3.2 Respiratory System

What is Human Respiration? The human respiratory system allows one to obtain oxygen, and eliminate carbon dioxide. Breathing consists of two phases, inspiration and expiration Inspiration- the process of taking in air Expiration- the process of blowing out air

Functions of the Respiratory System Breathing process Exchange of Oxygen and Carbon Dioxide Enable speech production

Internal Respiration All cells require oxygen for metabolism All cells require means to remove carbon dioxide Gas exchange at cellular level

External Respiration Ventilation Gas Exchange in pulmonary capillaries exchange of air between lungs and atmosphere Gas Exchange in pulmonary capillaries Breathing largely involuntary activity

Structure and Function Gas exchange Bringing oxygen into the body Getting rid of carbon dioxide

Organs in the Respiratory System STRUCTURE FUNCTION 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)  keeps the windpipe "open"  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

Nose nasal cavity nasal septum mucous membrane mucus cilia olfactory receptors

Pharynx Nasopharynx oropharynx laryngopharynx adenoids or pharyngeal tonsils oropharynx palatine tonsils laryngopharynx larynx

Epiglottis oropharynx and laryngopharynx serve as a common passageway for both food and air epiglottis acts as a lid or flap that covers the larynx and trachea (airway) so food does not enter the lungs.

Larynx voice box larynx glottis (vocal apparatus) vocal bands or vocal cords

Trachea Windpipe or airway mucous membrane lining with cilia smooth muscle with c-shaped cartilage rings divides into two branches: bronchi no gaseous exchange

Bronchi Bronchus, singular c-shaped cartilage rings with smooth muscle each bronchi divides into bronchioles terminate in air sacs called alveoli

Thoracic Cavity thoracic thorax mediastinum heart aorta esophagus bronchi thymus

Alveoli air sacs alveolar wall membranes one cell thick and surrounded by capillaries gaseous exchange takes place here

Lungs Right-3 lobes Left-2 lobes trachea

Pleura each lung enclosed in pleura parietal pleura (inner) visceral pleura (outer) pleural space or pleural cavity lubricating fluid

Tissues of the Respiratory System epithelial tissue that lines the trachea and bronchi produce mucus (traps dirt). epithelial tissue also has cilia (microscopic hair-like structures) to move mucus and foreign material out. trachea (windpipe) is supported by rings of cartilage (connective tissue) – keeps it open for air to flow freely

Breathing involves the diaphragm (a large sheet of muscle underneath the lungs) and the muscles between the ribs. an involuntary process that we can override while talking but only temporarily controlled by a part of the human brain that detects the concentration of CO2 in our blood

Respiratory Cycle Respiration rate is the number of breaths per minute Human respiration rate is controlled by a part of the brain called the medulla Sends signals to adjust levels of oxygen present in your body by changing your breathing rate

Air Pathway air enters through the nostrils (air is filtered by nose hair) ↓ nasal cavity (air is warmed and humidified) pharynx (throat) larynx (voicebox) trachea (windpipe) bronchi (there are 2, each leads to 1 lung) bronchioles alveoli (clusters of air sacs with a very large surface area, surrounded by capillaries)

Main Parts of the Respiratory System Trachea (windpipe) tube that takes air from the back of the throat down to the lungs

Main Parts of the Respiratory System Bronchi as the trachea approaches the lungs it splits into two bronchi, one bronchus leads to each lung continues splitting into small bronchiole tubes ending in the alveoli Label”: nasal cavity Mouth pharynx trachea Bronchus lung bronchioles

Main Parts of the Respiratory System Alveoli (singular: alveolus) millions of alveoli provide a large total surface area for greater absorption of gases a thin, single layer of flattened cells are on the wall of each alveolus to decrease the distance that gases need to diffuse across a dense network of capillaries (tiny blood vessels) surrounding the alveolus remove CO2 from the blood and absorb O2 Hemoglobin, the protein found in red blood cells, pick up O2 from the alveoli to transport to the rest of the body

Gas Exchange the circulatory system provides a good blood supply the lungs the concentration of O2 in the blood that flows through the lungs is always less than the concentration of O2 in the air in the alveoli, therefore O2 always diffuses from alveoli into the blood. Talk about concentration gradient. Diffusion from area of high concentration to low concentration

Disorders of the Respiratory System

Malfunctions & Diseases of the Respiratory System asthma severe allergic reaction characterized by the constriction of bronchioles  bronchitis inflammation 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

Asthma Some contaminants in some people will trigger inflammation of the airways, i.e. asthma. People with asthma inhale corticosteroids (using “puffers”) to reduce the inflammation.

Tuberculosis (TB) infectious disease – easily spread caused by bacteria in the lungs general symptoms: fever, cough, weight loss, fatigue, and chest pain. diagnosed by a chest X-ray. problem: TB bacteria can remain dormant for many years – waiting for the immune system to be compromised to take over. however, once detected, the disease can be successfully treated with medicine and/or a few weeks hospitalization

SARS (Severe Acute Respiratory Syndrome) disease of the respiratory system symptoms: flu-like (high fever), shortness of breath, dry cough, sore throat, headache, muscle pain, and exhaustion.

Lung Cancer tobacco use – first and second-hand smoking is detrimental to the respiratory system contains carcinogens (cancer-causing chemicals)

HOMEWORK “What is Breathing and Respiration?” Package Pg. 107 #1-5