Body Systems PDF

Integumentary System • Made up of the skin, hair and nails aswell as other glands, muscles & nerves • Protects the body, regulates body temperature, acts as a sensory receptor to internal and external stimuli, excretes waste from the body trough sweat, and absorbs vitamin D and calcium from sunlight...

Integumentary System • Made up of the skin, hair and nails aswell as other glands, muscles & nerves • Protects the body, regulates body temperature, acts as a sensory receptor to internal and external stimuli, excretes waste from the body trough sweat, and absorbs vitamin D and calcium from sunlight to nourish the body. • Skin is the largest organ in the body. • In adults our skin covers an area of 2 square meters & weighs 4.5-5kg (about 16% of our body weight) Major Organs and their Functions Mouth • To chew and grind up food, saliva also begins the chemical breakdown Esophagus • Pipe connecting mouth to stomach Stomach • Secretes an extraordinarily strong acid (pH = 2) that leads to breakdown of food • Once the food is broken down in the stomach and mixed with digestive juices, it is called chyme Pancreas • Produces the hormone insulin that regulates blood sugar levels • Also help neutralize stomach acid Liver • Produces bile, which breaks down fats in foods Gallbladder • Pouch-like organ that stores bile for future use Small Intestine • After digestion is complete, the chyme enters the small intestine where it is absorbed into the bloodstream • The chyme is propelled along by folded surfaces called villi, on the intestine Large Intestine • Removes water from the chyme and gets the waste ready for excretion Digestive system Purpose: Convert food particles into simpler micromolecules that can be absorbed into the bloodstream and used by the body Circulatory system Purpose • To deliver oxygenated blood to the various cells and organ systems in your body so they can undergo cellular respiration Major Organs and Their Functions Heart • The major muscle of the circulatory system • Pumps blood through its four chambers (two ventricles and two atria) • Pumps deoxygenated blood into the lungs, where it gets oxygenated, returned to the heart, & then pumped out through the aorta to the rest of the body • The valve regulate the flow of blood between the chambers Arteries • Carry blood away from the heart and to the major organs of the body Veins • Carry blood back to the heart away from the major organs of the body Capillaries • Small blood vessels where gas exchange occurs Blood • The cells that flow through the circulatory system • Red blood cells contain hemoglobin, an iron-rich protein that carries oxygen • White blood cells function in the immune system • Platelets help in blood clotting Spleen – helps to filter out toxins in the blood Excretory System Purpose Rid the body of wastes, including excess water and salts Major Organs and Their Functions Kidneys • Main organs of the excretory system • Waste-laden blood enters the kidney and the kidney filters out urea, excess water and other waste products, which eventually travel out of the kidney as urine • Eventually they travel through the ureter to the urinary bladder Rectum • Solid (food) waste travels out of the body through the rectum Skin • Sweat glands remove excess water and salts from the body Lungs • Expel the waste gas carbon dioxide • and digestive system Scrotum • The supporting structure for the testes, consists of loose skin and superficial facia that hangs from the root of the penis Testes • Testicles, paired oval glands in the scrotum • Testes produce sperm and male sex hormone testosterone Ducts (e.g. spermatic cord etc) • Transport, store and assist in maturation of sperm Accessory sex glands (e.g. prostate) • Secrete most of the liquid portion of semen Penis • Contains the urethra a passageway for ejaculation of semen & excretion of urine Reproductive System Male Ovaries • Produce secondary oocytes and hormones (e.g. progesterone, estraogens, inhibin & relaxin) Uterine tubes (fallopian tube) • Transport secondary oocyte to the uterus & normally where site of fertilisation occurs Uterus • Site of implantation of a fertilized egg, development of the fetus during labour etc Cervix • Narrow portion at the inferior of the uterus that opens into the vagina Vagina • Receives the penis during sex & passageway for birth Vulva • External genitals of the female Reproductive System – Female Musculoskeletal system & Nervous System to follow!