BIO20: Human Systems

Nutrients

Substances essential for growth, development, and maintenance of life, found in food and necessary for the functioning of the body.

Enzymes

Proteins that act as biological catalysts, speeding up chemical reactions in living organisms without being consumed in the process.

Digestive System

The system in the body responsible for breaking down food into nutrients that can be absorbed and used by cells for energy and growth.

Macromolecules

Large molecules essential for life, including carbohydrates, lipids, proteins, and nucleic acids.

Dehydration Synthesis

An anabolic reaction where two molecules are joined together to form a larger molecule, with the release of a water molecule.

Hydrolysis

A catabolic reaction where a larger molecule is broken down into smaller molecules by the addition of a water molecule.

Nucleic Acids

Biomolecules, including DNA and RNA, that carry genetic information and are essential for the functioning and development of all living organisms.

Carbohydrates

Organic compounds made of carbon, hydrogen, and oxygen, serving as a primary source of energy for the body.

Lipids

Organic compounds that are insoluble in water, including fats and oils, important for energy storage, insulation, and cell membrane structure.

Proteins

Complex molecules made up of amino acids, essential for the structure, function, and regulation of the body's tissues and organs.

Enzymes

Proteins that act as catalysts to speed up chemical reactions in the body, facilitating processes like digestion and metabolism.

Digestive Tract

The series of organs through which food passes, including the mouth, esophagus, stomach, small intestine, and large intestine, where digestion and absorption of nutrients occur.

Pancreas

An accessory organ located at the duodenum that secretes sodium bicarbonate to neutralize acidic stomach chyme, changes pH to around 8, and produces enzymes like trypsin, chymotrypsin, pancreatic amylase, and lipase.

Liver

A vital organ at the duodenum that functions as a chemistry lab, producing over 1000 enzymes and proteins, involved in digestion, storage of carbohydrates, metabolism of proteins and lipids, breakdown and excretion of waste products, and secretion of bile to emulsify fats.

Gall bladder

An organ that stores bile produced by the liver and releases it into the duodenum during digestion.

Large Intestine

Part of the digestive system responsible for absorbing water and salts, concentrating and eliminating indigestible waste, and relying on intestinal bacteria to further break down indigestible food.

Circulatory System

The transport system of the body consisting of the heart, blood vessels, and blood, with primary functions including transportation of nutrients, gases, and waste; maintenance of homeostasis; and protection against blood loss and infections.

Heart

A muscular organ that pumps blood throughout the body, with chambers including the atria and ventricles, separated into left and right sides by the septum, and valves like the atrioventricular and semilunar valves to prevent backflow of blood.

Blood Flow Through the Heart

The pathway of blood flow starting with deoxygenated blood entering the right atrium, passing through the tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary arteries to the lungs, returning as oxygenated blood through the pulmonary veins to the left atrium, left ventricle, aortic semilunar valve, and aorta to the body.

Blood Vessels

Arteries carry blood away from the heart, arterioles are small arteries joining larger ones to capillaries, and capillaries are the smallest blood vessels allowing material exchange due to their thin walls and high surface area.

Venules

Small veins connecting capillaries to veins.

Veins

Blood vessels that carry blood towards the heart, carrying deoxygenated blood except for pulmonary veins, with thin walls compared to arteries.

Sinoatrial (SA) node

Bundle of specialized muscle tissue in the right atrium wall, acting as the body's pacemaker.

Atrioventricular (AV) node

Node that transmits signals from the SA node through specialized fibers, leading to ventricular contractions.

Electrocardiogram (ECG)

Device that tracks the electrical signals traveling through the heart nodes.

Blood Pressure

The pressure exerted by blood against vessel walls, measured in mmHg.

Cardiac Output

Volume of blood pumped per minute, calculated by heart rate multiplied by stroke volume.

Hemophilia

A disorder characterized by insufficient clotting proteins in the blood.

Leukemia

Cancer of white blood cells, which can be myeloid or lymphoid.

Plasma

The fluid portion of blood containing cells, proteins, gases, and nutrients.

Red Blood Cells (Erythrocytes)

Blood cells produced in the bone marrow, lacking nuclei and containing hemoglobin to carry oxygen.

White Blood Cells (Leukocytes)

Cells involved in immune defense, including granulocytes, monocytes, and lymphocytes.

Platelets

Fragments of broken bone marrow cells that aid in blood clotting.

Lymphatic System

Network of vessels, glands, and nodes that help maintain fluid balance and immunity in the body.

Innate Immune System

The body's non-specific defense system with pre-determined mechanisms applied to all pathogens and lacking memory.

Cytotoxicity

The process of cell-poisoning involving the release of granules containing antimicrobial and cytolytic substances by cells like neutrophils, basophils, eosinophils, and natural killer cells.

Phagocytosis

The mechanism where cells like neutrophils, monocytes/microphages, and dendritic cells engulf pathogens to eliminate them.

Antigen presentation

The process of displaying antigens on cell surfaces to be recognized by antigen receptors on lymphocytes, aiding in immune response.

