An overview of the human body systems Human Anatomy An overview of the human body systems
Anatomy Anatomy is the scientific discipline that investigates the body’s structure. It examines the relationship between the structure of a body part and its function.
Levels of organization Chemical level Cell level Tissue level Organ level Organ system level Organism level
Chemical level Smallest level of organization. It involves atoms & molecules.
Cell level This level involves cells (basic units of all living things) & their organelles.
Tissue level A tissue is a group of similar cells & materials surrounding them. Examples: heart tissue, muscle tissue
Organ level An organ is composed of 2 or more tissue types that perform one or more common functions. Examples: heart, lungs
Organ system level A group of organs that have a common function or set of functions & are therefore viewed as a unit. Examples: digestive system, nervous system
Organism level An organism is any living thing considered as a whole, whether composed of one cell or trillions of cells. Examples: bacterium, human
Integumentary system Organs of the integumentary system: Skin Accessory structures—hair, nails & sweat glands
Integumentary system
Integumentary system This system, in particular the skin, forms a protective barrier around the body. The skin also helps prevent water loss & control body temperature.
Integumentary system The skin also gathers information about the surroundings.
Skeletal system – Organs Bones Cartilage Tendons Ligaments
Skeletal system
Skeletal system This system… Helps you move. Protects your internal organs. Gives your body shape & support. Stores minerals. Produces blood cells.
Muscular system – Organs Muscles Skeletal (voluntary movement) Smooth (involuntary movement) Cardiac (involuntary movement)
Muscular system
Muscular system This system is responsible for voluntary movements (I.e., jumping & pointing) and involuntary movements (I.e., beating of your heart and the churning of your stomach).
Nervous system – Organs Brain Spinal cord Nerves Sensory receptors
Nervous system
Nervous system This system detects changes outside and inside the body and controls the way the body responds to these changes.
Endocrine system – Organs Pituitary gland Hypothalamus gland Thyroid gland Parathyroid glands Adrenal glands Pancreas Pineal body Thymus Ovaries Testes
Endocrine system
Endocrine system This system produces chemical messengers called hormones. Some hormones help to maintain homeostasis. Other hormones control development & growth.
Circulatory system– Organs Heart Blood Blood vessels—veins & arteries
Heart
Circulatory system
Circulatory system This system transports oxygen and nutrients to the cells and carries wastes away from cells.
Lymphatic system – Organs Lymphatic vessels Lymph nodes Lymph Lymphocytes Spleen Tonsils
Lymphatic system
Lymphatic system This system takes fluid from the spaces between cells and returns it to the circulatory system. It also filters bacteria and other microorganisms from this fluid.
Immune system The immune system is a functional system rather than an organ system in an anatomical sense. Certain organs of the body (lymphatic & circulatory systems) are intimately involved with the immune response.
Immune system
Immune system This system protects the body from infection.
Respiratory system–Organs Nasal cavity Pharynx Trachea Bronchi Lungs
Respiratory system
Respiratory system This system moves oxygen into the body and carbon dioxide out of the body.
Digestive system – Organs Gastrointestinal tract—mouth, esophagus, stomach, small intestine & large intestine Accessory organs—liver, gallbladder & pancreas
Digestive system
Digestive system This system digests (breaks down) food and absorbs nutrients.
Excretory system – Organs Kidneys Ureters Bladder Urethra
Excretory system
Excretory system This system removes wastes from the body & helps maintain homeostasis.
Reproductive system–Organs Testes Epididymis Vas deferens Seminal vesicles Prostate gland Cowper’s glands Urethra Penis
Reproductive system–Organs External parts: Vulva Labia majora Labia minora Internal parts: Ovaries Fallopian tubes Uterus Vagina
Female reproductive system Female reproductive system
Male reproductive system Male reproductive system
Reproductive system In males, this system produces sperm. In females, this system produces eggs.