1. Organ Systems of the Body Anatomy and Physiology 1 Mrs. Hendricks

2. Overview and Definitions 1.Organ: a structure made up of two or more kinds of tissues organized in such a way that the tissues can together perform a more complex function than can any tissue alone 2.System: a group of organs arranged in such a way that they can together perform a more complex function than can any organ alone 3.There are 11 major organ systems of the body

3. Integumentary System 1.The skin is the largest and most important organ in this system 2.Its weight in average adults is 20 pounds or more and accounts for approximately 16% of body weight and is the heaviest organ in the body 3.It includes the skin and its appendages, which include the hair, nails, sense receptors, sweat glands, and oil glands 4.The specialized sense receptors allow the body to respond to a variety of stimuli such as pain, pressure, touch, and temperature change

4. 5. This system is crucial to survival and the primary function is protection of your underlying organs and bones from damage, bacteria, or chemicals

5. Skeletal System 1.In this system, there are 206 individual bones 2.Examples include the sternum (breastbone), humerus (top portion of the arm) and femur (top portion of the leg) 3.Other portions in this system are related tissues such as cartilage and ligaments that provide the body with a rigid framework for support and protection 4.Finally, the system includes joints, found between bones, and allows body movement – (without them, no movement occurs) 5.Bones are also storage areas for minerals (calcium and phosphorus), and formation of blood cells occurs in the red marrow of certain bones

7. Muscular System 1.Made of individual skeletal muscles, which are the organs of this system, along with tendons 2.They produce movement, maintain body posture, and generate heat for core body temperature 3.Skeletal muscles are voluntary muscles, as contractions are under conscious control 4.Involuntary muscles, known as smooth muscle tissue is found in blood vessel walls, other tubular structures, and in the lining of hollow organs such as the stomach and small intestine

8. 5.Cardiac muscle is specialized and found in the tissue of the heart 6.Tendons are how muscles are attached to bones 7.When muscles are stimulated, they shorten and contract

9. Nervous System 1.Major organs are the brain, spinal cord and nerves 2.Nerves extend from the brain and spinal cord to every body area 3.Functions include: Communication between, integration, and control of body functions, as well as recognition of sensory stimuli 4.Nerve impulses are the specialized signals that occur allowing for us to chew food and produce a coordinated muscular movement 5.Other nerve impulses cause glands to secrete fluids

10. 6.Stimuli are recognized by the nervous system due to heat, light, pressure, or temperature 7.When stimulated the sense organs generate nerve impulses that travel to the brain or spinal cord and relay information where appropriate

11. Endocrine System 1.This system is composed of specialized glands that secrete chemicals known as hormones directly into the blood 2.Organs of this system are ductless glands, and have the same general function as the nervous system which is to communicate, integrate (work together), and control 3.The impulses of the nervous system are rapid and brief, however, the endocrine system provides slower but longer-lasting control by hormone secretion 4.Example: Growth hormone controls rate of development over long periods of gradual growth

12. 5.In addition to growth control, hormones regulate metabolism, reproduction, and other body activities such as fluid and electrolyte balance, acid- base balance (pH) and energy metabolism 6.Endocrine glands are widely distributed and are located as follows: a. Pituitary gland, pineal gland, and hypothalamus are found in the skull b. Thyroid and parathyroid glands are in the neck c. Thymus gland is in the thoracic cavity (mediastinum specifically) d. Adrenal glands and pancreas are in the abdominal cavity e. Note that the ovaries and testes also function in the endocrine system (in the pelvic cavity)

14. Cardiovascular (Circulatory) System 1.Major organs include the heart (muscular pump) and a closed sytem of vessels made up of arteries, veins, and capillaries 2.Primary function of this system is transportation and is critical for life 3.Transportation needs include continuous movement of oxygen (O 2 ), carbon dioxide (CO 2 ), nutrients, hormones and other important substances 4.Waste products are also released into the bloodstream on an ongoing basis and are transported by the blood to the excretory organs

15. 5.Also regulates body temperature by distributing heat and by retaining or releasing heat from the body by regulating blood flow near the body surface 6.Certain cells of the circulatory system are also involved in immunity or body defense (white blood cells)