Inflammatory response

The reaction to injury or pathogens involving chemical cascades, increased blood flow, leukocyte migration, and swelling.

Adaptive Immune System

Pathogen-specific defense system recruiting lymphocytes with tailored mechanisms, memory, and the ability to differentiate between self and non-self antigens.

T Lymphocytes (T cells)

Essential immune cells with subsets like cytotoxic T cells, helper T cells, and regulatory T cells, playing diverse roles in immunity.

B Lymphocytes (B cells)

Immune cells produced in the bone marrow, activated by antigens, and capable of producing antibodies for immune response.

Antibody-mediated immunity

Immune defense involving antibodies binding to specific antigens on pathogens, marking them for destruction by other immune cells.

Blood Types

Classification of blood based on the presence or absence of certain antigens on the surface of red blood cells.

Antibodies

Proteins produced by the immune system in response to foreign substances (antigens) in the body.

Allergies

Exaggerated immune responses to harmless substances.

Hygiene Hypothesis

Theory suggesting that increased cleanliness and reduced exposure to pathogens may lead to an underdeveloped immune system and increased risk of allergies.

Transplantation

The process of transferring cells, tissues, or organs from one individual to another.

Cancer

Disease characterized by the uncontrolled growth and spread of abnormal cells in the body.

Respiratory System

The organ system responsible for breathing and gas exchange in the body.

Inspiration

The process of inhaling air into the lungs.

Expiration

The process of exhaling air out of the lungs.

External Respiration

Exchange of oxygen and carbon dioxide between the air and blood.

Internal Respiration

Exchange of oxygen and carbon dioxide between blood and tissue cells.

Cellular Respiration

Chemical reactions inside cells that release energy for cellular functions.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Diaphragm

Sheet of muscle separating the thoracic and abdominal cavities involved in breathing.

Pleural Membranes

Thin layers of tissue that cover the lungs and line the chest cavity.

Tidal Volume

Amount of air moved in and out with each breath.

Vital Capacity

Maximum volume of air that can be moved in and out during a single breath.

Residual Volume

Amount of air remaining in the lungs after the deepest possible exhalation.

Tonsillitis

Infection of the tonsils located in the pharynx, often viral in nature and can lead to breathing difficulties.

Bronchitis

Inflammation of the bronchi resulting in mucus buildup that is expelled through coughing.

Pneumonia

Inflammation of the alveoli leading to fluid accumulation, impacting gas exchange and tissue oxygen levels.

Pleurisy

Swelling and irritation of the pleura, the membrane surrounding the lungs.

Emphysema

Condition where the walls of the alveoli break down, reducing elasticity and gas exchange capacity.

Cystic Fibrosis

Genetic disorder affecting the cells lining the lungs' passageways, leading to disrupted function.

Asthma

Chronic obstructive lung disease affecting bronchi and bronchioles, resulting in decreased airflow.

Lung Cancer

Uncontrolled growth of abnormal cells in the lungs, leading to invasive tumors.

Tubular Reabsorption

The process of reabsorbing substances like water and ions from the filtrate in the renal tubules back into the bloodstream.

Water Reabsorption

The process of returning water from the filtrate in the renal tubules back into the bloodstream.

Osmosis

The movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

Aldosterone

A hormone that regulates sodium balance by promoting the reabsorption of sodium in the distal tubule and collecting duct of the kidneys.

Antidiuretic Hormone (ADH)

A hormone that regulates water reabsorption by increasing the permeability of the distal tubule and collecting duct in the kidneys.

Acid-base Buffer System

A system in the body that helps maintain the pH balance of body fluids by regulating the concentration of hydrogen ions.

Urinary Tract Infections (UTI)

Bacterial infections that can occur in any part of the urinary tract, leading to symptoms such as pain during urination and frequent urination.

Diabetes Mellitus

A group of metabolic disorders characterized by high blood sugar levels, which can lead to increased sugar and water excretion in the urine.

Hemodialysis

A medical procedure that uses a machine to filter waste products from the blood when the kidneys are unable to perform this function adequately.

Aerobic cellular respiration

Process occurring in mitochondria that produces the majority of ATP by combining glucose, oxygen, and ADP to form ATP, water, and carbon dioxide. Muscle cells contain myoglobin to capture and store oxygen for mitochondria.

Fermentation (anaerobic)

Process that supplies ATP for a limited time when oxygen is depleted, converting glucose and ADP into ATP and lactate, leading to the accumulation of lactic acid and muscle fatigue.

Muscular atrophy

Decrease in muscle size due to lack of use, which can be caused by various factors like spinal cord injury, nerve damage, or general inactivity.

Muscular hypertrophy

Increase in muscle size and strength induced by exercise, involving the growth of muscle fibers through the overload and adapt principle.

Slow-twitch muscle fibers

Muscle fibers that primarily produce energy aerobically, contract slowly, have high endurance, and contain abundant myoglobin and mitochondria for aerobic respiration.

Fast-twitch muscle fibers

Muscle fibers that primarily produce energy anaerobically, are rich in glycogen for rapid ATP regeneration, fatigue easily, and have fewer mitochondria and less vascularization.