The Respiratory System

To Review… Cellular Respiration is… A set of chemical reactions that release energy from food molecules aerobic – uses oxygen & releases 36 ATPs anaerobic – does not use oxygen & releases only 2 ATPs (per molecule of glucose)

The Human Respiratory System… FUNCTION: a network of passages that allow gases to pass from the external environment to the internal surfaces of the lungs

Organization of the Respiratory System Nostrils #1 Nasal Cavity #2 Pharynx (throat) #3 Epiglottis #4 Larynx (voicebox) #5 Esophagus #6 Trachea (windpipe) #7 Lung #8 Bronchi #10 Bronchioles #11 Diaphragm #12 Alveoli #13 Alveolus (air sac) #14

Nasal Cavity - exposed to air through nostrils - lined with cilia (minute hairs) & mucous membranes which filter, warm & moisten air

Nasal Cavity

Pharynx (throat) Where the oral and nasal cavity meet Contains the LARYNX –vocal cords (laryngitis is when you lose your voice) (sometimes it protrudes as the Adams apple) Larynx Video

Trachea (windpipe) Kept open by rings of cartilage Cilia and mucus line the trachea & trap microscopic particles Cigarette smoke & other pollutants interfere with the cilia Food is prevented from entering by the epiglottis

A laryngectomy may result from laryngeal cancer, so… DON’T SMOKE!

Bronchi 2 main branches of the trachea Lined with mucus and ringed with cartilage

Bronchioles Many subdivisions (branches) of the bronchi Lined with mucus NO rings of cartilage (during asthma these close up causing wheezing)

Alveoli (air sacs) respiratory surface where O2 and CO2 are exchanged through diffusion at the ends of the bronchioles Thin and moist Surrounded by capillaries Oxygen enters the capillaries from the alveoli CO2 leaves the capillaries and enters the alveoli to be exhaled

Video Gas Exchange CO2 Transport

Lungs Spongy tissue including bronchioles and all alveoli!

Diaphragm Muscle that separates the thorax and the abdomen Contracts and flattens when you inhale Relaxes and curves up when you exhale Breathing Video Why Do We Yawn? - YouTube

Rib Cage Muscles & Chest cavity Inhaling – rib cage (intercostal) muscles contract and chest cavity enlarges (lowering pressure in the lungs so air rushes in) Exhaling – rib cage muscles relax and compressed air is exhaled

What controls your breathing rate? breathing rate is regulated by the concentration of CO2 and its effect on the medulla (part of the brain) increased CO2 medulla causes increase in breathing rate

Dog hiccups??

Malfunctions of the Respiratory System…

1. Pneumonia effect: Fluid develops in the alveoli cause: bacteria or viral infection which persists when immune system is compromised symptoms: fever, chills, fatigue & excessive cough with mucus treatments: antibiotics &rest, wash hands often Video

2. Bronchitis video effect: Inflammation of the bronchial tubes cause: cigarette smoke, air pollution, dust, toxic gases, viruses symptoms: cough, mild fever, tiredness, wheezing treatments: avoid irritants, drink liquids, rest

3. Asthma VIDEO effect: muscular walls of the bronchioles contract and constrict, excess mucus is produced cause: triggered by an allergic response or excess smoke, dust, or stress symptoms: Difficulty breathing, chronic cough treatments: Inhaler or nebulizer, anti- inflammatory drugs

4. Emphysema VIDEO effect: the breakdown of alveoli walls and loss of elasticity of lungs cause: 80% of cases due to smoking, air pollution symptoms: chronic cough, shortness of breath treatments: no cure! oxygen therapy, stop smoking to slow progression

How are the respiratory systems of the following organisms different from that of humans? -Birds -Fish -Insects