Human Biology Modules 11-15 Study Guide

A comprehensive collection of vocabulary flashcards covering Modules 11 through 15, including the urinary, skeletal, muscular, respiratory, and reproductive systems, as well as biotechnology basics.

Nephron

The functional unit of the kidney, with approximately 1 million per kidney, responsible for filtering blood and forming urine.

Renal Corpuscle

The part of the nephron composed of the glomerulus and Bowman's capsule where filtration occurs.

Glomerular Filtration Rate (GFR)

An indicator of kidney function based on the rate at which blood is filtered into the Bowman's capsule.

Erythropoietin (EPO)

A hormone secreted by the kidneys that stimulates red blood cell production in the bone marrow.

Renin

An enzyme/hormone secreted by the kidneys that helps regulate blood pressure.

Proximal Convoluted Tubule (PCT)

The part of the nephron that reclaims almost everything useful, including glucose, amino acids, salts ($Na^+$, $Cl^-$), and water.

Loop of Henle

A U-shaped tube in the nephron consisting of a descending limb where water leaves and an ascending limb where $Na^+$ and $Cl^-$ leave to create a medullary concentration gradient.

Antidiuretic Hormone (ADH)

A hormone that increases water reabsorption in the collecting duct, leading to decreased urine volume.

Uremia

A condition involving the buildup of toxins in the blood due to kidney failure.

Hemodialysis

A treatment for kidney failure involving an artificial blood filtration machine.

Diaphysis

The long, main shaft portion of a long bone.

Epiphysis

The ends of a long bone, which contain spongy bone and red bone marrow.

Osteon

The basic structural unit of compact bone.

Osteocytes

Mature bone cells that reside in spaces called lacunae and maintain the bone matrix.

Osteoblasts

Bone cells responsible for building or depositing new bone tissue.

Osteoclasts

Bone cells responsible for breaking down or resorbing bone tissue.

Axial Skeleton

The division of the skeleton consisting of the skull, vertebral column, and rib cage.

Appendicular Skeleton

The division of the skeleton consisting of the limbs and girdles.

Parathyroid Hormone (PTH)

A hormone that increases blood calcium levels by stimulating bone breakdown.

Calcitonin

A hormone that decreases blood calcium levels by promoting its storage in bones.

Sarcomere

The functional unit of skeletal muscle contraction, extending from one Z line to the next.

Sarcolemma

The specialized plasma membrane of a muscle cell.

Sarcoplasmic Reticulum

A specialized smooth endoplasmic reticulum in muscle cells that stores calcium ions ($Ca^{2+}$).

Myoglobin

An oxygen-storing protein found in muscle tissue.

Sliding Filament Theory

The model of muscle contraction where actin filaments slide past myosin filaments, shortening the sarcomere without the filaments themselves changing length.

Acetylcholine (ACh)

The neurotransmitter released by motor neurons at the neuromuscular junction to trigger muscle contraction.

Agonist

The primary muscle responsible for a specific contraction or movement.

Antagonist

The muscle that opposes the action of the agonist.

Synergist

A muscle that assists the agonist in performing a movement.

Creatine Phosphate System

An energy system in muscles that provides very fast, short-duration bursts of ATP.

Larynx

The cartilaginous structure between the pharynx and trachea, also known as the voice box, which contains the vocal cords.

Epiglottis

A flap of tissue that closes the airway during swallowing to prevent food from entering the larynx.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs, providing a large surface area of approximately $50-70\,m^2$.

Surfactant

A substance produced in the alveoli that reduces surface tension to prevent them from collapsing.

Boyle's Law

The physical law stating that pressure is inversely related to volume, explaining how air moves in and out of the lungs.

Tidal Volume

The volume of air inhaled or exhaled during a normal, relaxed breath.

Vital Capacity

The maximum volume of air that can be exhaled after a maximum inhalation.

External Respiration

The exchange of gases specifically between the alveoli of the lungs and the blood in the pulmonary capillaries.

Internal Respiration

The exchange of gases between the blood in systemic capillaries and the body cells.

Carbonic Anhydrase

An enzyme that speeds up the reaction between $CO_2$ and water to form carbonic acid.

Spermatogenesis

The process of sperm production occurring within the seminiferous tubules of the testes.

Leydig Cells

Cells in the testes that produce the hormone testosterone.

Sertoli Cells

Cells in the testes that support sperm production, stimulated by FSH.

Ovarian Cycle

The monthly series of events in the ovaries, including the follicular phase, ovulation (triggered by an LH surge), and the luteal phase.

Corpus Luteum

The structure formed from a ruptured follicle after ovulation that secretes progesterone to maintain the uterine lining.

Human Chorionic Gonadotropin (hCG)

A hormone produced by the placenta that maintains the corpus luteum during early pregnancy.

SRY Gene

A gene located on the Y chromosome that triggers male developmental pathways during fertilization.

Telomeres

Chromosomal end sequences that shorten with each cell division, acting as a limit on the lifespan of the cell.

Semiconservative Replication

The mechanism of DNA replication where each new double helix consists of one original parent strand and one newly synthesized strand.

Helicase

The enzyme responsible for breaking hydrogen bonds to unwind the DNA double helix into a replication fork.

DNA Polymerase

The enzyme that adds nucleotides to a growing DNA strand in the 5' to 3' direction.

Okazaki Fragments

Short DNA segments synthesized on the lagging strand that are later joined together by ligase.

Central Dogma

The biological principle that genetic information flows from DNA to RNA (transcription) and then to protein (translation).

Codon

A triplet of mRNA bases that codes for a specific amino acid, such as AUG which serves as the START codon.

Polymerase Chain Reaction (PCR)

A biotechnology technique used to amplify specific segments of DNA.

CRISPR-Cas9

A gene-editing tool used for precise modification of DNA sequences.