Respiration The hows and whys of a breath

The Tidal movement of air

Bio 130 Human Biology Tidal movement of air n Nasal cavities n nasopharynx n pharynx n larynx n vocal cords n trachea

Bio 130 Human Biology More airways n Bronchioles n respiratory bronchioles n aveoli n can you name all the structure air passes?

Bio 130 Human Biology Human Respiratory System. Putting it all together Figure 10.1

Bio 130 Human Biology The lungs n Located in thoracic cavity above dome shaped diaphragm. n Surrounded by a sac like membrane with fluid in it called the pleural sac. n Alveoli (blind sacs) are surrounded by a dense capillary network and is site of gas exchange.

Bio 130 Human Biology Respiratory Cycle Figure 10.9

Bio 130 Human Biology Factors that effect gas exchange n Air is 21% oxygen. (partial pressure) n The pressure of air affects the amount of oxygen available. n O 2 & CO 2 move from high to low pressure. n Gas exchange occurs at the surface which must be moist. (800sq feet of surface)

Bio 130 Human Biology Lung capacity n Male 4800ml Female 3800(vital capacity) n 150ml is dead space. n 500ml is moved in and out during rest. (tidal volume) n 350ml actull reach alveoli n 1200ml of residual air is always in the lungs and cannot be forced out. (residual volume)

Bio 130 Human Biology Measurement of Lung Capacity Figure 10.10a

Bio 130 Human Biology The two sites of gas exchange n In the lungs n Oxygen has a high pressure in the lungs and flows into the blood n Carbon dioxide has a high pressure in the blood and flows out n In the tissues n oxygen moves towards the tissues n carbon dioxide moves to the blood

Bio 130 Human Biology Question n What is pulmonary surfactant?

Bio 130 Human Biology Movement of gases n Oxygen n Binds to hemoglobin in RBC. n Hemoglobin gives up oxygen under warm low pH conditions. n Carbon dioxide n 23% to hemoglobin 70% bicarbonate in blood n red blood cells convert carbon dioxide to bicarbonate

Bio 130 Human Biology Blood Transports Gases between the Lungs and the Cells n Most carbon dioxide is transported as bicarbonate ions n Bicarbonate is made in the red blood cells n Carbon dioxide and water are converted to bicarbonate ions and hydrogen. n The hydrogen is carried by hemoglobin (no ph change) n Bicarbonate circulates in the blood stream and removes excess acids.

Bio 130 Human Biology Relative gas concentrations, be able to figure out where the gas will go

Bio 130 Human Biology Control of respiration n The body tries to equilibrate blood and air flow. n Airflow can be increased by dilating bronchiole tubes. n Increased oxygen causes blood vessels to dilate.

Bio 130 Human Biology Regulation of Breathing Figure 10.13

Bio 130 Human Biology Regulation of Breathing: Nervous System Involvement n Respiratory center in the medulla oblongata: establishes basic breathing pattern n Chemical receptors: monitor carbon dioxide, hydrogen ions, and oxygen levels n Medulla: sensitive to hydrogen ions in cerebrospinal fluid resulting from carbon dioxide in blood

Bio 130 Human Biology Regulation of Breathing: Nervous System Involvement n Carotid and aortic bodies: sensitive to carbon dioxide, pH, and oxygen levels n Conscious control: resides in higher brain centers; ability to modify breath

Bio 130 Human Biology Unusual places to breath n When moving from high to low pressures, gases can escape into the blood, decompression sickness. n Hypoxia is due to low oxygen pressure at high elevations. n Carbon monoxide binds to hemoglobin better than oxygen.

Bio 130 Human Biology Disorders of Respiratory System n Reduced air flow: asthma, emphysema, bronchitis n Infections: pneumonia, tuberculosis, botulism n Lung cancer n Congestive heart failure n Cystic fibrosis