April 16 17 2015 Respiratory System Respiratory Anatomy

April 16 -17, 2015 Respiratory System

Respiratory Anatomy

1. Air enters through the external nares (nostrils) 2. Nasal cavity. • Nasal cavity is lined with ciliated, mucosal epithelial tissue that trap inhaled particles and sweep them towards the throat to be swallowed and digested. • Contains three lobes (conchae) which increase the surface area of mucosa exposed to air to better trap particles 3. Pharynx (upper throat) • Passage for both food and air • Contains tonsils Flow of air The cilia in the nasal cavity don’t work as well in cold weather, which is why you may get a runny nose in the cold.

4. Larynx (aka voice box) • Acts to prevent food and liquid from going into trachea. • Epiglottis is located at the top of larynx. Normally it allows free passage of air, but when we swallow, the larynx is pulled up and the epiglottis tips over, sealing off the larynx. • The vocal cords – a pair of membranes that vibrate as we expel air are also in the larynx. The passage between the vocal cords is the glottis. Put your hand over your throat and swallow – what you feel moving is your larynx! Flow of air If food / liquid does get past the epiglottis, it triggers the cough reflex. Swallowing animation!

5. Trachea • also contains ciliated mucosa to trap particles 6. Bronchi • Largest air tubes of lungs 7. Bronchioles • Smallest of the air tubes 8. Alveoli • Site of gas exchange • Take up most of the space of the lungs • Covered with capillaries to exchange gasses with blood. Flow of air Bronchitis = inflammation of bronchi

» Sinuses • Spaces in the skull bones • Act as resonance chambers for speech and produce mucus • Sinusitis = inflammation of sinus membranes Ø Pleural membranes • Sac surrounding lungs • Fluid-filled space reduces friction as lungs expand contract • Tightly bound to thorax wall, which is essential to breathing b/c it allows the lungs to expand contract with muscular movement. Other important structures

» What structures in the respiratory system help with disease prevention? Are those structures specific or non -specific defenses? » Name some similarities between the cardiovascular and respiratory systems. Making Connections

» Inspiration • Diaphragm & external intercostals contract, expanding the chest cavity and the lung capacity. • Causes a decrease in pressure within the lungs. • Air rushes into the lungs. Watch me! Exhalation is normally passive (we just relax muscles, we do not contract any), but we CAN actively exhale and do after exercise. » Expiration • Diaphragm & external intercostals relax, reducing the chest cavity and the lung capacity. • Causes a increase in pressure within the lungs. How does the process of breathing help • Air rushes into the lungs. the cardiovascular system? Inspiration & Expiration

» Breathing rate is controlled by respiratory centers in the pons and medulla. » There is a ‘normal’ rate of inspiration (12 -15 breaths / min) maintained by self-exciting cells » Many sensory inputs act to increase or decrease this normal • Low O 2 ↑ • High CO 2 ↑ • Low blood p. H ↑ • Irritants/stretch ↑ • High body temp ↑ • Emotions ↑↓ • Volition ↑↓ Revisit Do Now – How is breathing regulation similar to and different from heart beat regulation? Usually, Our body is more sensitive to CO 2 / blood p. H levels than to O 2 Regulation of Breathing

Chronic Obstructive Pulmonary Disorder » 3 rd or 4 th leading cause of death (after heart disease and cancer, about tied with stroke) COPD is strongly associated with smoking, but it can » Inability of air to get to capillaries of lungs also be caused by air » Two major diseases associated with COPD pollution • Chronic bronchitis – inflammation of bronchi & excessive mucus production • Emphysema – destruction of alveoli How does each disease reduce gas exchange? COPD

Shortness of breath Enlargement of right side of heart COPD is also characterized by high CO 2 levels – so high, that overtime, the body starts to ignore that information and focus on O 2 levels

Pulmonary rehabilitation breathing exercises Surgery removal of part of the lungs or lung transplant COPD

1. What were our objectives and what did you learn? 2. How does this relate to our unit question? (How do body systems work together? ) 3. How did we demonstrate our learner profile trait? Closure