunits, each bound to a single molecule of heme; the protein found in red blood cells that gives them the ability to transport oxygen in the blood.
hemoglobin (Hb)
Curving sheet of dura mater that extends between the two cerebral hemispheres; encloses the superior sagittal sinus.
falx cerebri
The progesterone-secreting mass of follicle cells that develops in the ovary after ovulation.
corpus luteum
Removal of the tonsil(s).
tonsillectomy
Components of the urinary system; organs that function in the regulation of blood composition, including the excretion of wastes and the maintenance of normal fluid and electrolyte balances.
kidneys
The distal portion of the rectum that contains the anal columns and ends at the anus.
anal canal
A layer of stratified squamous epithelium that covers the inner surfaces of the eyelids and the anterior surface of the eye to the edges of the cornea.
conjunctiva
A pair of small cartilages in the larynx.
cuneiform cartilages
The initial portion of the nephron, consisting of an expanded chamber that encloses the glomerulus.
renal corpuscle
Sensory nerve endings that contact special receptors called Merkel cells, located within the deeper layers of the epidermis; also called Merkel’s discs.
tactile discs
The infectious agent that causes acquired immunodeficiency syndrome (AIDS).
human immunodeficiency virus (HIV)
The S-shaped region of the colon between the descending colon and the rectum.
sigmoid colon
Blood clot.
thrombus
A weakening in the arterial wall causing an outpouching or enlargement of an artery.
aneurysm
Cranial nerves that provide sensory information from the lower portions of the face (including the upper and lower jaws) and deliver motor commands to the muscles of mastication (chewing).
trigeminal nerves (N V)
Secretion of the preputial glands of the penis or clitoris.
smegma
The primary motor cortex of a cerebral hemisphere, located anterior to the central sulcus.
precentral gyrus
Short duct that passes within the walls of the prostate and connect the ductus deferens with the prostatic urethra.
ejaculatory duct
Globular plasma proteins with a variety of important functions.
globulins
The movement of cells of the inner cell mass that creates the three primary germ layers of the embryo.
gastrulation
A hormone, produced by the pars intermedia of the anterior lobe of the pituitary gland (adenohypophysis), that stimulates melanin production.
melanocyte-stimulating hormone (MSH)
The floor of the diencephalon; region of the brain containing centers involved with the unconscious regulation of visceral functions, emotions, drives, and the coordination of neural and endocrine functions.
hypothalamus
The innermost layer of the meninges bound to the underlying nervous tissue.
pia mater
Blood vessels carrying blood from capillary beds toward the heart.
veins
The enzyme released by cells of the juxtaglomerular complex when renal blood flow decreases; converts angiotensinogen to angiotensin I.
renin
Endolymph-filled tubes that enclose the receptors of the internal ear.
membranous labyrinth
A collection of visceral motor neurons outside the central nervous system.
autonomic ganglion
The vessel that carries blood from the intestinal capillaries to the sinusoids of the liver.
hepatic portal vein
Red bone marrow cells responsible for the formation of platelets.
megakaryocytes
The sense of taste.
gustation
Blood vessels carrying blood from capillary beds toward the heart
veins
An area of dead cells that results from an interruption of blood flow.
infarct
Site of communication between a nerve cell and some other cell; if the other cell is not a neuron, the term neuromuscular junction or neuroglandular junction is often used.
synapse
Lymphocytes involved in cell-mediated immunity that kill target cells by direct contact or by the secretion of lymphotoxins; also called killer T cells and TC cells.
cytotoxic T cells
Movement of white blood cells through the walls of blood vessels by migration between adjacent endothelial cells.
diapedesis
The posterior lobe of the pituitary gland, or pars nervosa; contains the axons of hypothalamic neurons, which release OXT and ADH.
neurohypophysis
A membrane that forms during development and coversthe entrance to the vagina.
hymen
Descending tracts that carry information/commands from the cerebral cortex to nuclei and centers in the brainstem.
corticobulbar tracts
One of the thyroid hormones.
