Bellringer 10/28/15 1. What is the function of the heart? 2. What is the function of the lungs? 3. How do they work together to maintain homeostasis? 1

2 Respiratory and Circulatory Functions Sections 30.1 – 30.2

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 3

4 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.  Get oxygen (O2) into the body and remove waste gases (CO2) out of the body These systems work together!

Respiratory and Circulatory Systems Components of Respiratory  Nose  Mouth  Sinus  Trachea  Lungs  Diaphragm  Pharynx  Alveoli  Bronchi and Bronchioles Components of Circulatory  Heart  Blood  Blood Vessels Arteries Veins Capillaries 5

6 RESPIRATORY SYSTEM

7 Pathway of Air into the Body Nose and Mouth-external opening to allow entry  Air is filtered, cleaned, warmed, moistened Enters a series of tubes  Protected by cartilage to keep tubes firm/open  Mucus--traps foreign particles  Cilia-- “sweep” foreign material away from lungs to be swallowed (or spit/coughed)

8 Structure of Alveoli Small air sacs covered in mucus. Wrapped in tiny blood vessels called capillaries

9 Respiratory System = system of tubes Trachea--main passageway to lungs Bronchi--two branches off the trachea that lead to lungs Bronchioles--smaller branches of the bronchi that lead to alveoli Alveoli--small air sacs at end of bronchioles  300 to 600 million in a pair of lungs  Great deal of surface area  Actual site of gas exchange

Breathing Mechanisms Involves muscles of the rib cage and the diaphragm Diaphragm: dome shaped muscle at the base of the rib cage  Inhale: muscles contract, expand rib cage, diaphragm moves down  Exhale: muscles relax, contract rib cage, diaphragm moves up 10

Breathing Mechanisms 11 Air exhaled Rib cage lowers Diaphragm Exhalation Air inhaled Rib cage rises Diaphragm Inhalation

Gas Exchange 3 principles for gas exchange: O2 and CO2 are carried by the blood Gas moves by diffusion (moves from area of high to low concentration) Lining of the alveoli must be moist to help gases diffuse 12

13 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

14 Gas Exchange Oxygen  alveoli  capillaries  red blood cells Carbon Dioxide  red blood cells  capillaries  alveoli 

15 Oxygen/Carbon Dioxide Transport 1. O 2 diffuses from alveoli to capillaries. 2. O 2 rich blood travels to heart and pumped to the body 3. In tissues, O 2 levels are lower, so Red Blood Cells 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 in form of Bicarbonate ions (HCO 3 - ) 6. Heart pumps blood to lungs where HCO 3 - breaks down to CO 2 and water and then expelled out of body.

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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 17

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19 Cancer and emphysema

20 Circulatory System in detail Sections 30.3 – 30.5

21 CIRCULATORY SYSTEM

22 Circulatory System Functions Carry O 2 to cells and CO 2 away from cells Deliver nutrients through body (after absorption in small intestine) Carry wastes away from cells (H 2 O, salt, urea) Help in fighting infections Temperature regulation

Parts of Circulatory System Heart: muscular pump that keeps blood moving throughout the system Blood: contains fluids, red blood cells, white blood cells, and platelets Blood vessels: carry blood to all of the body cells 23

Types of Blood Vessels Arteries: carry blood away from heart Veins: carry blood back to heart Capillaries: tiny blood vessels that deliver O2/remove CO2 from body cells 24

The Heart The heart is a muscular pump containing 4 chambers Made of special cardiac muscle that does not tire, unlike other muscles 2 smaller chambers at the top called atria (singular atrium) 2 larger chamber at the bottom called ventricles There are valves separating all of the chamber that prevent backflow 25

26 Chambers of the Heart

27 Two main circuits Pulmonary  Blood goes from heart to lungs to pick up oxygen and release carbon dioxide Systemic  Blood pumped out of heart to the rest of the body  Sound of heart (lub/dub) made by valves closing

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29 Blood flow through the heart 1. Into vena cava 2. Into right atrium 3. Down to right ventricle 4. Out pulmonary artery to lungs ¨ Gets O 2 and dumps CO 2 5. Back to heart through pulmonary vein 6. Into left atrium 7. Down to left ventricle 8. Out aorta to body

31 Blood flow through the body Blood vessels  Arteries--take oxygenated blood away from the heart Thick/muscular and flexible walls Do not contain valves High Pressure

32 Blood flow through the body Capillaries Very small vessels  Gases diffuse across very thin wall of small vessels  Nutrients and oxygen leave the blood and go into the body tissue

33 Blood flow through the body Blood vessels  Veins--take deoxygenated blood back to the heart Thin walls Larger diameters than arteries Have one-way valves Low Pressure

34 Blood flow through rest of body

Circulation and Blood Pressure Blood Pressure: the forces with which blood pushes against the wall of an artery Healthy BP is 120/70  Systolic is top number, when the left ventricle contracts  Diastolic is bottom number, when the left ventricle relaxes What could cause high BP?  Blocked arteries  Less elastic arteries  Stress, high activity 35

36 Function: Delivery of nutrients and removal of wastes Blood delivers O 2 to cells Delivers nutrients from digestion to cells (sugars, proteins) Blood takes CO 2 back to lungs Delivers salts, water, and nitrogenous wastes (urea) to the kidneys for excretion  Urea Main nitrogenous waste of body Produced in liver (from ammonia--NH 3 ) Removed by kidneys

Function: Homeostasis (Maintain Temperature) In cold environments, blood vessels constrict in extremities to keep the torso and brain warm. In hot environments, blood vessels dilate and release excess heat. 37

Function: Homeostasis (Maintain Oxygen Levels) When cells need more oxygen, sensors in the walls of major arteries send signals to brain stem (medulla) Medulla coordinates with respiratory and circulatory systems to increase oxygen flow to cells and maintain homeostasis 38