Human Body Systems and Biological Processes Flashcards

A comprehensive set of vocabulary flashcards covering human anatomy, physiology, and immunology systems including circulatory, respiratory, digestive, excretory, endocrine, nervous, and immune functions.

Respiratory System (Circulatory Interaction)

Exchanges gases with blood; circulatory system transports oxygen from lungs to tissues and carbon dioxide from tissues to lungs.

Digestive System (Circulatory Interaction)

Absorbs nutrients into the blood; circulatory system distributes these nutrients to cells throughout the body.

Endocrine System (Circulatory Interaction)

Hormones are released into the bloodstream and transported to target organs.

Excretory System (Circulatory Interaction)

Blood carries wastes to kidneys, which filter and remove them as urine.

Reproductive System (Circulatory Interaction)

Delivers hormones and nutrients necessary for reproductive processes and development.

Immune System (Circulatory Interaction)

Transports white blood cells and immune proteins to fight infections.

Thermoregulation (Circulatory Interaction)

Blood redistributes heat by adjusting flow to skin through vasodilation or vasoconstriction.

Pulmonary Circulation Purpose

Moves blood between heart and lungs for gas exchange.

Systemic Circulation Purpose

Moves blood between heart and rest of body to deliver oxygen and nutrients.

Arteries Direction of Flow

Carries blood away from the heart.

Veins Direction of Flow

Carries blood toward the heart.

Capillaries

The site of exchange of gases, nutrients, and wastes between blood and tissues.

Artery Elasticity Importance

Allows arteries to stretch and recoil, maintaining steady blood pressure and flow.

Precapillary Sphincters

Structures that open or close to regulate blood flow into capillary beds based on tissue needs.

Red Blood Cells (RBCs)

Cells that transport oxygen using hemoglobin; characterized by a biconcave shape and no nucleus.

White Blood Cells (WBCs)

Cells with nuclei that defend against infection and foreign invaders.

Platelets

Cell fragments that gather at injury sites to help blood clot and prevent bleeding.

Plasma

The liquid portion of blood that transports nutrients, hormones, proteins, and wastes.

HDL (High-Density Lipoprotein)

Known as good cholesterol; removes cholesterol from blood and transports it to the liver.

LDL (Low-Density Lipoprotein)

Known as bad cholesterol; delivers cholesterol to cells but can deposit it in arteries, forming plaques.

Alveoli

Tiny air sacs where gas exchange occurs.

Diaphragm

A muscle that controls breathing by contracting and flattening during inhalation and relaxing and doming during exhalation.

Hemoglobin

A protein that binds oxygen for transport and helps carry carbon dioxide.

Autotroph

An organism that makes its own food using light or chemical energy.

Heterotroph

An organism that must consume other organisms for energy and nutrients.

Ingestion

The intake of food into the body through eating or feeding.

Digestion

The breakdown of food into smaller molecules that can be absorbed.

Absorption

The movement of digested nutrients into the bloodstream or cells.

Elimination

The removal of undigested waste from the body.

Tube within a Tube

A body plan where the digestive tract is a tube inside the body, allowing one-way flow of food and specialized digestion regions.

Mechanical Digestion

The physical breakdown of food into smaller pieces to increase surface area.

Epiglottis

A flap that prevents food from entering the trachea by closing the airway during swallowing.

Peristalsis

Rhythmic muscle contractions that move food through the digestive tract.

Chyme

A semi-liquid mixture of food and stomach acid.

Pepsin

An enzyme that breaks down proteins and requires an acidic pH to function.

Villi and Microvilli

Structures that increase the surface area of the small intestine for nutrient absorption.

Bile

A substance that emulsifies fats by breaking them into smaller droplets for enzyme action.

Insulin

A hormone that lowers blood glucose levels.

Glucagon

A hormone that raises blood glucose levels.

Kidney Function

Filters blood, removes wastes, and balances water, electrolytes, and pH.

Nephron

The functional unit of the kidney responsible for filtration and reabsorption.

Glomerulus

A part of the nephron that filters blood under high pressure to remove small molecules.

Loop of Henle

A structure in the kidney that creates a salt gradient to concentrate urine and conserve water.

ADH (Antidiuretic Hormone)

A hormone released during dehydration that increases water reabsorption in the collecting duct; high levels produce concentrated urine.

Osmoregulation in Fish

Marine fish lose water while freshwater fish gain water; both use specific mechanisms to balance fluids.

Central Nervous System (CNS)

System consisting of the brain and spinal cord that processes information and makes decisions.

Peripheral Nervous System (PNS)

All nerves outside the CNS that connect the body to the brain and spinal cord.

Autonomic Nervous System

Controls involuntary functions like heart rate, digestion, and breathing; includes sympathetic and parasympathetic divisions.

Sympathetic Division

Triggers the 'fight or flight' response, increasing heart rate and slowing digestion.

Parasympathetic Division

Triggers 'rest and digest' functions, slowing heart rate and stimulating digestion.

Afferent Division

Sensory signals traveling from the body to the CNS.

Efferent Division

Motor signals traveling from the CNS to the body.

Neurons

Cells that transmit electrical signals throughout the body.

Glial Cells

Cells that support, protect, and nourish neurons.

Myelin Sheath

A layer that insulates the axon and speeds up signal transmission.

Action Potential

A rapid change in membrane potential used to send signals along a neuron.

Depolarization

Process where $Na^+$ ions enter the cell, making the inside more positive.

Repolarization

Process where $K^+$ ions exit the cell, restoring a negative charge.

Frontal Lobe

Brain region responsible for decision-making, planning, voluntary movement, and personality.

Pathogen

A microorganism or agent capable of causing disease under certain conditions.

Innate Immune System

A fast, non-specific first line of defense present at birth.

Adaptive Immune System

A slower, highly specific defense that develops memory after exposure.

Neutrophil

An innate granulocyte that rapidly phagocytoses bacteria.

Macrophage

An innate phagocyte that engulfs pathogens and debris in tissues.

B Cell

An adaptive immune cell that produces antibodies.

T Cell

An adaptive immune cell that kills infected cells or regulates the immune response.

Antigen

A whole molecule recognized by the immune system.

Epitope

The specific region of an antigen recognized by the adaptive immune system.