How are the respiratory and circulatory system connected

How are the respiratory and circulatory system connected?

Organs of the respiratory system • Nose-internal hairs and mucus pick up unwanted materials – FYI-remember anthrax? Those particles are small enough to get past these hairs – This bacteria releases toxins that cause death • Sinuses-reduce weight of skull and effect voice quality • Pharynx-throat (food travels from mouth to esophagus) produces sounds of speech

• Larynx-conducts air in and out of trachea and prevents foreign objects from entering the trachea; houses vocal cords (made of muscle and elastic fibers) • Trachea-windpipe; split into the left and right bronchi • Bronchial tree-tubes leading into the air sacs – Bronchioles – Alveolar sacs (made of alveoli) • Lungs-contain air passages and alveoli – Right is bigger than the left.

Inspiration vs. Expiration Inspiration Expiration • Pressure is low in lungs and alveoli • Atmospheric pressure pushes outside air INTO airways • Diaphragm contracts and moves down • Lungs expand to fill with air • Increase in lung and alveoli pressure • Atmospheric pressure pushes air OUT of the airways • Diaphragm relaxes and pushes back to position (moves up) • Air moves out of lungs • Returning to original shape

Respiratory Air Volume and Capacities • Respiratory cycle-1 inspiration and 1 expiration • 4 distinct air volumes – Tidal volume-air that moves in (or out) during a single respiratory cycle (500 m. L) – Inspiratory reserve volume-extra volume that enters during forced inspiration (3000 m. L) – Expiratory reserve volume-extra volume that is forced out (1100 m. L) – Residual volume-left over volume after maximal expiration

• Vital capacity-maximum amount of air a person can exhale after taking the deepest breath possible – IRV + TV + ERV • Inspiratory capacity-maximum volume of air a person can inhale following exhalation of the tidal volume – TV + IRV • Functional residual capacity-volume of air that remains in the lungs after a person exhales the tidal volume • Total Lung Capacity-Vital capacity + residual volume

What controls breathing? • Pons and medulla oblongata -The inspiratory area determines the basic rhythm and is also responsible for the contraction of the diaphragm. -The expiratory center is usually inactive during normal respiration, however during forceful expiration e. g. during exercise, it is activated by nerve impulses from the inspiratory area. muscles, resulting in a forced expiration. • Pneumotaxic area regulates breathing rate. – Part of the pons – Helps to facilitate expiration.

Factors that control breathing • Chemoreceptors – Stimulate these and increase breathing – Stimulated by blood concentration of carbon dioxide and hydrogen ions • Chemoreceptors in arterial walls – Sense low oxygen concentration • Overstretching of lungs triggers an inflation reflex. – Prevent overinflation of lungs

Gas Exchange in the Lungs

Alveolar Gas Exchange • Respiratory membrane-two layers of epithelial cells and a basement membrane that separates the blood from the alveolar gases • Gases move due to partial pressure • Oxygen and carbon dioxide move from high pressure to a low pressure -diffusion – Many factors effect this: surface area and solubility of gases (emphysema reduce the surface area so oxygen isn’t exchanged as well)

Gas Transport-Oxygen • Oxygen that blood transports is attached to hemoglobin (iron containing protein)-forms oxyhemoglobin – They do not form a strong bond so hemoglobin releases oxygen easily so it can diffuse into the cells • RELEASES IN AREAS WHERE PRESSURE OF OXYGEN IS LOW (diffusion) – How much oxygen will oxyhemoglobin release? • Carbon dioxide levels increases • Blood temperature increases • p. H of blood decrease (acid) • Hypoxia-deficiency of blood in the tissues – Decreased arterial pressure (hypoxemia), inadequate blood flow (ischemic hypoxia), lack ability to transport blood (anemic hypoxia), or a defect at the cell

Gas Transport-Carbon Dioxide • Transported back to the lungs as: dissolved in plasma (7%), binds to hemoglobin, form of bicarbonate ion • Bind with hemoglobin called carbaminohemoglobin (23%) • Most common form-bicarbonate ion (70%) – Carbon dioxide reacts with water to form carbonic acid (carbonic anhydrase speeds this up) – This will dissociate to form H+ and bicarbonate ions • At the lungs, dissolved carbon dioxide enters the alveoli; bicarbonate ion and hydrogen recombine to form carbonic acid but quickly breaks down into carbon dioxide and water

What do we breathe out? BREATHE OUT • 4 -5% is Carbon dioxide • 17 -18% is oxygen • 74. 9% is inert nitrogen gas • 6. 2% is water • • • BREATHE IN 21% oxygen 0. 04% carbon dioxide 78% nitrogen 0. 5% water

How does smoking effect this? • The normal percent of hemoglobin that bind to CO (carbon monoxide) is 2% • Smokers may exceed 20% • Increased levels prevent oxygen from binding, starving tissues of oxygen, and causing chest pains, shortness of breath, fatigue, confusion, and abnormal heart rhythm

Common disorders • Asthma-destruction of airwayss • Emphysema • Bronchitisalveolar walls lose inflammation of the elasticity and bronchi remained filled with • Pneumoniaair during exhale infection or (lungs become inflammation of permanently alveoli/fill up with inflated) fluid and dead wbc

Common disorder • Tuberculosis-caused by bacteria (mycobacterium tuberculosis); destroys lung tissue and is replaced by tough fibrous tissue • Lung cancer-bronchogenic carcinoma – Starts in bronchial walls – Goblet cells get bigger and secrete more mucus – Other cells divide and take up more space