Comprehensive Review of Blood, Human Development, Endocrine System, and Immunity

Vocabulary flashcards covering key definitions, hormones, cell types, anatomical structures, and physiological processes across blood, development, endocrine systems, and immunology.

Erythrocytes

Biconcave disk-shaped formed elements that are the most numerous cells in blood and transport most of the oxygen as well as some carbon dioxide.

Hemoglobin

The iron-containing protein in red blood cells; each molecule can bind with up to $4$ oxygen molecules.

Erythropoietin

A hormone produced by the kidneys in response to low blood oxygen levels that stimulates red blood cell production.

Bilirubin

A breakdown product of hemoglobin whose excessive accumulation in circulation and interstitial spaces causes jaundice.

Diapedesis

The process by which white blood cells leave the circulatory system by squeezing between endothelial cells to enter tissues.

Neutrophils

Phagocytic white blood cells with tri-lobed nuclei that constitute the largest percentage of all leukocytes.

Monocytes

The largest leukocytes in circulation that increase in number during chronic infections and differentiate into macrophages.

B Cells

Lymphocytes stimulated by helper T cells that differentiate into plasma cells to produce antibodies.

Plasmin

An enzyme involved in fibrinolysis that dissolves blood clots by breaking down fibrin.

Extrinsic Clotting Pathway

A blood clotting pathway initiated by the release of thromboplastin (tissue factor), requiring $Ca^{2+}$ and leading to prothrombinase production.

Tissue Plasminogen Activator (t-PA)

A clot-dissolving chemical administered to break down thrombi causing blockage in coronary arteries.

RhoGAM

An injection administered to Rh-negative mothers to prevent them from producing anti-Rh antibodies against an Rh-positive fetus.

Hemocytoblasts

Stem cells located in the red bone marrow that give rise to all formed elements of the blood.

Clinical Age

The age of an unborn child calculated from the last menstrual period, which is $14$ days more than the postovulatory age.

Syncytiotrophoblast

Multinucleated embryonic cells that invade the uterine endometrium and form lacunae during implantation.

Ductus Arteriosus

A short arterial vessel connecting the pulmonary trunk to the aorta in the fetus, which closes shortly after birth.

Meconium

A greenish discharge passed through the anus by a newborn baby shortly after birth.

Colostrum

The initial secretion from the mammary glands produced during the first few days post-partum, which contains antibodies.

Prolactin

An anterior pituitary hormone that stimulates milk production in the mammary glands.

Oxytocin

A posterior pituitary hormone that stimulates milk letdown during lactation and causes uterine smooth muscle contractions.

Fast Block to Polyspermy

The initial rapid depolarization of the oocyte plasma membrane triggered by the penetration of the first sperm cell.

Atherosclerosis

An accumulation of soft lipid, cholesterol, and calcium deposits within the tunica intima of medium and large arteries.

Adenohypophysis

The anterior lobe of the pituitary gland that synthesizes and secretes tropic and direct hormones.

Diabetes Insipidus

A disorder caused by a lack of ADH secretion, resulting in extreme thirst, dehydration, and high volumes of dilute urine.

Acromegaly

A condition characterized by bone and tissue enlargement in adults caused by the hypersecretion of growth hormone.

Calcitonin

A hormone secreted by the thyroid gland in response to elevated blood calcium levels to lower systemic calcium.

Parathyroid Hormone (PTH)

A hormone that elevates blood calcium levels by increasing osteoclast activity, renal calcium reabsorption, and intestinal absorption.

Aldosterone

A mineralocorticoid hormone secreted by the adrenal cortex that increases sodium concentration in the blood.

Cortisol

A glucocorticoid hormone secreted by the adrenal cortex that promotes gluconeogenesis to maintain blood glucose levels.

Cushing's Syndrome

A metabolic disorder caused by hypersecretion of cortisol, marked by muscle wasting, a buffalo hump, moon face, and impaired wound healing.

Glucagon

A pancreatic hormone targeting the liver to stimulate glycogen breakdown and increase blood glucose levels.

Pheromones

Chemical signals secreted into the external environment that modify the behavior and physiology of other individuals.

Neurohormones

Intercellular chemical messengers produced and released by neurons that travel through the bloodstream to function like hormones.

Steroids

Lipid-soluble chemical signals derived from cholesterol, including estrogen, progesterone, testosterone, and cortisol.

Acute Hormone Regulation

A pattern of hormone release where secretion rapidly increases in response to a stimulus and decreases quickly once the stimulus ends.

Conjugation

A liver process that attaches water-soluble molecules like sulfate or glucuronic acid to lipid-soluble hormones to facilitate elimination.

Down-regulation

A decrease in target cell responsiveness caused by a reduction in receptor number via internal degradation, phagocytosis, or reduced synthesis.

Lymph Nodes

Encapsulated lymphatic organs containing reticular fibers and sinuses that filter lymph and serve as sites for lymphocyte proliferation.

Spleen

A secondary lymphatic organ containing red and white pulp that acts as a blood reservoir and destroys worn-out red blood cells.

Complement System

A group of plasma proteins activated in a cascade series that promotes inflammation, phagocytosis, and cell lysis.

Interferons

Antiviral proteins released by infected cells that prevent viral replication in neighboring cells by inhibiting nucleic acid and protein synthesis.

Macrophages

Large phagocytic tissue cells derived from circulating monocytes, including specialized forms like dust cells, microglia, and Kupffer cells.

Cytokines

Secreted signaling proteins that regulate immune responses by promoting inflammation, activating macrophages, and promoting cell lysis.

IgG

The most abundant serum antibody ($80$ to $85$\%) that crosses the placenta and is responsible for Rh hemolytic reactions.