triiodothyronine (T3)
The terminal portions of the intestinal tract, consisting of the colon, the rectum, and the anal canal.
large intestine
The extensive collection of lymphoid tissues linked with the epithelia of the digestive, respiratory, urinary, and reproductive tracts.
mucosa-associated lymphoid tissue (MALT)
To break down red blood cells.
hemolyze
The efferent division of the nervous system that innervates skeletal muscles.
somatic nervous system (SNS)
Coiled duct that connects the rete testis to the ductus deferens; site of functional maturation of sperm.
epididymis
A posterior tilting of the uterus that has no clinical significance.
retroflexion
Centers, nuclei, tracts, ganglia, and nerves involved in the unconscious regulation of visceral functions; includes components of the central nervous system and peripheral nervous system
autonomic nervous system (ANS)
A chamber; in the internal ear, the term refers to the utricle, saccule, and semicircular ducts; also refers to (1) a region of the female external genitalia, (2) the space within the fleshy portion of the nose between the nostrils, and (3) the space between the ventricular folds and the vocal folds of the larynx.
vestibule
Blade-shaped flap of tissue, reinforced by cartilage, that is attached to the posterior and superior surface of the thyroid cartilage; it folds over the entrance to the larynx during swallowing.
epiglottis
Pertaining to the body.
somatic
Flap-like structure that maintains unidirectional blood flow.
valves
A localized region where blood vessels, lymphatic vessels, nerves, and/or other anatomical structures are attached to an organ.
hilum
Ascending tracts carrying sensory information to the cerebellum.
spinocerebellar tracts
Hormone synthesized in the hypothalamus and secreted at the posterior pituitary; causes water retention at the kidneys and an increase in blood pressure.
antidiuretic hormone (ADH)
Mass of erectile tissue that surrounds the urethra in the penis and expands distally to form the glans.
corpus spongiosum
Pertaining to viscera (internal organs) or their outer coverings.
visceral
The duodenum, jejunum, and ileum; the digestive tract between the stomach and large intestine.
small intestine
Membrane receptors sensitive to acetylcholine and to muscarine, a toxin produced by certain mushrooms; located at all parasympathetic neuromuscular and neuroglandular junctions and at a few sympathetic neuromuscular and neuroglandular junctions.
muscarinic receptors
The layer of the inner cell mass facing the amniotic cavity prior to gastrulation.
epiblast
Fluid bathing the internal and external surfaces of the central nervous system; secreted by the choroid plexus.
cerebrospinal fluid (CSF)
Covered on all sides by the visceral peritoneum.
intraperitoneal
The primary sensory cortex, where touch, vibration, pain, temperature, and taste sensations arrive and are consciously perceived.
postcentral gyrus
The macula densa and the juxtaglomerular cells; a complex responsible for the release of renin and erythropoietin.
juxtaglomerular complex
Possessing half the normal number of chromosomes; a characteristic of gametes.
haploid
The yolk sac, amnion, chorion, and allantois.
extra-embryonic membranes
A dangling, fleshy extension of the soft palate.
uvula
The central membranous tube within the cochlea that is filled with endolymph and contains the spiral organ (organ of Corti); also called scala media.
cochlear duct
Thin-walled chambers of the heart that receive venous blood from the pulmonary or systemic circuits.
atria
The fold of dura mater extending across the sella turcica and hypophyseal fossa.
diaphragma sellae
Nervous tissue in the posterior portion of the roof of the diencephalon, responsible for secreting melatonin.
pineal gland
The pons and cerebellum of the brain.
metencephalon
The resistance to flow that a fluid exhibits as a result of molecular interactions within the fluid.
viscosity
Curving sheet of dura mater that projects forward from the internal occipital crest inferior to the tentorium.
falx cerebelli
The windpipe, an airway extending from the larynx to the primary bronchi.
trachea
Specialized membranes that line the vertebral canal and provide protection, stabilization, nutrition, and shock absorption to the spinal cord.
spinal meninges
One of 31 pairs of nerves that originate on the spinal cord from anterior and posterior roots.
