A&P II Practice Flashcards: Histology, Blood, Cardiovascular & Endocrine

Comprehensive vocabulary flashcards covering histology, blood composition, heart physiology, and the endocrine system based on A&P II lecture materials.

Epithelial Tissue

Cells packed tightly, covers surfaces, lines cavities, and forms glands; shows polarity with apical and basal surfaces.

Connective Tissue

Cells scattered in an extracellular matrix (ECM) consisting of fibers and ground substance; functions in support, binding, and protection.

Pseudostratified Ciliated Columnar Epithelium

Tissue that looks multilayered because nuclei sit at different heights, but every cell touches the basement membrane; commonly found in the trachea.

Transitional Epithelium

Stratified tissue with rounded dome-shaped surface cells that can stretch and flatten; found in the urinary bladder and ureters.

Mesenchyme

Embryonic connective tissue with star-shaped cells and gel-like ground substance that gives rise to all other connective tissues.

Intercalated Discs

Specialized junctions in cardiac muscle containing desmosomes to transfer force and gap junctions to propagate action potentials.

Albumins

The most abundant plasma proteins (60%) that contribute to plasma osmotic pressure and transport fatty acids and steroids.

Erythropoiesis

The process of red blood cell formation, which occurs in red bone marrow and is stimulated by the hormone EPO.

Hematocrit

The percentage of formed elements in whole blood; averages $45\%$ for males and $40\%$ for females.

Hemoglobin

A protein with 4 globular subunits (2 alpha, 2 beta), each containing a heme group with iron that binds oxygen.

Neutrophils

Granulocytes that make up $50-70\%$ of WBCs; first responders against bacteria that use phagocytosis and form pus.

Hemostasis

The process of stopping blood loss, consisting of the vascular phase, platelet phase, and coagulation phase.

Thrombin

An enzyme that converts soluble fibrinogen into insoluble fibrin during the coagulation phase of hemostasis.

Agglutinogen

An antigen found on the surface of red blood cells used to determine blood type.

Agglutinin

An antibody found in the blood plasma that reacts against specific A or B antigens.

Myocardium

The thick middle layer of the heart wall composed of cardiac muscle tissue.

Bicuspid Valve

Also known as the mitral valve; the AV valve located between the left atrium and the left ventricle.

SSA node

The primary pacemaker of the heart, normally generating pulses at a rate of $80-100$ pulses per minute.

P wave

The feature of an ECG that represents atrial depolarization.

QRS complex

The feature of an ECG that represents ventricular depolarization; atrial repolarization is hidden here.

Stroke Volume (SV)

The volume of blood ejected from a ventricle in one beat; calculated as $SV = EDV - ESV$.

Cardiac Output (CO)

The volume of blood pumped by a ventricle in one minute; calculated as $CO = HR \times SV$.

Frank-Starling Law of the Heart

The principle stating that an increase in EDV (preload) causes a stronger contraction and increased stroke volume (more in = more out).

Afterload

The amount of pressure or tension the ventricles must overcome to open the semilunar valves.

Second Messenger

Intracellular molecules like $cAMP$, $cGMP$, $Ca^{2+}$, $IP_3$, or $DAG$ that translate a hormone's signal into a cellular response.

Hypophyseal Portal System

A network of blood vessels that carries regulatory hormones from the hypothalamus directly to the anterior pituitary.

Antidiuretic Hormone (ADH)

A hormone made in the hypothalamus and released by the posterior pituitary that causes the kidneys to retain water.

Calcitonin

A peptide hormone produced by thyroid C cells that decreases blood calcium levels.

Parathyroid Hormone (PTH)

A hormone from the parathyroid chief cells that increases blood calcium by stimulating osteoclasts and renal reabsorption.

Zona Glomerulosa

The outermost layer of the adrenal cortex that produces mineralocorticoids, primarily aldosterone.

Zona Fasciculata

The middle and largest layer of the adrenal cortex that produces glucocorticoids, primarily cortisol.

Type 1 Diabetes Mellitus

A condition characterized by inadequate insulin production by pancreatic beta cells, typically occurring in children.

Type 2 Diabetes Mellitus

A condition characterized by insulin resistance, where target tissues do not respond well to insulin; often associated with obesity.

General Adaptation Syndrome (GAS)

The body's three-phase stress response: alarm phase (epinephrine), resistance phase (glucocorticoids), and exhaustion phase.

Addison Disease

A disorder caused by hyposecretion of glucocorticoids and aldosterone due to the destruction of the adrenal cortex.

Cushing Syndrome

A disorder caused by hypersecretion of glucocorticoids, characterized by fat redistribution and poor wound healing.

Acromegaly

A condition caused by the hypersecretion of growth hormone (GH) in adulthood, resulting in thickened skin and facial features.

Melatonin

A hormone produced by the pineal gland during darkness that sets circadian rhythms and promotes sleep.