Respiratory System Ms. Day AP Biology https://www.youtube.com/watch?v=hc1YtXc_84A

Circulatory and Respiratory Systems They work together to help maintain homeostasis in the body. What do they help to regulate? Body temp Heart rate Breathing rate O2 and CO2 levels in cells

Function of Respiratory and Circulatory Systems Main job of Respiratory System Transport gases to and from the circulatory system What gases? Get oxygen (O2) into the body and remove waste gases (CO2) out of the body Main job of Circulatory System Moves blood to all parts of the body. These systems work together!

Where do the gases come from? Why do we need them? Cellular Respiration: creates ATP from food O2 = Needed for cellular respiration to make ATP (energy) You breath in O2 from air CO2 = waste product The overall process is: Macromolecules + O2  CO2 + H2O + energy (ATP) Carbohydrates, fats, and proteins can all be used as the fuel, but most useful is glucose.

Respiratory and Circulatory Systems Components of Respiratory Nose Mouth Pharynx Trachea Lungs Diaphragm Components of Circulatory Heart Blood Blood Vessels Arteries Veins Capillaries

Respiratory System (in detail)

RESPIRATORY SYSTEM https://www.youtube.com/watch?v=AJpur6XUiq4

External Respiration Pathway Respiratory surface = the exchange of gases between the atmosphere and the blood (entirely dependent on diffusion!!!) Movement of substance from high concentration to low concentration Mucous membranes are found through the respiratory system thin, warm and moist  needed for diffusion

Pathway of Air into the Body 1. Nose/Mouth-external opening to allow entry Air is filtered, cleaned, warmed, moistened 2. Air moves through pharynx to trachea Trachea (windpipe) traps the inhaled particles with cilia and mucus Mucus traps foreign particles Cilia “sweep” foreign material away from lungs then swallowed Impurities in air, such as dirt and bacteria, are filtered by hair and mucus in the nose. The air is warmed and moisture is added.

Pathway of Air into the Body (continued) 3. Enters a series of tubes Protected by cartilage to keep tubes firm/open 1st = Enters trachea which branches out into 2nd = two bronchi that also branches out into even smaller tubes called bronchioles 4. Bronchioles end up in air sacs called alveoli, where all exchange of gases occur. Impurities in air, such as dirt and bacteria, are filtered by hair and mucus in the nose. The air is warmed and moisture is added.

Structure of Alveoli (ends of bronchioles) Small air sacs covered in mucus Wrapped in tiny blood vessels called capillaries 300 to 600 million in a pair of lungs Great deal of surface area Actual site of gas exchange

How do we breath? Involves muscles of the rib cage and the diaphragm Diaphragm: dome shaped skeletal muscle at the base of the rib cage Inhale (take air into lungs) muscles contract, expand rib cage, diaphragm moves down Exhale (release air from lungs) muscles relax, contract rib cage, diaphragm moves up

Ventilation (Inhalation/Exhalation) Diagram V P V P

Recall: Gas Exchange 3 principles for gas exchange: O2 and CO2 are carried by the blood Opposite directions Gas moves by diffusion (moves from area of high to low concentration) Lining of the alveoli must be moist to help gases diffuse

Diffusion of gases Gases always move from areas of high concentration to areas of low concentration O2 concentration is higher in alveoli than blood oxygen diffuses into blood At body cells, O2 concentration is higher in blood oxygen diffuses out of blood and into cells

Gas Exchange O2  alveoli  capillaries  red blood cells CO2 red blood cells  capillaries  alveoli  Inhaled oxygen dissolves in the film of moisture on the alveoli cells. Oxygen then diffuses into a web of capillaries surrounding each alveolus and enters red blood cells, binding with red blood cells. Carbon dioxide diffuses the opposite way, from the capillaries across into the alveoli. Then the carbon dioxide is expelled back up the trachea, through the nose or mouth out into the air.

Hemoglobin and Gas Exchange Oxygen diffuses into red blood cell (RBC’s) where there is hemoglobin (a protein in RBC) Hemoglobin contain iron atoms, which bind to oxygen gas

Carbon Dioxide Transport Hemoglobin ALSO helps transport CO2!! 7% of CO2 (in plasma) transported as dissolved CO2 in blood plasma (water portion of blood) 23% binds to hemoglobin (in RBC’s_ 70% (inside RBC’s) transported in the form of bicarbonate ions (HCO3-) CO2 (g) + H20 (l)  H+ + HCO3-

Oxygen/Carbon Dioxide Transport O2 diffuses from alveoli to blood Blood travels to heart and body In tissues, O2 levels are lower, so RBCs release O2 to cells In tissues, CO2 levels are higher, so CO2 diffuses from cells to blood CO2 travels in blood to heart Heart pumps blood to lungs where CO2 is released REMEMBER: TOO MUCH CO2 CAUSES BLOOD  ACIDIC! The altered shape makes it easier for the Hb to give up the oxygen

WHY DOES BLOOD BECOMES ACIDIC WITH TOO MUCH CO2? CO2 causes blood to become ACIDIC because: CO2 (g) + H20 (l)  H+ + HCO3- Lots of CO2 indicates lots of cell respiration  need for O2 Control centers in brain regulate Called Medulla oblongata and pons Maintain homeostasis by monitoring CO2 level Main cue is pH change in blood

Gas Exchange and the Nervous System What happens when you exercise? Start breathing faster Heart beats faster Why? Your muscles cells are running out of oxygen, so the heart and lungs have to work harder to deliver the necessary oxygen The rate of respiration is controlled by automatic regulators in your brain stem (medulla and pons) Stimulates nerves in the diaphragm and ribcage to breathe harder and faster

Gas Exchange Animation http://highered.mheducation.com/sites/0072495855/student_view0/chapter25/animation__gas_exchange_during_respiration.html Complete the quiz questions 1-5 after we’ve watched the animation for review. https://www.youtube.com/watch?v=VINQnL_oVFY

Health of Respiratory System Diseases can interfere with gas exchange Pneumonia Caused by virus or bacteria, Inflammation of alveoli Weak and tired due to less oxygen exchange Bronchitis Caused by bacteria or virus (cold or flu), Inflammation of bronchi Cough to clear excess mucus

Health of Respiratory System Asthma May be allergic, response to stress, etc. Narrowed breathing passages (bronchi) Treated with drugs that relax air passages Emphysema Lung disorder usually caused by smoking Alveoli are destroyed and cells can’t get enough oxygen

Cancer and emphysema