16. Lymphatic System 1.Composed of lymph nodes, lymphatic vessels and specialized organs such as tonsils, thymus, and spleen 2.Thymus function as endocrine and a lymphatic gland 3.Instead of blood, lymphatic vessels are filled with lymph, a whitish, watery fluid that contains lymphocytes, proteins, and some fatty molecules 4.No red blood cells are present, but lymph is formed from fluid around the body cells and diffuses into the lymph vessels 5.Lymph does not circulate in a closed system (like blood) but instead eventually enters the circulatory system by passing through large ducts including the thoracic duct

17. 6.Thoracic duct connects with veins in the upper area of the thoracic cavity 7.Collections of lymph nodes can be seen in the axillary (armpit) and in the inguinal (groin) areas 8.Functions include movement of fluids and certain large molecules from tissues spaces around the cells 9.Also movement of fat-related nutrients from the digestive tract back to the blood 10.Lymphatic system is involved in the functioning of the immune system, playing a critical role in defense mechanisms against disease

19. Respiratory System 1.Organs of the respiratory system include the nose, pharynx (throat), larynx (voice box), trachea (wind pipe), bronchi, and lungs. 2.Together these organs permit the movement of air into the tiny, thin walled sacs of the lungs (alveoli) where O 2 is exchanged for the waste product CO 2, and is carried to the lungs by the blood to be eliminated from the body 3.The respiratory organs also function to include: warming and humidifying air in cool or dry environments, inhaled irritants such as pollen or dust can be trapped in the sticky mucus that covers the lining of respiratory passages, and helps to regulate acid-base balances.

21. Digestive System 1.Typically separated into two groups: primary and secondary organs, both of which work together to ensure proper digestion and absorption of nutrients 2.Primary organs: mouth, pharynx, esophagus, stomach, small and large intestine, rectum and anal canal – form a tube (open at both ends) and are known as the gastrointestinal tract (GI) 3.Secondary organs: teeth, salivary glands, tongue, liver, gallbladder, pancreas and appendix (purpose?)

22. 4.Food entering the GI tract is digested, nutrients are absorbed, and undigested residue is eliminated from the body as waste known as feces 5.Accessory organs assist in the mechanical or chemical breakdown of ingested food 6.Appendix is attached to the digestive tube but is not actually part of the digestive process; inflammation of the appendix is serious, does cause problems and is known as appendicitis.

24. Urinary System 1.The organs of the urinary system include the kidneys, ureters, bladder, and urethra. 2.The kidneys function to clear/clean the blood of the waste products continually produced by metabolism of nutrients, and maintain electrolytes, water, and acid-base balances in the body 3.Urine is the waste product the kidneys produce and it is produced by flowing out of the kidneys through the ureters, into the urinary bladder, and is stored. We pass our urine out of the urethra, in males through the penis (doubles for seminal fluid also), however, in females, it is solely for passing urine

25. 4. The organs of the urinary system are not the only waste eliminators in the body. Undigested food residues leave the intestinal tract as feces, the lungs rid the body of CO2 and the skin serves as an excretory function to eliminate water and some salts in our sweat.

26. Reproductive System 1.Normal function of this system ensures survival of the human race. Additionally, production of hormones to permit the development of sexual characteristics occur. 2.Male Reproductive System a. Organs include the gonads (called testes), which produce the sex cells or sperm. b. The important genital ducts, known as the vas deferens and the prostate, are classified as accessory organs in the male

27. c. The penis and scrotum are supporting structure and together are known as genitalia. d. The urethra is part of the urinary system, passes through the penis and carries sperm too. e. Sperm is produced by the testes, travels through the vas deferens and exits the body to hopefully fertilize the egg in the female reproductive tract. The prostate and other accessory organs add fluid and nutrients to the sex cells as they pass through the ducts and supporting structures (penis).

28. 3.Female Reproductive System a. The female gonads are the ovaries. b. The accessory organs include the uterus, uterine or fallopian tubes and the vagina. c. In females, the vulva is used to describe the external genitalia. d. The breasts or mammary glands are also classified as external accessory sex organs. e. The reproductive cell is the ovum, and it must be fertilized by the male sperm to permit fertilization. The uterus will then house the developing offspring in preparation for birth.