spinal nerve
An expanded portion of a lactiferous duct adjacent to the nipple of a breast.
lactiferous sinus
A mulberry-shaped collection of cells produced through the mitotic divisions of a zygote.
morula
Inflammation of the tonsil(s).
tonsillitis
Hormone that stimulates the production and secretion of glucocorticoids by the zona fasciculata of the adrenal cortex; released by the anterior pituitary in response to CRF.
adrenocorticotropic hormone (ACTH)
Fleshy posterior extension of the hard palate, separating the nasopharynx from the oral cavity.
soft palate
One of the two divisions of the autonomic nervous system; generally responsible for activities that conserve energy and lower the metabolic rate; the “rest and digest” division; also called craniosacral division.
parasympathetic division
The cardiac muscle tissue of the heart.
myocardium
The entry of blood into one of the pleural cavities.
hemothorax
The middle meninx (layer) that encloses cerebrospinal fluid and protects the central nervous system.
arachnoid mater
Nuclei of the cerebrum that are involved in the regulation of somatic motor activity at the subconcious level.
basal nuclei
Tonic muscle contraction in response to stimulation of muscle proprioceptors.
stretch reflex
Axons that carry sensory information to the central nervous system.
afferent fibers
The erosion of a blastocyst into the uterine wall.
implantation
Photoreceptors responsible for vision in dim lighting.
rods
The most important progestin secreted by the corpus luteum following ovulation.
progesterone
One of the three extra-embryonic membranes, composed of an inner layer of endoderm and an outer layer of mesoderm.
yolk sac
The outermost membrane (meninx) of the cranial and spinal meninges.
dura mater
The voiding of urine; micturition.
urination
An auditory ossicle, bound to the tympanic membrane and the incus.
malleus
A terminal lymphatic within an intestinal villus.
lacteal
See pituitary gland.
hypophysis
The division of the autonomic nervous system that is responsible for “fight or flight” reactions; primarily concerned with the elevation of metabolic rate and increased alertness; also called the thoracolumbar division.
sympathetic division
Cyclical changes in the uterine lining that occur in reproductive-age women. Each uterine cycle, which occurs in response to circulating hormones (see ovarian cycle), lasts 21–35 days.
uterine cycle
The crossing point of the optic nerves.
optic chiasm
The joining of two tubes, usually referring to a connection between two peripheral vessels without an intervening capillary bed.
anastomosis/anastomoses
Descending extrapyramidal tracts carrying involuntary motor commands issued by the colliculi.
tectospinal tracts
Margin of the cornea that is overlapped by the sclera.
corneoscleral junction
Region of the adrenal cortex that secretes glucocorticoids.
zona fasciculata
Chemicals that are secreted by one cell and travel through the bloodstream to affect the activities of cells in another part of the body.
hormones
Reproductive organs that produce gametes and sex hormones
gonads
Microfibrils in the cytoplasm of a neuron.
neurofibrils
Epinephrine, norepinephrine, dopamine, and related compounds.
catecholamines
The endocrine (ductless) glands and organs of the body.
endocrine system
The undersurface of the inner cell mass that faces the blastocoele of the early embryo.
hypoblast
The fertilized ovum prior to the start of cleavage.
zygote
Formation of a functional placenta following implantation of a blastocyst in the endometrium.
placentation
Areas in the central nervous system dominated by nerve cell bodies, glial cells, and unmyelinated axons.
gray matter
The middle meninx (layer) that encloses cerebrospinal fluid and protects the central nervous system.
arachnoid mater
Surgical delivery of an infant via an incision through the lower abdominal wall and uterus.
cesarean section
A granulocyte (WBC) with a lobed nucleus and red-staining granules; participates in the immune response and is especially important during allergic reactions.
eosinophils
A rapid, automatic response to a stimulus.
reflex
A bundle of postganglionic sympathetic nerve fibers distributed to effectors in the body wall, skin, and limbs by way of a spinal nerve.
gray ramus communicans
The largest portion of the brain, composed of the cerebral hemispheres; includes the cerebral cortex, the basal nuclei, and the internal capsule.
