Breathing and Transport of Gases HOMEOSTASIS: THE CARDIOPULMONARY SYSTEM Breathing and Transport of Gases

Homeostasis Exchange of O2 and CO2 Need O2 for producing energy RBC transport O2 Heart pumps blood

Transport of Blood

The Pump (Heart) 4 chambers Double pump Beats 60-100 times a minute Regulated by nervous system Epinephrine speeds up heart rate Controlled by pacemaker Receives electrical signal from medulla Triggers contraction of heart muscles in two waves (systolic & diastolic)

Septum

Flow of Blood Oxygen poor blood from body enters upper right atrium Atrium contracts Blood flows thru tricuspid valve to right ventricle Blood is pumped out through pulmonary arteries to lungs Blood picks up oxygen and returns via pulmonary veins Blood enters left atrium Blood flows through bicuspid valve into left ventricle Ventricle contracts Blood is pumped out through the aorta

Heart Valves Prevent backflow Malfunctions Heart murmur = valve doesn’t stop backflow Atherosclerosis Many others!

Malfunctions Atherosclerosis: buildup of plaque High blood pressure Stroke Heart Attack

Exchange of Gases

Inhalation Air is drawn into the lungs when….. Diaphragm moves down (contracted) Creates more space in lungs Less air pressure Air rushes in “Negative Pressure”

Exhalation Air is pushed out of lungs when Diaphragm moves up (relaxed) Creates less space in the lungs More air pressure Air is forced out

Breathing Rate Controlled by pH level of the blood Less O2, lower pH (acid), Rate of inhalation speeds up Medulla regulates rate

Exchange of Gases Cellular Level

Exchange of Gases Occurs in the Alveoli (small air sacs in lungs) Smaller to increase surface area Surrounded by capillaries (small blood vessels) Oxygen and carbon dioxide are exchanged through diffusion Red Blood Cells (RBC) bind to oxygen with the help of hemoglobin (protein inside RBCs that carry oxygen)

Transport of Gases Oxygen carried by RBC in blood Blood is contained in three types of vessels: 1. Artery Carries blood away from heart to body Thick walls to withstand pressure

2. Vein Carry blood back to heart Thinner walls Use valves to prevent backflow Skeletal muscles help push blood up

3. Capillary Smallest blood vessel One cell thick Exchanges materials through diffusion

Connecting Systems

Fluid Connective Tissue = Blood

Different body systems function to keep blood composition and chemistry within normal limits (WNL)

Functions Transports nutrients Destroy microorganisms Maintain water balance Regulate body temperature Carry platelets (tiny blood cells that help form clots to stop bleeding)

2 Components of the Blood Plasma Formed Elements (RBC, WBC, and platelets)

A. Red Blood Cells Small and biconcave to increase surface area No nucleus to conserve space Contains hemoglobin (protein) to bind and transport O2 Erythropoietin in kidneys stimulates production of RBC by bone marrow

B. White Blood Cells Large No hemoglobin Nucleus Fight infections Phagocytes activate T cells Pathogens activate B cells to produce antibodies

C. Platelets: Clotting If a blood vessel is punctured…. Step 1: Platelets congregate and form a “plug”

Clotting Step 2: Fibrin Threads form and trap RBC (like a spiderweb)

Antigen on Surface of RBC Opposite antibody in Plasma Blood Types – 4 Types Blood Type Antigen on Surface of RBC Opposite antibody in Plasma A Anti-B B Anti-A AB A, B None O Anti-A and Anti-B

Blood Transfusions Type B recipient can receive Type A blood through agglutination

Transport by blood - hormones Hormone = Chemical signal Secreted by Endocrine Glands Bind to specific receptors on target cell

Endocrine Glands