Respiratory System

Functions

• Supply oxygen to the body• Breathing the movement of chest that brings

air into lungs and removes waste gases• Cellular respiration oxygen is used by the

cells to release energy from glucose– Waste products of carbon dioxide and water

Organs

• Pharynx tube-like passage used by food, liquid, and air. Lower end has tissue flap called epiglottis to prevent food from entering airway

• Larynx contains vocal cords used to speak• Trachea tube held open by rings of cartilage, lined with

cilia and mucous• Bronchi the two short branches the trachea splits into• Bronchioles smallest tubes• Alveoli clusters at end of bronchioles that are surrounded

by capillaries. This is where oxygen enters blood and waste products exit blood

Breathing

• Signals from brain tell muscles in chest and abdomen to contract and relax

• If carbon dioxide levels in blood increase, breathing rate increase, and vice versa

• Diaphram muscle that contracts and relaxes to move gas into and out of the lungs

Diseases• Respiratory infections colds, flu, pneumonia• Chronic bronchitis bronchial tubes become irritated and swell; too

much mucus produced, excess coughing can damage cilia, form scar tissue, and reduce function

• Emphysema disease of alveoli, which enlarge and fail to function effectively– Causes shortness of breath– Can lead to heart problems

• Lung cancer uncontrolled cell growth in lung tissue– Smoking greatest contributing factor– Tar and other ingredients are carcinogens

• Asthma bronchial tubes contract quickly, causing shortness of breath, wheezing, coughing

Excretion

Functions

• Remove body wastes through skin, digestive, circulatory, respiratory, and urinary systems

• Urinary system gets rid of cell waste that accumulates in blood and controls blood volume

• Part of brain called hypothalamus controls amount of water in blood– If too much water, hormones tell kidneys to increase

amount of urine and return less water to blood

Organs of Urinary System

• Kidneys pass blood through filtering units called nephrons

• Urine drains from kidneys to the bladder through tubes called ureters

• Urethra passes urine out of the body• Liver produces a chemical called urea which

ends up in urine

Diseases

• Bladder infections• Kidney failure– A person with one kidney can live normally– If both kidneys fail, the person may need a dialysis

machine to filter blood