Respiratory and Circulatory Systems

Objectives 14. I can state the function of the respiratory system 15. Identify where gas exchange occurs 16. Explain how gases move between body cells and alveoli

Major Functions of Respiratory System  Where gas exchange takes place Oxygen (O 2 ) and Carbon Dioxide (CO 2 )

Lungs are the only place where gases from the blood and gases from air are exchanged RED BLOOD CELLS:  - Pick up oxygen from lungs and transports it to cells  - Picks up carbon dioxide from cells and transports it back to lungs

Respiratory Structures  Sinus  Nose  Mouth  Trachea  Lungs  Diaphragm

Gas Exchange occurs in Alveoli  3 key principles: 1. O ₂ and CO ₂ are carried by the blood 2. Lining of alveoli must be moist 3. Gases move by diffusion - move from area of higher concentration to lower concentration

How it works? Capillaries, which carry blood, surround and penetrate alveoli.

O ₂ concentration in alveoli is higher = O ₂ diffuses from alveoli into blood

CO ₂ concentration is higher in blood = CO ₂ diffuses from blood into alveoli

Diaphragm  Muscle that controls breathing Contracts and moves down during inhalation (breathing in) Relaxes and moves up during exhalation (breathing out)

 Meet The Lungs Meet The Lungs

Circulatory System

Your Heart  Beats about 100,000 times a day and circulates all 5 liters of blood every 60 seconds  Diameter of aorta is about the same size around as a garden hose  Human circulatory system is a closed system  Leading cause of death in the US is heart disease

Major Functions of Circulatory System 1. Carries nutrients and wastes 2. Transports gases (carbon dioxide and oxygen) 3. Carries hormones (endocrine) 4. Distributes heat

Structures  4 chambered heart  Valves  Arteries, veins and capillaries  Blood

Heartbeat  SA node gives off an electrical signal that starts wave of contractions  Pacemakers replace SA nodes

‘Roads’ That Carry Blood  Arteries = carry blood away from heart Thick walls, under great pressure  Veins = carry blood to the heart Thin walls; contain valves  Capillaries = networks that move blood in and out of organs and tissue Thin walls allow diffusion in and out of blood

Valves  Flaps of tissue that prevent blood from flowing backward

Pathway of Blood Heart pumps blood twice per cycle First through lungs to add oxygen and remove carbon dioxide Second time to distribute oxygenated blood throughout body

Heart Diseases: leading cause of death in U.S. Arteriosclerosis is when artery walls become thick and inflexible. Arthrosclerosis is when blood flow is partially or fully blocked by plaque. Both diseases can lead to heart attack, stroke or kidney damage

 Your Heart Your Heart  How the Heart Works How the Heart Works

Blood Delivery system = fluids, gases, nutrients, distributes heat, components fight infection and control bleeding Composed of: Red Blood Cells White Blood Cells Platelets Plasma

Red Blood Cells  Function: carry oxygen and carbon dioxide  40-50% of blood composition  Produced from stem cells in bone marrow  Biconcave shape = like donut with solid center  Live for 120 days; recycled by liver/spleen  Hemoglobin = part that attaches to oxygen and carbon dioxide

White Blood Cells  Function: defend against infection  Very small amount of total blood composition  1 WBC for every 700 RBC  Different types of white blood cells play different roles  Also part of the immune system: able to pass into lymphatic system and attack pathogens

Platelets  Function: form clots to control bleeding  Made in bone marrow  Very small amount of total blood composition  Form complex net to seal wound and begin repair process  Disorders include forming large clots (in arteries) and the inability to clot (hemophilia)

Plasma  Function: transports fluids and molecules throughout the body  55% of total blood composition  Mostly water: also glucose, vitamins, minerals, proteins, electrolytes, hormones and wastes

Is blood ever blue?  No  It’s always varying shades of red  The iron in hemoglobin on red blood cells give it the red color Becomes bright red when it absorbs oxygen Publishers use blue color to distinguish blood with low oxygen from blood with high oxygen

Explaining Blood Flow of Heart Right Side of the Heart  Deoxygenated Blood from the body flows into the Right Atrium of the heart then gets pumped from the Right Ventricle to the Lungs Left Side of the Heart  Oxygenated Blood flows from the lungs into the Left Atrium of the heart then gets pumped from the Left Ventricle through the Aorta to your Body