Respiratory System Pg. 428 - 435 & 636 - 637 Pg. 428 – 435 & Pg. 636 - 637

Respiratory System Function: RESPIRATION - Exchange of gases between body & environment. You INHALE & EXHALE approx. 16 – 24 X’s a minute. You BREATHE more than 21,000 X’s in one day. Pg. 428

RESPIRATION Two Phases of Respiration External Respiration: Exchange of O2 & CO2 between AIR & BLOOD in lungs. Lungs  O2  Blood 2. Internal Respiration: Exchange of gases between BLOOD & BODY cells. Blood  O2  Cells Cells  CO2  Blood Pg. 428

Upper Respiratory Tract Nose  Pharynx Mouth & Nose - Air enters and exits your body. Nostrils - hairs filter particles. Nasal Cavity - warms & moistens air. Cilia – Tiny hair-like structures Trap particles & eliminates mucus from RS. Mucus Membrane – Keeps passageways from drying out. - Traps & removes foreign particles - Dust, dirt, bacteria, viruses Pg. 430

Upper Respiratory Tract Sinuses - Air filled spaces above nose & throat. Pharynx - (Throat) Two openings 1. Larynx – voice box 2. Esophagus – food tube Pg. 430

Lower Respiratory Tract Larynx  Lungs Larynx – Voice box, connects pharynx to trachea. - Vocal Chords: elastic tissue - air passes between chords when you exhale. - vibrations cause sound. Epiglottis - flap of cartilage - folds down to close off entrance to larynx & trachea when you swallow. Pg. 431

Lower Respiratory Tract Trachea - Wind pipe (in front of esophagus) - C – shaped rings of cartilage to give strength. - Serves as an air passage between upper and lower tract. - lining covered with mucus and cilia. Pg. 431

Lower Respiratory Tract Bronchi - the airways that connect Trachea & Lungs. Pg. 429

Lower Respiratory Tract Alveoli - thin walled air sacs covered w/ capillaries. - Gas exchange takes place here as O2 & CO2 diffuse across capillary walls. Pg. 429

Lower Respiratory Tract Lungs – Principle organ of the RS Found w/in chest cavity Protected by Ribs Pg. 429

Lower Respiratory Tract Diaphragm Muscle that causes chest cavity to expand and contract. Pg. 429

The Breathing Process INHALE: Made possible by creating a pressure difference between the lungs and the outside of the body. INHALE: When lungs expand, pressure inside them becomes lower than the pressure outside body. Air naturally flows into lungs to equalize the pressure. Pg. 430

The Breathing Process EXHALE: When lungs relax, pressure in lungs is higher than pressure outside your body. Air naturally flows out of lungs to area of lower pressure.

Contract = Inhale Relax = Exhale Pg. 429

Sequence For Respiration Breathing  O2 inhaled Circulation  O2 carried to cells Respiration  O2 & Glucose combine in a chemical reaction to release energy Circulation  CO2 carried to lungs Breathing  CO2 is exhaled