cerebrum
Fibrous cords that stabilize the position of the AV valves in the heart, preventing backflow during ventricular systole (contraction).
chordae tendineae
Lymphoid organ, site of T cell development and maturation.
thymus
Duct draining one lobe of the mammary gland.
lactiferous duct
A passageway that connects the nasopharynx with the middle ear cavity; also called the Eustachian tube or pharyngotympanic tube.
auditory tube
A mature ovarian follicle containing a large, fluid-filled chamber.
tertiary follicle
Phagocytic agranulocytes (white blood cells) in the circulating blood.
monocytes
The forebrain or cerebrum, including the cerebral hemispheres, the internal capsule, and the cerebral nuclei.
telencephalon
A thickened region of the choroid that encircles the lens of the eye; it includes the ciliary muscle and the ciliary processes that support the ciliary zonule of the lens.
ciliary body
Photoreceptosr responsible for sharp vision and color vision.
cones
Region between a developing oocyte and the surrounding follicular cells of the ovary.
zona pellucida
Enzymes that split peptide bonds and release amino acids.
peptidases
Blood vessels that carry blood away from the heart and toward peripheral capillaries.
arteries
One of the extra-embryonic membranes; surrounds the developing embryo/fetus.
amnion
Fibrous extension of the dura mater and filum terminale; provides longitudinal stabilization to the spinal cord.
coccygeal ligament
A contractile structure made up of smooth muscle that forms the colored portion of the eye.
iris
GH–IH, a hypothalamic regulatory hormone that inhibits GH secretion by the anterior pituitary.
somatostatin
The vein that carries blood to the right atrium from parts of the body that are superior to the heart.
superior vena cava (SVC)
The tracts over which nerve impulses from the retinas are transmitted between the optic chiasm and the thalamus.
optic tracts
A portion of the vestibular apparatus of the internal ear; contains a macula important for providing sensations of gravity and linear acceleration in a vertical dimension.
saccule
One of the extra-embryonic membranes; it provides vascularity to the chorion and is therefore essential to placenta formation; the proximal portion becomes the urinary bladder.
allantois
Transport by way of axoplasm flow toward the cell body (retrograde) or toward the axon terminal (anterograde).
axoplasmic transport
Muscular tubes, lined by transitional epithelium, that carry urine from the renal pelvis to the urinary bladder.
ureters
Reproductive cells (sperm or oocytes) that contain half the normal chromosome complement.
gametes
The main androgen produced by the interstitial endocrine cells of the testes.
testosterone
The medial of the three nuclei of the dorsal column.
gracile nucleus
A broad, flattened process that resembles the external ear; in the ear, the expanded, projecting portion that surrounds the external auditory meatus; also called pinna; in the heart, the externally visible flap formed by the collapse of the outer wall of a relaxed atrium.
auricle
See adrenal gland.
suprarenal gland
The large intestine from the cecum to the rectum.
colon
Groove(s) or furrow(s).
sulcus/sulci
The outer surface of a Schwann cell that encircles an axon in the peripheral nervous system.
neurolemma
Duodenal hormone that stimulates the contraction of the gallbladder and the secretion of enzymes by the exocrine pancreas; also called pancreozymin.
cholecystokinin
Crystalline material similar in mineral composition to bone, but harder and without osteocytes, that covers the exposed surfaces of the teeth.
enamel
To cross over to the opposite side, usually referring to the crossover of the descending tracts of the corticospinal pathway on the ventral surface of the medulla oblongata.
decussate
Region of the brain involved with language comprehension, located in the cortex of the dominant temporal lobe.
