Organization of the Respiratory System The upper respiratory system consists of the nose, nasal cavity, paranasal sinuses, and pharynx (throat). These passageways filter, warm, and humidify incoming air, protecting the more delicate surfaces of the lower respiratory system. They also cool and dehumidify outgoing air. The lower respiratory system includes the larynx (voice box), trachea (windpipe), bronchi, bronchioles, and alveoli of the lungs.

Human Respiratory System

STRUCTUREFUNCTION nose / nasal cavity warms, moistens, & filters air as it is inhaled pharynx (throat) passageway for air, leads to trachea larynx the voice box, where vocal chords are located trachea (windpipe) trachea is lined with fine hairs called cilia which filter air before it reaches the lungs bronchi two branches at the end of the trachea, each lead to a lung bronchioles a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs alveoli the functional respiratory units in the lung where gases are exchanged Organs in the Respiratory System

Lungs Left lung divided into 2 lobes smaller than the right lung Right lung divided into 3 lobes

Components of the Upper Respiratory Tract

Components of the Lower Respiratory Tract

Respiratory System Functions 1.supplies the body with oxygen and disposes of carbon dioxide 2.filters inspired air 3.contains receptors for smell 4.rids the body of some excess water and heat 5.helps regulate blood pH

What is Human Respiration? The human respiratory system allows one to obtain oxygen, eliminate carbon dioxide. The Respiratory System helps you breathe. When the human body breathes air, it gets sucked through the nostrils or the mouth. Then it goes through the trachea (wind pipe). The trachea divides into tubes called bronchi which carry the air on to each lung.

Respiration Breathing consists of two phases, inspiration and expiration Inspiration- the process of taking in air Expiration- the process of blowing out air

Respiration Mechanics of breathing – Pulmonary ventilation includes two phases called inspiration (movement of air into lungs) and expiration (movement of air out of lungs) – Changes in size and shape of thorax cause changes in air pressure within that cavity and in the lungs because as volume changes, pressure changes in the opposite direction – Air moves into or out of lungs because of pressure differences (pressure gradient); air moves from high air pressure toward low air pressure

Respiration Inspiration – Active process—muscles increase volume of thorax, decreasing lung pressure, which causes air to move from atmosphere into lungs (down the pressure gradient) Diaphragm flattens during inspiration—increases top- to-bottom length of thorax External intercostals—contraction elevates the ribs and increases the size of the thorax from front to back and from side to side

Respiration Expiration – Reduction in the size of the thoracic cavity decreases its volume and thus increases its pressure, so air moves down the pressure gradient and leaves the lungs – Quiet expiration ordinarily a passive process – During expiration, thorax returns to its resting size and shape – Elastic recoil of lung tissues aids in expiration

Respiration Expiration – Internal intercostals and abdominal muscles— expiratory muscles used in forceful expiration Internal intercostals—contraction depresses the rib cage and decreases the size of the thorax from front to back Abdominal muscles—contraction elevates the diaphragm, thus decreasing size of the thoracic cavity from top to bottom

Moving air in and out

Exchange of Gases Exchange of gases in lungs – Carbaminohemoglobin breaks down into carbon dioxide and hemoglobin – Carbon dioxide moves out of lung capillary blood into alveolar air and out of body in expired air – Oxygen moves from alveoli into lung capillaries – Hemoglobin combines with oxygen, producing oxyhemoglobin

Exchange of Gases Exchange of gases in tissues – Oxyhemoglobin breaks down into oxygen and hemoglobin – Oxygen moves out of tissue capillary blood into tissue cells – Carbon dioxide moves from tissue cells into tissue capillary blood – Hemoglobin combines with carbon dioxide, forming carbaminohemoglobin

Oxygen Exchange

Malfunctions & Diseases of the Respiratory System Asthma Asthma is characterized by spastic contraction of the smooth muscle in the bronchioles, which partially obstructs the bronchioles and causes extremely difficult breathing. Bronchitisinflammation of the lining of the bronchioles Emphysema condition in which the alveoli deteriorate, causing the lungs to lose their elasticity Pneumonia condition in which the alveoli become filled with fluid, preventing the exchange of gases Lung cancer irregular & uncontrolled growth of tumors in the lung tissue