Respiratory System Respiratory System Pathway of Air Nosemouth

Respiratory System

Respiratory System Pathway of Air: • Nose/mouth • Nasal/oral cavities • Pharynx • *Epiglottis • Larynx • Trachea • Bronchioles • Alveoli

Oral & Nasal Cavities & Pharynx • Warm & moisten air to protect delicate lung tissue. • Sticky mucous lining & mucous-covered hairs in nasal cavity filter particles from air.

Larynx & Voice • Sound produced as 2 ligaments (vocal cords) vibrate when air passes through them. • Pitch varies with tension of vocal cords – more tension = higher pitch • Volume depends on amount of air forced past them – more air = greater volume. • Laryngitis – inflammation of vocal cords due to overuse.

Lungs • Right is larger (3 lobes) than left (2 lobes). • In thoracic cavity, lined w/ pleura (membranes that reduce friction. • LARGE surface area. Trachea/bronchi • Made of rings of cartilage (keeps airway open). • Lined with mucous membranes (trap particles) and cilia (sweep particles up and out of airway). • Epiglottis closes trachea when swallowing. • Bronchi branch into bronchioles Airway

Alveoli & Capillaries Bronchioles terminate in dead-end sacs – alveoli – surrounded by a net of capillaries. Respiratory System - Khan Academy

Gas Exchange • External Respiration Exchange of gases between atmosphere and blood by diffusion. • Internal Respiration – Exchange of gases between blood and cells by diffusion. • Diffusion happens when there is a concentration gradient (difference) in a fluid (gas or liquid). • *The Respiratory System • Respiratory System

97% of oxygen transported on hemoglobin in RBCs. 67% of CO 2 reacts w/ water to form carbonic acid, disassociates into bicarbonate ions (HCO 3 -) Oxygen & CO 2 Transport In Blood

Mechanism of Breathing • Diaphragm • Mechanism of Breathing • Mechanics of Breathing 2 Boyle’s Law – pressure exerted by a gas varies inversely with the volume of the gas.

Inspiration & Expiration Respiratory System Review - Kahn Academy

Regulation of Breathing Q. Brain monitors the concentration of CO 2 in the blood. Why not O 2? A: O 2 is carried by hemoglobin inside RBCs, while CO 2 is mostly carried in the plasma.

Disorders • Asthma – inflammation of the lining of bronchioles causes reduced air flow. • Emphysema – alveoli lose elasticity and rupture, reducing surface area and lung capacity.

Smoking • Tar and particles clog up lungs & paralyze cilia so they can’t clear debris. • If a smoker quits, damage may be reversible.