Circulatory & Respiratory Systems Chapter 33

Materials Are Transported and Heat is Distributed in the Body  Your body must  transport nutrients  transport hormones  transport gases  get rid of wastes  The circulatory and respiratory systems must work together to accomplish these needs.  The circulatory system transports materials and the respiratory system exchanges gases.

Circulatory System  Connects the muscles and organs of the body through a network of vessels  Transports blood  A mixture of specialized cells and fluids  Heart, muscle that pumps blood through the body

Different Kinds of Molecules That Move Through the Circulatory System  1. Nutrients:  Digested food  2. Oxygen:  From the lungs then to all the body cells  3. Metabolic wastes :  Carbon dioxide  4. Hormones:  Help coordinate many bodily activities  5. Heat:  Distributes heat fairly uniformly

Blood Circulates Through a Network of Vessels  Artery:  Vessel that carries blood away from the heart  Arteries have 3 layers:  1. innermost layer - endothelium, thin, single layer  2. middle layer - smooth, muscular, elastic  3. outer layer - protective layer connective tissue  Capillaries:  Connective vessels that allow the exchange (diffusion) of gases, nutrients, hormones and other molecules  Vein:  Vessel that carries blood back to the heart

Leaked fluids  Lymphatic system:  A system of the body that collects and recycles fluids that leak from the circulatory system  Involved in fighting infections  Made up of a network of vessels called the lymphatic vessels and tiny bean-shaped structures called lymph nodes  Thymus, tonsils, spleen, bone marrow.

Red Blood Cells  Red Blood Cells (Erthrocytes)  most cells that make up blood are red blood cells  carry oxygen  Hemoglobin:  Iron-containing proteins that bind to oxygen  Do not have a nucleus  Live about 120 days  Anemia:  A condition in which the oxygen-carrying ability of the blood is reduced

White Blood Cells  White Blood Cells (Leukocytes)  Are out numbered by RBC's 1/500  Primary function is to defend the body against disease  Larger than RBC’s  Have a nucleus  Live months to years

Platelets  Cell fragments  Important in blood clotting  Contain fibrin:  Clotting enzyme that forms scabs

Blood Types  Four major blood types  A, B, AB and O  Protein markers on surface of the RBC's  AB - universal receiver  O - universal donor  Rh Factor:  Antigen on the surface of the RBC’s  If you have it, you are Rh+  If you don't, you are Rh-

The Heart  Blood vessels allow for movement of blood to all cells.  The pumping action is needed to provide pressure to move the blood throughout the body.  Two separate circulatory loops  Right side - driving the pulmonary circulation loop, pumps oxygen-poor blood through the pulmonary arteries to the lungs  Left side - driving the systemic circulation loop, pumps oxygen-rich blood through the arteries to the entire body

Blood Follows a Specific Path  Septum:  Tissue that divides the heart into left and right halves  Atria (atrium):  Receiving chambers  Ventricle (ventricles):  Thick-walled sending chambers

The Path Blood Follows Through The Body  1. Oxygen-poor blood returns to the heart through the inferior and superior vena cava, these empty into the right atrium  2. The blood passes through a valve into the right ventricle  3. The blood is then sent out of the heart through the pulmonary artery to the lungs.  4. In the capillaries of the lungs gas exchange occurs then returns to the heart through the pulmonary vein. The blood is now oxygen-rich.  5. The blood enters the left atrium passes through a valve into the left ventricle.  6. The blood is then sent out of the heart through, the largest artery in the body, aorta.  7. The blood travels to all the cells in the body where it drops off oxygen and nutrients, and picks up carbon dioxide and wastes.  8. The cycle starts all over again through the vena cava.

Heart Contraction  Sinoatrial node:  Small cluster of cardiac muscle cells that act as a pacemaker, located in the upper wall of the right atrium  Heart contractions occur at a rate of 72 times per minute, more or less depending on your level of physical activity.  Blood pressure:  The force exerted by the blood as it moves through the vessels  Systolic:  Tells how much pressure is exerted when the heart contracts and blood flows through the arteries  Diastolic:  Tells how much pressure is exerted when the heart relaxes  Hypertension:  High blood pressure, places strain on the walls of the arteries and increases the chances that a vessel will burst  Electrocardiogram (ECG or EKG):  Another way to monitor the heart's function, electrical impulses

Heart Rate  Pulse:  A series of pressure waves within an artery caused by the contraction of the left ventricle  Examples:  Heart attack occurs when an area of the heart muscle dies and stops working  Stroke occurs when an area of the brain tissue dies

The Respiratory System  Gases Must Be Exchanged  Oxygen is used by your cells to completely oxidize glucose and then make ATP  The main energy currency for your cells.  The gases that enter your body must be transported by the circulatory system and then exchanged at the cells.  Diaphragm:  Powerful muscle in the bottom of the rib cage that aids in respiration

The Path Air Follows  1. Air enters the respiratory system through the nose (or mouth)  2. Air passes through a muscular tube in the upper throat  Pharynx:  Tube for food and air  3. Air continues through the larynx  Voice box  4. The epiglottis is a flap of tissue that closes off the trachea  5. Air passes into the trachea  long straight tube in the chest cavity (windpipe)  6. Dividing into smaller tubes called the bronchi  Lead to the lungs  7. Bronchioles:  Smaller tubes in the lungs  8. Aveoli:  Cluster of air sacs in the lungs that increase the surface area - when gases are exchanged

Oxygen and Carbon Dioxide Are Transported in the Blood  1. Oxygen from the air reaches the lungs  2. Oxygen diffuses from the alveoli into the capillaries - hemoglobin carries the oxygen  3. Oxygen-rich blood travels to the heart (left atrium), then to the body (aorta)  4. Oxygen diffuses into the cells  5. Carbon dioxide diffuses from the cells into the blood  6. Oxygen-poor blood is pumped to the heart (right atrium), then to the lungs  7. In the lungs, carbon dioxide/oxygen is exchanged in the alveoli  8. The carbon dioxide is then exhaled

Respiratory Diseases  Asthma:  Disease in which the bronchioles of the lungs constrict because of their sensitivity to certain stimuli air  Emphysema:  Disease in which the lungs' alveoli lose the elasticity, making it difficult to release carbon dioxide during exhalation  Constant fatigue and breathlessness  Lung cancer  Disease characterized by abnormal cell growth