BIO 8.1/8.2
Body Systems
Levels of Organization
Cell: Smallest unit of life; specialized to perform particular tasks. Examples include muscle cell and skin cell.
Tissue: A group of cells working together.
Organ: A group of tissues that carry out a specific function.
Organ System: Two or more organs working together to perform body functions.
Organism: All body systems working together to form a complete organism.
Human Body Systems (Updated 2024)
Presented by the Amoeba Sisters.
Circulatory System
Function:
Brings oxygen, nutrients, and hormones to cells.
Removes waste from cells.
Regulates body temperature.
Interconnection:
Interacts with nearly all other systems as it carries gases, hormones, and nutrients to all cells.
Circulatory System: Organs/Tissues/Cells
Heart: The primary pump for circulating blood.
Blood Vessels:
Arteries: Carry blood away from the heart.
Blood:
Red Blood Cells: Carry oxygen to body cells.
White Blood Cells: Defend the body against disease.
Respiratory System
Function:
Provides oxygen needed for cellular respiration.
Removes carbon dioxide from the body.
Interconnection:
Works with the Circulatory System (O2 transport) and Excretory System (removal of CO2).
Respiratory System: Organs/Tissues/Cells
Nose and Mouth: Site where respiration begins by inhaling air.
Trachea (Windpipe): Passes air into the bronchi.
Bronchi: Air passages from trachea to lungs.
Lungs: Facilitate gas exchange.
Diaphragm: Muscle crucial for breathing.
Alveoli: Sacs where oxygen and carbon dioxide are exchanged.
Skeletal System
Function:
Supports body, protects internal organs, allows movement, stores minerals, and facilitates blood cell formation.
Interconnection:
Works with the Muscular System for movement, and supplies blood cells through the Circulatory and Immune Systems.
Skeletal System: Organs/Tissues/Cells
Bones: Produce blood cells.
Joints: Where two bones meet.
Ligaments: Connect bones to one another.
Tendons: Connect muscles to bones.
Nervous System
Function:
Recognizes and coordinates body responses to internal and external changes.
Interconnection:
Works closely with the Digestive and Muscular Systems.
Nervous System: Organs/Tissues/Cells
Neurons (Nerve Cells): Basic units of structure and function.
Brain: Control center of the nervous system.
Spinal Cord: Transmits messages between brain and body.
Muscular System
Function:
Produces movement, aids in circulating blood and moving food through the digestive tract.
Interconnection:
Works with the Skeletal System for movement, the Circulatory System for oxygen supply, and the Nervous System for muscle contraction.
Muscular System: Organs/Tissues/Cells
Skeletal Muscle (Voluntary): Moves bones.
Smooth Muscle (Involuntary): Lines walls of internal organs and blood vessels.
Cardiac Muscle: Forms the heart.
Digestive System
Function:
Converts food into simpler molecules for cells, absorbs food, and eliminates waste.
Interconnection:
Involves Muscular, Nervous, Circulatory, and Endocrine Systems.
Digestive System: Organs/Tissues/Cells
Mouth: Initial site of mechanical and chemical digestion.
Esophagus: Links mouth to stomach.
Pancreas: Secretes enzymes for digestion.
Liver: Produces bile to help digest fats.
Gallbladder: Stores bile.
Digestive System: Continued
Stomach: Muscle pouch for churning and chemical digestion.
Small Intestine: Completes digestion with liver and pancreas enzymes.
Large Intestine (Colon): Absorbs water and salts.
Rectum: Final segment of the digestive system, where feces are eliminated.
Urinary/Excretory System
Function:
Filters blood, maintains electrolyte balance, and eliminates waste.
Interconnection:
Works with Circulatory and Endocrine Systems.
Urinary/Excretory System: Organs/Tissues/Cells
Kidneys: Filter blood to maintain homeostasis.
Ureters: Connect kidneys to bladder.
Urinary Bladder: Holds urine.
Urethra: Tube for urine expulsion.
Immune and Lymphatic Systems
Immune System: Protects body from disease.
Lymphatic System: Collects fluids from blood vessels, returning them to the circulatory system.
Interconnection:
Works with the Circulatory System.
Immune and Lymphatic Systems: Organs/Tissues/Cells
Immune:
White Blood Cells: Fight infections.
Lymphatic:
Thymus: Develops T cells.
Spleen: Filters blood.
Lymph Vessels: Transport lymph fluid with white blood cells.
Lymph Nodes: Filter lymph to trap foreign particles.
Reproductive System
Function:
Produces reproductive cells and nurtures developing embryos in females.
Interconnection:
Closely interacts with the Endocrine System (hormones).
Reproductive System: Males Organs/Tissues/Cells
Penis: Delivers sperm.
Testes: Site of sperm production.
Epididymis: Where sperm matures.
Vas Deferens: Duct storing mature sperm before urethra.
Urethra: Expels sperm.
Reproductive System: Females Organs/Tissues/Cells
Ovaries: Maturation site for eggs.
Fallopian Tubes: Connect ovaries to uterus.
Uterus: Where fetal development occurs.
Vagina: Canal leading to the uterus.
Integumentary System
Function:
First line of defense against infection, regulates temperature, and protects against UV radiation.
Interconnection:
Contains blood vessels and nerves.
Integumentary System: Organs/Tissues/Cells
Skin:
Epidermis: Outermost layer.
Dermis: Contains vessels, nerves, and glands.
Hair, Skin, and Nails: Composed of keratin.
Endocrine System
Function:
Controls growth, development, metabolism, and homeostasis.
Interconnection:
Works with the Reproductive and Digestive Systems.
Endocrine System: Organs/Tissues/Cells
Hypothalamus: Links endocrine and nervous systems.
Pituitary Gland: Main gland of the endocrine system.
Thyroid Gland: Regulates metabolism.
Endocrine System: Continued
Adrenal Glands: Prepare body for stress by releasing hormones such as:
Epinephrine (Adrenaline): Increases blood pressure and heart rate.
Corticosteroids: Regulate salt and water balance.
Endocrine System: Continued
Pancreas: Produces insulin and glucagon to maintain blood glucose levels.
Ovaries: Secrete female sex hormones.
Testes: Secrete male sex hormones.