Human Respiratory Human Respiratory SystemSystem

Aim: How does your body undergo Aim: How does your body undergo respiration?respiration?

Function of the Respiratory Function of the Respiratory SystemSystem

A.A. Allows Allows gas exchangegas exchange between the between the external environmentexternal environment and and internal internal environmentenvironment..

B.B. Cilia and mucus membranesCilia and mucus membranes line all the line all the internal walls of the internal walls of the respiratory tractrespiratory tract..

C.C. Works closely with the Works closely with the circulatory circulatory systemsystem..

Respiratory

Tract

Structures of the Respiratory Structures of the Respiratory SystemSystem

A.A. Nose — Nose — air entersair enters through through nostrilsnostrils and and passes into passes into nasal cavitynasal cavity..1. Air is 1. Air is filtered, warm & moistenedfiltered, warm & moistened..

B.B. Air moves past the Air moves past the pharynx pharynx

(throat) into (throat) into larynxlarynx (voice box) (voice box)

that contains vocal cords.that contains vocal cords.

Upper Respiratory tract

Structures of the Respiratory Structures of the Respiratory SystemSystem

C.C. Trachea (Trachea (windpipewindpipe) — tube that has ) — tube that has cartilage ringscartilage rings..1. Lined with 1. Lined with mucus to trap dust, pollen & mucus to trap dust, pollen & microbesmicrobes..2. Tracheal cells have 2. Tracheal cells have ciliacilia that move that move trapped trapped particles towards the pharynxparticles towards the pharynx by the beating by the beating cilia.cilia.3. Cartilage rings surround trachea to 3. Cartilage rings surround trachea to keep it keep it openopen..

Structures of the Respiratory Structures of the Respiratory SystemSystem

D.D. Bronchi (Bronchi (two cartilage tubestwo cartilage tubes) — the ) — the trachea splits into the trachea splits into the right & left right & left bronchibronchi, each of which , each of which enters the enters the lungslungs..1. Looks like an inverted “Y”.1. Looks like an inverted “Y”.

2. Splits into 2. Splits into smaller and smaller tubessmaller and smaller tubes called called bronchial tubesbronchial tubes..3. Bronchial tubes 3. Bronchial tubes subdividesubdivide into smaller and into smaller and smaller branches called smaller branches called bronchiolesbronchioles..

Structures of the Respiratory Structures of the Respiratory SystemSystem

E.E. Bronchioles — Bronchioles — small tubes that are small tubes that are lined with mucuslined with mucus but but do notdo not have have cartilage rings.cartilage rings.

1. They subdivide and 1. They subdivide and end in alveoliend in alveoli..

Structures of the Respiratory Structures of the Respiratory SystemSystem

F.F. Alveoli — also celled Alveoli — also celled air sacsair sacs & are the & are the functional unit of the lungsfunctional unit of the lungs..

1. Site of 1. Site of gas exchangegas exchange..

2. 2. One cell layer thickOne cell layer thick, moist & surrounded by , moist & surrounded by capillariescapillaries..

3. Capillaries transport 3. Capillaries transport deoxygenated blooddeoxygenated blood to to the alveoli. the alveoli.

4. 4. COCO22 leaves leaves and and OO22 is picked up is picked up..

Alveoli

Structures of the Respiratory Structures of the Respiratory SystemSystem

G.G. Lung — Lung — made up of the bronchial made up of the bronchial tubes, bronchioles & alveolitubes, bronchioles & alveoli..

H.H. Diaphragm — Diaphragm — musclemuscle that forms the floor that forms the floor of the chest cavity.of the chest cavity.

Gas ExchangeGas Exchange

A.A. After inhalation, high concentration of After inhalation, high concentration of OO22

diffuses into the bloodstreamdiffuses into the bloodstream by by capillaries.capillaries.

B.B. Hemoglobin in RBC’s carry the Hemoglobin in RBC’s carry the OO22 as as

oxyhemoglobinoxyhemoglobin..

HbHb ++ OO22 HbOHbO22

Hemoglobin Hemoglobin OxygenOxygen OxyhemoglobinOxyhemoglobin

Gas ExchangeGas Exchange

C.C. After exhalation, after cellular respiration After exhalation, after cellular respiration cells produce a cells produce a high concentration of high concentration of COCO22..

D.D. Hemoglobin in RBC’s carry the Hemoglobin in RBC’s carry the COCO22 to to

the lungs as a bicarbonate (HCOthe lungs as a bicarbonate (HCO33).).

COCO22 ++ HH22OO HCOHCO33

Carbon dioxideCarbon dioxide WaterWater BicarbonateBicarbonate

BreathingBreathing

Moves air into and out of the lungs.Moves air into and out of the lungs.

A.A. Inhalation:Inhalation:

1. 1. Ribs move up & outRibs move up & out..

2. Diaphragm moves 2. Diaphragm moves downdown..

3. This 3. This increasesincreases the volume the volume

of the chest cavity which of the chest cavity which fillsfills

the lungs with airthe lungs with air..

Breathing

B. Exhalation:1. Ribs move down & in.

2. Diaphragm moves up.

3. This forces air out of

the lung.

Breathing

Breathing

C. Breathing is regulated by the brain which is sensitive to the concentration of CO2 in the blood.

D. When CO2 level rises breathing rate increases.

Disorders of the Respiratory System

A. Bronchitis — inflammation of the bronchial tubes.

B. Asthma — allergic reaction characterized by the constriction of the bronchial tubes which causes difficulty breathing.

Disorders of the Respiratory System

C. Emphysema — enlargement & degeneration of the alveoli which results in a decreased lung capacity. Lungs lose elasticity.

D. Pneumonia — alveoli become filled with fluid & prevents the exchange of gases.

Pneumonia

Emphysema

Disorders of the Respiratory Disorders of the Respiratory SystemSystem

E.E. Lung Cancer — Lung Cancer — tumors form in the lungtumors form in the lung due to uncontrolled cell division.due to uncontrolled cell division.