Organ Systems

Mader Chapter 4.3

A. Organ Systems: Integumentary System—largest single organ of the

body that has a protective function, synthesizes vitamin D, collects sensory data, and helps regulate body temperature.

Cardiovascular System—transports nutrients & O2 to cells and transports wastes away from cells; also defends against disease.

Lymphatic System—immunity, defends against disease, absorbs fats, & drainage of tissue fluid.

Digestive System—ingestion & digestion of food, absorbs nutrients and eliminates waste materials.

Urinary System—eliminates metabolic wastes and helps control fluid & pH balance.

Respiratory System—gaseous exchange at lungs & tissues and helps control pH balance.

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● Skeletal System—internal support & protection and production of blood cells.

● Muscular System—moves body & internal organs and produces body heat.

● Nervous System—receives sensory input, integrates, & initiates motor output.

● Endocrine System—produces hormones for regulation of body tissues.

● Reproductive System—production of gametes & sex hormones and nurtures offspring.

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Integument

Integumentary system—made up of the skin, hair, nails, sweat glands, and sebaceous glands.*Epidermis—stratified squamous epithelium

composed of keratinocytes and melanocytes.

*Dermis—dense fibrous connective tissue containing sensory receptors, blood vessels, & glands.

*Subcutaneous layer—loose connective tissue and adipose tissue, which stores fat.

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Accessory Organs of the Skin:*Nails—sheets of hard keratinized cells forming a

protective covering for the fingers and toes.

*Hair follicles—found in the dermis and where sebum is released to lubricate the hair.

*Sweat glands—play a role in modifying body temperature and have ducts that lead to a pore at the surface of the skin.

*Oil glands—secrete sebum, an oily substance that lubricates the skin and hair.

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UV Damages Skin

B. Body Cavities:

1. Ventral body cavity (coelom)—largest cavity located on the front side of the body.

a. Thoracic cavity—encloses & protects the heart and lungs.

----------Diaphragm (breathing muscle)-----------------

b. Abdominal cavity—below the diaphragm and encloses the stomach, liver, spleen, intestines, reproductive organs, and urinary organs.

2. Dorsal body cavity—smallest cavity located on the backside of the body.

a. Cranial cavity—protects the brain.b. Vertebral cavity—protects the spinal cord.

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C. Body Membranes:1. Mucous membranes—line body cavities that open DIRECTLY to the outside of the body.

ex. Tubes of the digestive, respiratory, urinary, and reproductive systems.

**Goblet cells—secrete mucus for protection & keeps membranes from drying out.2. Serous membranes—line body cavities that DO NOT open directly to the outside of the body.

ex. Thoracic and abdominal cavities.**Serous fluid—lubricates and reduces

friction between moving layers of tissue.

Peritonitis—inflammation of the peritoneum. 4-19

Body Membranes cont.

3. Synovial membranes—line movable joint cavities of the skeleton.

ex. Ball-&-socket joints, hinge joints, & pivot joint.

**Synovial fluid—lubricates the ends of long bones so that they can move freely.

Rheumatoid Arthritis—synovial membrane becomes inflamed and grows thicker, restricting movement.

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Human Systems Work Together

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