Human Body Systems November 2009

Respiratory System l Function: l Keeps blood constantly supplied with oxygen and removes carbon dioxide l Gas exchange occurs through the walls of the air sacs of the lungs l Breathing brings air into the lungs and breathing out removes waste gases

Respiratory system l Upper respiratory tract: nasal cavity, pharynx, larynx l Lower respiratory tract: trachea, bronchi, lungs

Fact l The surface area of the aveoli in your lungs 70 square meters, or about the same as three lanes of a bowling alley.

Diseases of respiratory system l Lung Cancer -3rd leading cause of death in men and women in the U.S. l Emphysema ( causes aveoli to enlarge) l Asthma (lung disorder)

Circulartory System l Blood vessels transport blood which carries – Oxygen – Carbon dioxide – Nutrients – Wastes, etc. l Heart pumps blood l Oxygen rich blood is moved to all tissues and organs of the body and is called systemic circulation.

Organs of the circulatory system l Heart l Veins l Arteries l Capillaries

Heart l Made of cardiac muscle tissue l Has 4 compartments called chambers: two upper are atriums, two lower are ventricles. l Heart has arteries just and veins just like any other muscle

Fact l Your heart beats times per minute. Each time it pumps 60 mL of blood. How many mL’s in 24 hours. l mL’s or l 5184 liter bottles.

Heart l When these arteries are blocked, it starves the heart of oxygen and nutrients, resulting in a heart attack

Veins l Veins carry blood back to the heart. l Veins have valves l 2 major veins carry return blood from your body to your heart: the superior vena cava returns blood from your head and the inferior vena cava from your lower body

Arteries l Carry blood away from your heart l Have thick, elastic walls made of tissue and smooth muscle

Capillaries l Microscopic blood vessels. l Walls are only one cell thick l Bloodshot eyes l Nutrients and oxygen diffuse from body cells into capillaries

Blood pressure l The force of the blood against the walls of your blood vessels. l Measured in two numbers: l Systolic is the first number and measures your heart pumping. l Diastolic is the second number and measures pressure that occurs as the ventricles fill with blood before they contract again.

Atherosclerosis l Fatty deposits build up on arterial walls. Eating fatty foods high in cholesterol and saturated fats can cause these deposits to form. l Not all cholesterol is bad, and is essential for health.

Blood l Carries oxygen from lungs to body l Takes carbon dioxide away l Carries waste products to kidneys l Transports nutrients l Cells in blood fight infections

Blood l Made up of plasma (55%), mostly water. l Platelets ;help with clotting l Red blood cells: made at rate of 2-3 million per second. l White: help fight bacteria, viruses, etc

Blood Types Blood Types l 4 types l A, B, AB, O l Types A, B, AB have antigens coating their surface. Rh factor l Wrong type of blood will kill you l Type “O” is universal

Diseases of the Blood l Sickle-cell anemia l Anemia is a disease of the red blood cells l Leukemia produces immature white blood cells that don’t fight infections

Fact l First blood transfusion was in early 1800”s. l French physician Jean Baptiste Denis successfully used sheep’s blood. His second patient died.

Excretory System l Includes many systems such as digestive, respiratory, skin and urinary system. l Each gets rid of waste in its own way.

Digestive System l Breaks down food into absorbable units that enter the blood for distribution to body cells l Intestines absorb water l Indigestible foodstuffs are eliminated as feces

Main Organs of theDigestive System l Mouth l Pharynx l Oesophagus l Stomach l Small Intestine l Large Intestine

Urinary System l Water and salts in l Excess water, metabolic wastes and salts out. l Controls blood volume ( blood pressure) l Works in conjunction with hypothalmus to balance fluid levels in blood

Organs of Urinary System l Kidneys are bean shaped organs l Located at back of abdomen waist level l Kidney filters blood of waste products, creates waste product called urine l Bladder l Ureter & Urethra

Kidneys l All of your blood is filtered through your kidneys in about 5 minutes. l Connected to bladder through two ducts called ureters l Drains urine into your bladder

Bladder l Bladder is where urine is held until you release it. l Bladder is an elastic, muscular organ that can stretch to hold.5 liter of urine. l Avg. human 1 liter of urine daily

Diseases of the Urinary System l A person can live normally with one kidney l If both kidneys fail, a person must use a dialysis machine to filter wastes out of the blood; or else you would die.

Skeletal System l Skeletal system l Function: l Shape and support l Produces red blood cells l Stores minerals l Protect organs and soft tissue l At birth you 300 bones l As an adult 206 bones

Main Organs of the Skeletal System l Bones l Bone marrow l Joints l Teeth

Muscular System l Over 600 muscles in your body l Control movement l Voluntary muscles: you choose to move them l Involuntary: heart

Muscles l 3 types l Skeletal: attached to bones to help you move l Cardiac: heart l Smooth: intestines, bladder, blood vessels, internal organs

Nervous System l Responds to stimuli to maintain homeostasis l Central nervous is your brain and spinal cord. l Fast acting body control l Responds to internal and external changes

Main Organs of theNervous System l Brain l Brain stem l Spinal cord l neurons

Brain l Three main parts: l Cerebrum l Cerebellum l Brain stem l You also have a left and right half

Brain l Your brain 100 billion neurons l Cerebrum: interprets input from senses l Controls movement l Responsible for learning and memory

Brain l Cerebellum l Responsible for coordinating your muscles and balance l Keeps you from falling down when you walk

Brain l Brain stem l Controls involuntary actions such as breathing and heartbeat