Ch. 13 Respiratory System

1. Ch. 13 Respiratory System Structural Plan Like an inverted tree.

2. Ch. 13 Respiratory System Upper respiratory tract Nose pharynx and larynx

3. Ch. 13 Respiratory System Lower respiratory tract Trachea, bronchial tree, lungs

4. Ch. 13 Respiratory System Respiratory mucosa Specialized membrane that lines tubes of respiratory tree. More than 125 ml of mucous produced daily Air purification system by trapping inspired irritants. Cilia on mucosal cells brat in only one direction,--- upward.

5. Ch. 13 Respiratory System Nose Structure Nasal septum separates nose into 2 cavities. Mucous membrane lines nose Sinuses drain into nose Function Warms and moistens inhaled air Contains organs of smell.

6. Ch. 13 Respiratory System Pharynx Structure Pharynx (throat) is approx. 5 in. long. Divided into nasopharynx, oropharynx & laryngopharynx. 2 nasal cavities, mouth esophagus, larynx auditory tubes open into the pharynx. Pharyngeal tonsils and openings of auditory tubes open into nasopharynx, tonsils found into oropharynx

7. Ch. 13 Respiratory System Function Passageway for food and liquids Air distribution; passageway for air

8. Ch. 13 Respiratory System Trachea Structure Tube approx 4-5 in. long Has mucous lining C-shaped cartilage rinds hold trachea open

9. Ch. 13 Respiratory System Function Passageway for air to move to and from the lungs Obstruction Blockage of trachea obstructs air and can cause death in minutes 4000 U.S. deaths annually Heimlich maneuver used to free trachea of obstruction

10. Ch. 13 Respiratory System Bronchi, bronchioles and alveoli Trachea breaks into right and left bronchi Each bronchus branches into smaller bronchioles Bronchioles end in clusters of microscopic alveolar sacs, made up of alveoli

11. Ch. 13 Respiratory System Function Bronchi and bronchioles � air distribution; passageway for air to move to and from alveoli. Alveoli � exchange of gases between air and blood.

12. Ch. 13 Respiratory System Lungs and pleura Structure Large enough to fill chest cavity, except for mediastinum that is occupied by the heart and large blood vessels. Apex - is upper part of each lung under collarbone Base � broad lower part resting on diaphragm. Pleura � moist smooth slippery membrane that lines chest cavity and covers surface of each lung. Reduces friction between lungs and chest wall.

13. Ch. 13 Respiratory System Function Breathing (pulmonary ventilation)

14. Ch. 13 Respiratory System Respiration Mechanics of breathing Breathing includes 2 phases, inspiration (air into lungs) and expiration (air out of lungs). Changes in shape and size of thorax causes changes air pressure within lungs. Air pressure differences causes air to move in and out of lungs.

15. Ch. 13 Respiratory System Inspiration Active process � air moves into lungs Inspiratory muscles include diaphragm and external intercostals. Diaphragm muscle flattens during inspiration, increases top to bottom length of thorax. External intercostals contraction elevates the size of the thorax from front to back and from side to side The increase of the size of the chest cavity reduces pressure within it, and air enters the lungs.

16. Ch. 13 Respiratory System Expiration Quiet expiration is a passive process. During expiration, thorax returns to original shape and size. Elastic recoil of lung tissue aids in expiration Expiratory muscles used in forceful expiration are internal intercostals and abdominal muscles Internal intercostals, compresses rib cage and decreases size of thorax from front to back Contraction of abdominals elevated diaphragm decreasing size from top to bottom Reduction in size of thoracic cavity increases pressure and air leaves lungs.

17. Ch. 13 Respiratory System Exchange of gases in lungs (figure 13-12) Carbaminohemoglobin breaks down into CO2 and hemoglobin. CO2 move out of lung capillary blood into alveolar air and out of the body in expired air. Oxygen moves from alveoli into lung capillaries Hemoglobin combines with oxygen to form oxyhemoglobin.

18. Ch. 13 Respiratory System Exchange of gases in tissues Oxyhemoglobin breaks down into O2 and hemoglobin O2 moves out of tissue capillary blood into tissue cells. CO2 moves from tissue cells into tissue capillary blood Hemoglobin combines with CO2 forming Carbaminohemoglobin

19. Ch. 13 Respiratory System Volumes of air exchanged in breathing Can be measured with spirometer Tidal volume � amount breathed in or out with each breath Vital capacity � greatest amount that can be breathed in out on one breath Expiratory reserve volume � amount of air forcibly exhaled after expiring tidal volume Inspiratory reserve volume � amount of air forcibly inhaled after normal inspiration Residual volume � air that remains in lungs after the most forceful expiration Rate � 12 � 18 breaths per minute, increased during exercise.

20. Ch. 13 Respiratory System Regulation of respiration Regulation of respiration permits body to adjust to varying demands for O2 supply and CO2 removal Most important regulatory centers on medulla are called respiratory control centers. Under resting conditions, nervous activity in the respiratory control centers produces a normal rate and depth of respirations (12 to 18 per minute)

21. Ch. 13 Respiratory System Control of respiration control home

22. Ch. 13 Respiratory System Respiratory control centers in the medulla are influenced by �inputs� from receptors located in other body areas: Cerebral cortex � voluntary, but limited control of respiratory activity Chemoreceptors respond to changes in CO2 and O2 and blood acid levels � located in carotid and aortic bodies Pulmonary stretch receptors � respond to the stretch of lungs, thus protecting respiratory organs from over inflation

23. Ch. 13 Respiratory System Carotid and arotic bodies

24. Ch. 13 Respiratory System Types of breathing Eupnea � normal breathing Hyperventilation � rapid and deep respirations Hypoventilation � slow and shallow respiration Dyspnea � labored or difficult respirations Apnea � stopped breathing Respiratory arrest � failure to resume breathing