Human Body Systems PDF

Human Body Systems Siobhán O’Connor MSc PhD Certified Athletic Therapist (CAT) Remember, the human body is organized in several levels, from the simplest to the most complex. . . Cells – the basic unit of life Levels of organization Tissues – clusters of cells performing a similar function Org...

Human Body Systems Siobhán O’Connor MSc PhD Certified Athletic Therapist (CAT) Remember, the human body is organized in several levels, from the simplest to the most complex. . . Cells – the basic unit of life Levels of organization Tissues – clusters of cells performing a similar function Organs – made of tissues that perform one specific function Organ Systems – groups of organs that perform a specific purpose in the human body ***The purpose of the 11 organ systems is for the human body to maintain homeostasis nervous system respiratory system excretory system muscular system endocrine system lymphatic (immune) system integumentary system digestive system skeletal system circulatory system reproductive system Respiratory System • Purpose: to provide the body with a fresh supply of oxygen for cellular respiration and remove the waste product carbon dioxide • Interactions: Circulatory system carries oxygen to the cells and carbon dioxide away. • Major Interactions: Circulatory oxygen to the cells and carbon dioxide away. Organs and system Their carries Functions – internal entry and exit pointcarries for air oxygen to the cells and carbon dioxide away. • Nose Interactions: Circulatory system Pharynx – serves as a passage way for both air and food at the back of the throat Interactions: Circulatory system carries oxygen to the cells and carbon dioxide away. Larynx – your “voicebox”, as air passes over your vocal chords, you speak Trachea – the “windpipe”, or what connects your pharynx to your lungs -- a piece of skin, called the epiglottis, covers the trachea when you swallow, preventing food from entering Bronchi – the two large passageways that lead from the trachea to your lungs (one for each lung) -- the bronchi are further subdivided into bronchioles -- eventually, the further subdivisions lead to tiny air sacs called alveoli -- alveoli are in clusters, like grapes -- capillaries surrounding each alveolus is where the exchange of gases with the blood occurs The diaphragm is the muscle that causes you to breath -- hiccups are involuntary contractions of the diaphragm Major Organs and Their Functions Nose • Internal entry and exit point for air Pharynx • Serves as a passage way for both air and food at the back of the throat Larynx • Your “voicebox”, as air passes over your vocal chords, you speak Trachea • The “windpipe”, or what connects your pharynx to your lungs • A piece of skin, called the epiglottis, covers the trachea when you swallow, preventing food from entering Bronchi • The two large passageways that lead from the trachea to your lungs (one for each lung) • The bronchi are further subdivided into bronchioles -eventually, the further subdivisions lead to tiny air sacs called alveoli Alveoli • Are in clusters, like grapes • Capillaries surrounding each alveolus is where the exchange of gases with the blood occurs Diaphragm • The muscle that causes you to breath • Hiccups are involuntary contractions of the diaphragm Major Organs Hypothalamus • Region of the brain & is the major link between nervous & endocrine system • Synthesize at least 9 diff hormones, with pituitary gland regulates virtually all aspect of growth, development, metabolism & homeostasis Pituitary gland • Pea shaped structure measuring 1-1.5cm in diameter. • Synthesizes 7 diff hormones e.g. human growth hormone, luteinizing hormone (LH), prolactin etc. Thyroid • Inferior to larynz • Releases thyroxine or tetraiodothyronine (T4), triiodothyronine (T3) & calcitonin Parathyroid glands • Releases parathyroid hormone (PTH) Adrenal glands • Lie above the kidney • Releases hormones like androgens and epinephrine and norepinephrine Pancreas • Releases glucagon, insulin etc. Testes • Releases testosterone and inhibin Ovaries • Releases ovarian hormones e.g. estrogens and progesterone, relaxin,etc Endocrine Purpose To control growth, development, metabolism and reproduction through the production and secretion of hormones Immune (lymph) system Purpose • Remove infectious diseases & other pathogens from the human body • Works with the circulatory system to distribute fluids and nutrients throughout the body, and rids the body of unnecessary substances through a clear to yellow fluid referred to as “lymph” which contains white blood cells, proteins and fats. Immune (lymph) system Major Organs and Their Functions Skin • Also called the integumentary system, the skin is the body’s first line of defence White Blood Cells • Recognize disease agents (antigens) and create antibodies to tag and remove these antigens • Phagocytes are the white blood cell type that actually eats and destroys these antigens Lymph Nodes • Help restore fluid lost by the blood and return it to the circulatory system • 600 bean shapped lymph nodes scattered throughout the body & usually are in groups (especially in mammary glands, in axillae and groin) 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!