Wernicke’s area
Blood vessels between the pulmonary semilunar valve of the right ventricle and the entrance to the left atrium; the blood flow through the lungs.
pulmonary circuit
The beginning of menstrual function.
menarche
Structure within the larynx that consists of the vocal folds and the rima glottidis.
glottis
One of the three main divisions of the nervous system; it is an extensive nerve network in the walls of the digestive tract that initiates and coordinates digestive motility and secretions.
enteric nervous system (ENS)
Descending tracts that carry motor commands from the cerebral cortex to the anterior gray horns of the spinal cord.
corticospinal tracts
Central nervous system neuroglia that maintains cellular organization within gray matter and provides a myelin sheath in areas of white matter.
oligodendrocyte
The superior and inferior colliculi of the mesencephalic tectum (roof) in the brain.
corpora quadrigemina
Conical projection from the inner surface of the duodenum that contains the opening of the duodenal ampulla.
duodenal papilla
Formation of fatty plaques in the walls of arteries, leading to circulatory impairment.
atherosclerosis
The bony roof of the oral cavity, formed by the maxillae and palatine bones.
hard palate
See erythrocytes.
red blood cells (RBCs)
Cells of the blastocyst that will form the body of the embryo.
inner cell mass
An abnormally low blood volume.
hypovolemic
Inflammation of the kidneys.
pyelonephritis
Connective tissue partition that separates adjacent bundles of nerve fibers in a peripheral nerve.
perineurium
Mucous glands in the vaginal walls that secrete into the vestibule; the equivalent of the bulbo-urethral glands of the male.
greater vestibular glands
Passages through the abdominal wall that mark the path of testicular descent and that contain the testicular arteries, veins, and ductus deferens.
inguinal canals
The 15 percent of nephrons whose nephron loops, or loops of Henle, extend into the medulla; these nephrons are responsible for creating the osmotic gradient within the medulla.
juxtamedullary nephrons
Segment of the nephron closest to the collecting tubule and duct; an important site of active secretion.
distal convoluted tubule (DCT)
Lymphoid organ that monitors the composition of lymph.
lymph node
A pair of small cartilages in the larynx.
arytenoid cartilages
The brain minus the cerebrum and cerebellum; midbrain, pons, and medulla oblongata.
brainstem
Sympathetic ganglia located anterior to the spinal column and separate from the sympathetic chain.
collateral ganglia
The passage from the mouth to the pharynx, bounded by the palatal arches, the soft palate, and the uvula.
fauces
Layer of cells lining the ventricles and central canal of the central nervous system.
ependyma
The distal segment of the small intestine.
ileum
A group of specialized secretory cells that is located in a portion of the distal convoluted tubule, adjacent to the glomerulus and the juxtaglomerular cells; a component of the juxtaglomerular complex.
macula densa
Hormone secreted by the alpha cells of the pancreatic islets; increases blood glucose concentrations.
glucagon
Elongate extension of a neuron that conducts an action potential away from the cell body and toward the synaptic terminals
axon
A narrow band of tissue connecting two larger masses.
isthmus
A connective tissue with a gelatinous matrix and an abundance of fibers.
cartilage
Ring of smooth muscle that regulates the passage of chyme from the stomach to the duodenum.
pyloric sphincter
The expanded initial portion of the nephron that surrounds the glomerulus; also called Bowman’s capsule.
glomerular capsule
The cytoplasm that surrounds the nucleus in the cell body of a neuron.
perikaryon
Axons carrying information from the thalamus to the cerebral cortex.
projection fibers
Relative enlargement of the cervical portion of the spinal cord due to the abundance of central nervous system neurons involved with motor control of the arms.
cervical enlargement
Steroid hormones structurally related to cholesterol.
progestins
Blood cell formation and differentiation.
hemopoiesis
A small endocrine gland that secretes steroids and catecholamines and is located superior to each kidney; also called suprarenal gland.
adrenal gland
Steroid sex hormones mainly produced by the interstitial endocrine cells of the testis and manufactured in small quantities by the adrenal cortex in both sexes.
androgens
A localized dilation in the lumen of a canal or passageway.
ampulla
Aggregations of endocrine cells in the pancreas; also called islets of Langerhans.
pancreatic islets
Cytoplasm within an axon.
axoplasm
The elimination of fecal wastes.
defecation
The middle meninx (layer) that encloses cerebrospinal fluid and protects the central nervous system.
