Urinary and Lymphatic Systems

Comprehensive vocabulary flashcards covering the anatomical structures, physiological functions, fluid pathways, and immune mechanisms of the urinary and lymphatic systems.

Kidneys

Paired retroperitoneal organs extending from T12 to L3 along the posterior abdominal wall that filter blood, remove metabolic wastes, regulate water, electrolytes, pH, and blood pressure, and produce hormones.

Retroperitoneal

An anatomical position located behind the parietal peritoneum, meaning the organs (such as the kidneys) are not encapsulated by the parietal peritoneum.

Renin

A hormone produced by the kidneys that is involved in blood pressure regulation.

Erythropoietin (EPO)

A hormone produced by the kidneys that stimulates red blood cell production.

Nephron

The functional unit of the kidney responsible for the three major processes of urine formation: filtration, reabsorption, and secretion.

Glomerulus

A network of capillaries located within the renal corpuscle that serves as the specific site of blood filtration in the nephron.

Filtration

The initial step of urine formation at the renal corpuscle where water and small dissolved solutes pass from the blood into the nephron, while blood cells and proteins remain in the blood.

Reabsorption

The renal process by which useful substances such as water, glucose, amino acids, and sodium are reclaimed from the tubular fluid back into the blood.

Secretion

The renal process that moves specific substances, such as hydrogen ions, potassium ions, metabolic wastes, and certain drugs, from the blood directly into the nephron.

Ureters

Muscular tubes that transport urine from the kidneys to the urinary bladder primarily through peristaltic contractions of smooth muscle.

Peristalsis

Rhythmic contractions of smooth muscle that propel urine through the ureters toward the urinary bladder.

Urinary Bladder

A hollow, muscular organ that serves primarily as a temporary storage reservoir for urine.

Detrusor Muscle

The smooth muscle wall of the urinary bladder that contracts during micturition to increase bladder pressure and expel urine.

Trigone

A smooth, triangular region on the floor of the urinary bladder outlined by three openings: the right ureteral opening, the left ureteral opening, and the internal urethral opening.

Internal Urethral Sphincter

An involuntary smooth muscle sphincter located at the bladder neck that prevents urine from exiting when urination is not taking place.

External Urethral Sphincter

A voluntary skeletal muscle sphincter that provides conscious control over urination.

Urethra

The conduit that carries urine from the urinary bladder to the outside of the body.

Cystitis

Inflammation of the urinary bladder, commonly associated with a lower urinary tract infection, manifesting with dysuria, urgency, frequency, and suprapubic discomfort.

Lacteals

Specialized lymphatic capillaries located in the small intestine that absorb dietary fats.

Lymphatic Capillaries

Microscopic closed-ended vessels that collect excess interstitial tissue fluid and serve as the starting point of the lymphatic drainage pathway.

Right Lymphatic Duct

A major lymphatic duct that drains lymph from the right upper body, specifically the right side of the head and neck, right upper limb, and right side of the thorax.

Thoracic Duct

A major lymphatic duct that drains lymph from most of the body, including both lower limbs, the abdomen, the left side of the thorax, the left upper limb, and the left side of the head and neck.

Lymph Nodes

Small encapsulated organs arranged along lymphatic vessels that filter lymph and house immune cells to detect and respond to pathogens.

Spleen

A secondary lymphatic organ that filters blood, removes old or damaged red blood cells, and participates in immune responses.

Thymus

A primary lymphatic organ essential for the maturation and differentiation of T lymphocytes.

B Lymphocytes (B cells)

Immune cells responsible for antibody-mediated (humoral) immunity that can differentiate into plasma cells that produce antibodies.

T Lymphocytes (T cells)

Immune cells that mature in the thymus and mediate cellular and regulatory adaptive immunity.

Active Immunity

Acquired immunity produced by an individual's own immune response following exposure to an antigen (via infection or vaccination), typically developing slower but creating long-lasting immune memory.

Passive Immunity

Temporary immunity conferred by receiving ready-made antibodies from another source (such as maternal transfer or immunoglobulin administration), providing immediate protection without establishing long-term memory.

Anaphylaxis

A severe, rapid, life-threatening systemic hypersensitivity reaction that can cause airway swelling, wheezing, hypotension, hives, and difficulty breathing.

First Line of Defense

Nonspecific physical and chemical surface barriers—such as skin, mucous membranes, mucus, tears, saliva, and stomach acid—that prevent pathogens from entering the body.

Second Line of Defense

Innate internal defense mechanisms that rapidly respond after pathogens penetrate surface barriers, including inflammation, phagocytic cells, fever, natural killer cells, and complement proteins.

Third Line of Defense

The adaptive immune system, consisting of antigen-specific B lymphocytes and T lymphocytes that generate targeted immune responses and memory.