Human Body Systems: Anatomy and Physiology Lecture Outlines

A complete set of vocabulary flashcards covering key organs, tissues, structures, and physiological processes across the human digestive, urinary, cardiovascular, respiratory, endocrine, lymphatic, integumentary, skeletal, muscular, and nervous systems.

Digestive System

Body system whose primary functions are ingestion, mechanical and chemical digestion, absorption, and elimination.

Esophagus

A muscular tube that connects the pharynx to the stomach and moves food downward using peristalsis.

Stomach

Digestive organ that conducts mechanical and chemical digestion in an acidic environment ($\text{HCl}$), using pepsin for protein breakdown, and turns food into chyme.

Small Intestine

Digestive organ that continues mechanical digestion and absorbs broken-down nutrients into the bloodstream through villi and microvilli.

Gallbladder

An accessory digestive organ that stores excess bile.

Liver

An accessory digestive organ that produces bile for fat emulsification.

Large Intestine (Colon)

Digestive organ that absorbs water, moves undigested solids, and stores feces in the rectum.

Excretory System

Body system that eliminates waste products to maintain homeostasis; composed of the skin (perspiration), lungs (exhalation), and urinary system.

Kidneys

Urinary organs that form urine, reabsorb essential substances such as electrolytes and sugars, and filter about $1700\,\text{liters}$ of blood daily; divided into cortex, medulla, and pelvis.

Urinary Bladder

Urinary organ that stores urine ($300-400\,\text{mL}$ before emptying).

Urethra

Tube that carries urine from the bladder to the outside of the body, varying in length between genders.

Cardiovascular System

Body system that circulates blood to transport oxygen, nutrients, and waste, and moves immune cells and hormones throughout the body.

Heart

Muscular organ that pumps blood through the body, consisting of four chambers: $2$ atria and $2$ ventricles.

Arteries

Vessels that carry blood away from the heart, characterized by thick, muscular walls and elastic fibers to handle blood pressure.

Veins

Vessels that return blood to the heart, featuring thin walls and internal valves to prevent backflow.

Capillaries

Microscopic blood vessels that are one cell thick, allowing material exchange of oxygen, $\text{CO}_2$, and nutrients between blood and tissues.

Red Blood Cells

Blood components that carry oxygen via hemoglobin.

White Blood Cells

Blood cells that form part of the immune system to fight infection.

Plasma

The liquid portion of blood containing nutrients, hormones, and proteins.

Platelets

Formed elements in the blood that assist in blood clotting.

Systemic Loop

The cardiovascular pathway circulating blood between the heart and the rest of the body.

Pulmonary Loop

The cardiovascular pathway circulating blood between the heart and the lungs.

Cardiovascular Blood Flow Pathway

The flow of blood through the body: inferior/superior vena cava, right atrium, tricuspid valve, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, bicuspid valve, left ventricle, aorta, and body.

Pharynx

An anatomical structure that serves as a common crossroad for air and food pathways.

Larynx

The voice box containing vocal cords for sound production.

Trachea

The windpipe, supported by cartilage rings to maintain an open airway.

Bronchioles

Fine branching tubes leading from the bronchi into the lungs, covered with cilia and mucus to trap particles.

Alveoli

Air sacs surrounded by capillaries where gas exchange occurs: oxygen diffuses into the blood and carbon dioxide diffuses out.

Inhalation

Active breathing phase during which the diaphragm contracts down and the chest cavity expands.

Exhalation

Breathing phase during which the diaphragm relaxes upward and air is pushed out.

Hormone

Chemical substances that act like messenger molecules in the body.

Gland

An organ that produces and secretes particular hormones directly into the bloodstream.

Hypothalamus

Endocrine and neural structure that regulates blood pressure, body temperature, and heart rate.

Pineal Gland

An endocrine gland that releases melatonin to regulate sleep patterns.

Pituitary Gland

The master gland of the endocrine system that controls other endocrine glands and regulates functions such as temperature and metabolism.

Thyroid Gland

An endocrine gland that regulates metabolism and releases $\text{T}_3$ and $\text{T}_4$ hormones.

Parathyroid Gland

Endocrine glands that control calcium and phosphate levels in the body.

Thymus Gland

A gland active in early life that stimulates T cells, promotes growth hormone production, and produces antibodies.

Adrenal Gland

Endocrine glands that respond to stress and regulate blood pressure and metabolism.

Pancreas

Dual-function organ that secretes digestive enzymes and produces hormones including insulin and glucagon to regulate blood sugar.

Lymphatic System

Body system that protects from invaders, maintains fluid balance, absorbs digestive fats, and removes cellular waste while working with the circulatory system.

Lymph

A colorless fluid containing white blood cells that drains through the lymphatic system and returns to the bloodstream.

Lymph Nodes

Bean-shaped structures that filter lymph and contain lymphocytes to fight infection.

Tonsils

Masses of lymph tissue that filter interstitial fluid.

Spleen

A major lymphatic organ that produces antibodies, destroys old blood cells, and filters waste.

Bone Marrow

Primary tissue responsible for producing blood cells.

Epidermis

The outermost layer of the skin composed of multiple sublayers, from which hair grows and melanin determines pigmentation.

Dermis

The middle skin layer containing capillaries, nerve endings, glands, and hair follicles.

Hypodermis

The subcutaneous skin layer composed of fatty tissue and nerves.

Nails

Integumentary structures made of hard keratin that cover and protect the fingers and toes.

Sweat Glands

Integumentary glands that secrete sweat to regulate body temperature.

Axial Skeleton

The central skeletal division comprising $80$ bones that provides structure, support, and protection.

Appendicular Skeleton

The skeletal division comprising $126$ bones that facilitates limb movement.

Cartilage

Connective tissue found in joints, nose, and ears that cushions bones against friction.

Joints

Points at which bones meet to allow movement; includes ball-and-socket, hinge, and pivot joints.

Tendons

Fibrous connective bands that attach muscle to bone.

Ligaments

Fibrous connective bands that attach bone to bone.

Skeletal Muscle

Voluntary muscle tissue made of fibers that moves bones via contraction and extension.

Smooth Muscle

Involuntary muscle tissue that controls unconscious internal activities including digestion and breathing.

Cardiac Muscle

Involuntary muscle tissue found exclusively in the heart.

Neuron

Nerve cell consisting of a cell body, dendrites, and axons; divided into sensory neurons, interneurons, and motor neurons.

Central Nervous System

The primary nervous system division consisting of the brain and spinal cord.

Peripheral Nervous System

The division of the nervous system outside the brain and spinal cord, subdivided into the autonomic (sympathetic and parasympathetic) and somatic nervous systems.