Human Organ Systems

Organ Systems

• Nervous system: brain, spinal cord, nerves
• Circulatory system: heart, blood vessels, blood
• Respiratory system: lungs, trachea, bronchi, diaphragm
• Digestive system: mouth, esophagus, stomach, small intestine, large intestine
• Endocrine system: glands that produce hormones (e.g. thyroid, adrenal glands)
• Integumentary system: skin, hair, nails, sweat glands
• Muscular system: skeletal muscles, smooth muscles, cardiac muscles
• Skeletal system: bones, cartilage, ligaments
• Urinary system: kidneys, ureters, bladder, urethra
• Reproductive system: sex organs (e.g. ovaries, testes, uterus, penis)

Body Cavities

• Cranial cavity: contains the brain
• Thoracic cavity: contains the heart, lungs, and major blood vessels
• Abdominal cavity: contains the digestive organs
• Pelvic cavity: contains the reproductive organs

Body Regions

• Head: skull, face, brain
• Neck: cervical vertebrae, trachea, esophagus
• Thorax: chest, lungs, heart
• Abdomen: belly, digestive organs
• Back: spine, muscles, skin
• Upper limb: arm, forearm, hand
• Lower limb: leg, thigh, foot

Directional Terms

• Anterior: front
• Posterior: back
• Superior: above
• Inferior: below
• Medial: towards the midline
• Lateral: away from the midline
• Proximal: near the trunk
• Distal: away from the trunk

Anatomical Position

• Standing upright
• Feet together
• Arms at sides
• Palms facing forward
• Used as a reference point for directional terms

Organ Systems

• The nervous system consists of the brain, spinal cord, and nerves
• The circulatory system is made up of the heart, blood vessels, and blood
• The respiratory system includes the lungs, trachea, bronchi, and diaphragm
• The digestive system comprises the mouth, esophagus, stomach, small intestine, and large intestine
• The endocrine system is composed of glands that produce hormones, such as the thyroid and adrenal glands
• The integumentary system includes the skin, hair, nails, and sweat glands
• The muscular system is divided into skeletal muscles, smooth muscles, and cardiac muscles
• The skeletal system consists of bones, cartilage, and ligaments
• The urinary system is made up of the kidneys, ureters, bladder, and urethra
• The reproductive system includes the sex organs, such as ovaries, testes, uterus, and penis

Body Cavities

• The cranial cavity houses the brain
• The thoracic cavity contains the heart, lungs, and major blood vessels
• The abdominal cavity contains the digestive organs
• The pelvic cavity contains the reproductive organs

Body Regions

• The head region includes the skull, face, and brain
• The neck region consists of the cervical vertebrae, trachea, and esophagus
• The thorax region includes the chest, lungs, and heart
• The abdomen region is also known as the belly and contains the digestive organs
• The back region includes the spine, muscles, and skin
• The upper limb region consists of the arm, forearm, and hand
• The lower limb region includes the leg, thigh, and foot

Directional Terms

• Anterior refers to the front of the body
• Posterior refers to the back of the body
• Superior refers to a location above another
• Inferior refers to a location below another
• Medial refers to a location towards the midline of the body
• Lateral refers to a location away from the midline of the body
• Proximal refers to a location near the trunk of the body
• Distal refers to a location away from the trunk of the body

Anatomical Position

• The anatomical position is a standard reference point for directional terms
• It is characterized by standing upright with feet together, arms at sides, and palms facing forward