arachnoid mater
Meningeal space containing cerebrospinal fluid; the area between the arachnoid mater and the pia mater.
subarachnoid space
The chamber on either side of the nasal septum.
nasal cavity
Collectively, the three layers of smooth muscle in the wall of the urinary bladder.
detrusor
Muscular organ of the female reproductive tract where implantation, placenta formation, and fetal development occur.
uterus
A hypothalamic releasing hormone that causes the secretion of both follicle-stimulating hormone and luteinizing hormone by the anterior lobe of the pituitary gland (adenohypophysis).
gonadotropin-releasing hormone (GnRH)
Corticosteroids produced by the zona glomerulosa of the adrenal cortex; steroids such as aldosterone that affect mineral metabolism.
mineralocorticoids (MCs)
Cranial nerves, which innervate the lateral rectus muscle of the eye.
abducens nerves (N VI)
The gums.
gingivae
An increase in the diameter of arterioles due to the relaxation of smooth muscles in the tunica media; decreases peripheral resistance; may occur in response to local factors, through the action of hormones, or after decreased stimulation of the vasomotor center.
vasodilation
The ribosomes, Golgi apparatus, rough endoplasmic reticulum, and mitochondria of the perikaryon of a typical neuron.
Nissl bodies
Space between the external and internal ear that contains auditory ossicles.
middle ear
The cytoplasm of the oocyte.
ooplasm
An organ of the digestive system with varied and vital functions that include the production of plasma proteins, the excretion of bile, the storage of energy reserves, the detoxification of poisons, and the interconversion of nutrients.
liver
A large fold of the dorsal mesentery of the stomach that hangs in front of the intestines.
greater omentum
The male gonads, sites of gamete production and hormone secretion; also called testicles.
testes
A sheet of mesentery that contains the ligamentum teres, the fibrous remains of the umbilical vein of the fetus.
falciform ligament
An internal passageway that begins at the mouth and ends at the anus.
digestive tract
A tapering, funnel-shaped structure; in the nervous system, refers to the connection between the pituitary gland and the hypothalamus; the infundibulum of the uterine tube is the entrance bounded by fimbriae that receives the oocyte at ovulation.
infundibulum
Lymphoid nodules beneath the epithelium of the small intestine. Also called Peyer’s Patches.
aggregated lymphoid nodules
One complete heartbeat, including atrial and ventricular systole and diastole.
cardiac cycle
Posterior portion of the metencephalon, containing the cerebellar hemispheres; includes the arbor vitae, cerebellar nuclei, and cerebellar cortex.
cerebellum
An abnormally slow heart rate.
bradycardia
The formation of organs during embryological and fetal development.
organogenesis
The distal 15 cm (6 in.) of the digestive tract.
rectum
The attraction of phagocytic cells to the source of abnormal chemicals in tissue fluids.
chemotaxis
Inflammation of the esophagus.
esophagitis
Exocrine secretion of the liver that is stored in the gallbladder and ejected into the duodenum.
bile
Modified smooth muscle cells in the walls of the afferent and efferent arterioles adjacent to the glomerulus and the macula densa.
juxtaglomerular cells
The large, anterior portion of the anterior lobe of the pituitary gland (adenohypophysis).
pars distalis
Prominent folds or ridges of neural cortex on the surfaces of the cerebral hemispheres.
gyri
A tapering, funnel-shaped structure; in the nervous system, refers to the connection between the pituitary gland and the hypothalamus; the infundibulum of the uterine tube is the entrance bounded by fimbriae that receives the oocyte at ovulation.
infundibulum
Later stage in the development of the inner cell mass; it includes the cells that will form the embryo.
blastodisc
A muscular tube extending between the uterus and the vestibule.
vagina
Region of the adrenal cortex that secretes mineralocorticoids.
zona glomerulosa
Abnormally rapid heart rate, usually over 90 beats per minute
tachycardia
An endocrine organ that is located in the sella turcica of the sphenoid bone and is connected to the hypothalamus by the infundibulum; includes the posterior lobe (neurohypophysis) and the anterior lobe (adenohypophysis); also called the hypophysis.
