Respiratory and Circulatory Functions Lecture #8 Ms. Day/ Honors Biology

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  O 2 and CO 2 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 (O 2 ) into the body and remove waste gases (CO 2 ) out of the body Main job of Circulatory System  Moves blood to all parts of the body. Get oxygen (O 2 ) into the body and remove waste gases (CO 2 ) out of the body These systems work together!

Where do the gases come from? Why do we need them? Cellular Respiration : creates ATP from food O 2 = Needed for cellular respiration to make ATP (energy)  You breath in O 2 from air CO 2 = waste product The overall process is: Macromolecules + O 2  CO 2 + H 2 O + 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

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 External Respiration Pathway

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 to be swallowed

Pathway of Air into the Body (continued) 3. Enters a series of tubes  Protected by cartilage to keep tubes firm/open 1 st = Enters trachea which branches out into 2 nd = 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.

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

Recall: Gas Exchange 3 principles for gas exchange: O 2 and CO 2 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 O 2 concentration is higher in alveoli than blood  oxygen diffuses into blood At body cells, O 2 concentration is higher in blood  oxygen diffuses out of blood and into cells

Gas Exchange O 2  alveoli  capillaries  red blood cells CO 2  red blood cells  capillaries  alveoli 

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 CO 2 !!  7% of CO 2 transported as dissolved CO 2 in blood plasma (water portion of blood)  23% binds to hemoglobin  70% transported in the form of bicarbonate ions (HCO 3 - ) CO 2 (g) + H 2 0 (l)  H + + H CO 3 -

Oxygen/Carbon Dioxide Transport 1. O 2 diffuses from alveoli to blood 2. Blood travels to heart and body 3. In tissues, O 2 levels are lower, so RBCs release O 2 to cells 4. In tissues, CO 2 levels are higher, so CO 2 diffuses from cells to blood 5. CO 2 travels in blood to heart 6. Heart pumps blood to lungs where CO 2 is released REMEMBER: TOO MUCH CO 2 CAUSES BLOOD  ACIDIC!

WHY DOES BLOOD BECOMES ACIDIC WITH TOO MUCH CO 2 ? CO 2 causes blood to become ACIDIC because:  CO 2 (g) + H 2 0 (l)  H + + HCO 3 - Lots of CO 2 indicates lots of cell respiration  need for O 2 Control centers in brain regulate Called Medulla oblongata and pons Maintain homeostasis by monitoring CO 2 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 ent_view0/chapter25/animation__gas_exchange_during _respiration.html ent_view0/chapter25/animation__gas_exchange_during _respiration.html  Complete the quiz questions 1-5 after we’ve watched the animation

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