pituitary gland
Circulating transport globulin that binds thyroid hormones.
thyroglobulin
See serous membrane.
serosa
Superficial layer of the blastocyst that will be involved with implantation, hormone production, and placenta formation.
trophoblast
A delicate network of connective tissue fibers that surrounds individual nerve fibers.
endoneurium
The hormone that stimulates functional development of the mammary glands in females; a secretion of the anterior lobe of the pituitary gland (adenohypophysis).
prolactin (PRL)
Basic functional units of the kidneys.
nephrons
Membrane receptors sensitive to epinephrine; stimulation may result in excitation or inhibition of the target cell.
beta (β) receptors
The thalamic nuclei involved in the integration of sensory information prior to projection to the cerebral hemispheres.
pulvinar nuclei
Endocrine cells scattered among the epithelial cells lining the digestive tract.
enteroendocrine cells
An elongated ventricle of the metencephalon (pons and cerebellum) and the myelencephalon (medulla oblongata) of the brain; the roof contains a region of choroid plexus.
fourth ventricle
A porphyrin ring containing a central iron atom that can reversibly bind oxygen molecules; a component of the hemoglobin molecule.
heme
White blood cells containing granules that are visible with the light microscope; includes eosinophils, basophils, and neutrophils; also called granulocytes.
granular leukocytes
The outermost membrane (meninx) of the cranial and spinal meninges.
dura mater
Changes in activity that maintain homeostasis in direct response to changes in the local environment; does not require neural or endocrine control.
autoregulation
Population of T lymphocytes that suppress the immune response.
regulatory T cells
A small pocket in the mesentery that connects the lesser curvature of the stomach to the liver.
lesser omentum
One of the four types of neuroglia in the central nervous system; responsible for maintaining the blood brain barrier by the stimulation of endothelial cells.
astrocytes
Urination.
micturition
The walls of the diencephalon.
thalamus
A hormone secreted by the anterior lobe of the pituitary; stimulates oogenesis (female) and spermatogenesis (male).
follicle-stimulating hormone (FSH)
Coiled tubules where sperm production occurs in the testis
seminiferous tubules
Anterior pituitary hormone that triggers the secretion of thyroid hormones by the thyroid gland.
thyroid-stimulating hormone (TSH)
A component of the male external genitalia; a copulatory organ that surrounds the urethra and introduces semen into the female vagina; the developmental equivalent of the female clitoris.
penis
Hormone secreted by the beta cells of the pancreatic islets; causes a decrease in blood glucose concentrations.
insulin
The process of embryo formation.
embryogenesis
A nonfunctional packet of cytoplasm containing chromosomes eliminated from an oocyte during meiosis.
polar body
Condition resulting from excessive production or inadequate drainage of cerebrospinal fluid.
hydrocephalus
A large, branching neuron of the cerebellar cortex.
Purkinje cell layer
A tubular duct that carries pancreatic juice from the pancreas to the duodenum.
pancreatic duct
Hardening of the arteries.
arteriosclerosis
Surgical opening of the anterior tracheal wall to permit airflow.
tracheostomy
Centers, nuclei, tracts, ganglia, and nerves involved in the unconscious regulation of visceral functions; includes components of the central nervous system and peripheral nervous system.
autonomic nervous system (ANS)
Peritoneal pocket between the anterior surface of the rectum and the posterior surface of the uterus.
recto-uterine pouch
The hormone produced by the activation of angiotensinogen by renin; angiotensin-converting enzyme (ACE) converts angiotensin I into angiotensin II in lung capillaries.
angiotensin I
Stem cells whose divisions produce each of the various populations of blood cells; also called hemocytoblasts.
hematopoietic stem cells
Spiral portion of the bony labyrinth of the internal ear that surrounds the organ of hearing.
cochlea
A dense investment of collagen fibers that surrounds a peripheral nerve.
epineurium
The bony central hub of the cochlea.
modiolus
