Unit 9 Circulatory System Blood CIRCULATORY SYSTEM Heart

Unit 9 Circulatory System: Blood

CIRCULATORY SYSTEM • Heart • Veins • Capillaries • Arteries • lymph vessels • lymph glands

Functions of the circulatory system: Transport and exchange oxygen, nutrients and carbon dioxide Remove waste materials Prevent infection Regulate body temperature.

Anatomy and Physiology of the Blood is an important component of the circulatory system. Anatomically and functionally, blood is a connective tissue.

Components of Blood 55% - Plasma: a yellow liquid component of blood 1. water (90%) 2. solids (10%) - proteins, glucose, clotting factors, mineral ions, hormones, and carbon dioxide (waste)

Components of Blood 45% - Cellular Component • Erythrocytes (RBC) • contain hemoglobin, • red color • carry oxygen • Leukocytes (WBC) • help the body fight bacteria and infection • formed in the small ends of bones • Leukocyte # increases when a tissue is damaged or has an infection • Thrombocytes (platelets) • Aid the formation of blood clots by releasing various protein substances • contains fibrin - allows blood to clot (coagulate)

Erythrocytes (RBC) Thrombocytes (platelets) Leukocytes (WBC)

ABO Blood Types • Classified based on certain antigens and antibodies found on surface of red blood cells • Agglutination • RBC coagulate • Occurs when two different blood types combine Parent Alleles A B O AA (A) AB (AB) AO (A) AB (AB) BB (B) BO (B) AO (A) BO (B) OO (O) ABO Blood Type Antigen A Antigen B Antibo dy anti-A Antibody Anti-B A yes no no yes B no yes no O no no yes AB yes no no

Human ABO Blood Types Image courtesy of Wikipedia.

Rh Factor • Does not affect your health except during pregnancy • A woman is at risk when she is Rh- and her partner Rh+ • This combination can produce a child who is Rh+ • mother to creates antibodies against the Rh factor, thus treating an Rh+ baby like an intruder in her body. If this happens the mother is said to be sensitized. • Rh antibodies will then attack an Rh+ baby's blood, causing it to breaking down the red blood cells of the baby and anemia will develop. • In severe cases this hemolytic disease can cause illness, brain damage and even death. • Rh immunoglobulin (Rh. Ig) is a blood product given via injection to help the Rhmother by suppressing her ability to react to the Rh+ red cells

Rh Factor Rh+ Rh- RBC Type Antibodies present None Anti-Rh Antigens present Rh antigen None

Parts of the Circulatory System • Pulmonary circulation - takes the blood from the heart to the lungs, where it is oxygenated, and returns it to the heart. Parts involved: heart, pulmonary arteries, capillaries of the lungs, and pulmonary veins. • Systemic circulation - flow of oxygenated blood from the heart to the tissues in all parts of the body and the return of un -oxygenated blood back to the heart. Parts involved: arteries, capillaries, and veins

Three types of blood vessels Photo from U. S. Federal Government courtesy of Wikipedia. → arteries → arterioles → capillaries → venules → veins →

Three types of blood vessels: Arteries • Arteries - carry blood, rich in oxygen, from the heart to other parts of the body. (Arteries = Away) -Three tissue layers thick: allow to withstand blood pressure -Highly elastic (allows dilation and constriction) - Aorta: largest artery -Divide into arterioles -Where pulse is found Note: All arteries carry oxygenated blood except for the pulmonary artery that carries deoxygenated blood to the lungs.

Pulse • only felt in arteries • spurt of high pressure blood passing along the arteries when the left ventricle contracts • elastic walls of arteries stretch • When the pulse has passed, the walls contract and this helps push the blood along. • easily felt at certain places where an artery passes near the surface of the body (pulse/pressure points) • strongest near the heart and becomes weaker as it travels away from the heart • No pulse in capillaries or veins • Pulse Rate / Heartbeat /Heart rate -Measured in bpm (beats per minute) -Average Resting Adult: 60 -80 bpm -Tachycardia – exceeds normal range -Bradycardia – below normal range -Men: 68 -75 bpm -Women: 72 -80 bpm -Athletes: 40 -60 bpm • Factors increase heart rate -dehydration -weight -exercise -smoking -caffeine

Blood Pressure • Pressure of blood against the walls of the main arteries • Pressure highest when left ventricle contracts, forcing blood into atrium • Systole – contraction of left ventricle • Pressure lowest between pulses, during relaxtion (ventricles refill) • Diastole – relaxation of ventricle • BP = systole/diastole = 120/80 mm. Hg = normal BP Hypertension – high blood pressure Hypotension – low blood pressure Sphygmomanometer – measures blood pressure

Capillaries • connect arteries to veins; specifically arterioles to venules • Gas Exchange: distribute the nutrients and oxygen to the body's tissues and remove deoxygenated blood and wastes • Extremely thin: only one cell thick • Capillary beds are so dense that no living cell is far from its supply of oxygen and food.

Capillary Bed Interaction of molecules flowing in and out of blood at a capillary bed.

Veins • return blood to the heart from all parts of the body. • No pulse • Low pressure • Less elastic and have thinner walls than arteries • Have the same three layers as arteries • Have to overcome gravity • One-way valves – prevent backflow • Skeletal muscle contractions • carry deoxygenated blood towards the lungs where oxygen is received via the pulmonary capillaries. Note: The pulmonary vein that carries oxygenated blood from the lungs to the left atrium of the heart is an exception.

Major Arteries & Veins: Pulmonary Circulation • Pulmonary Artery and Vein – the only arteries that carry deoxygenated blood; carries it to the lung

Major Arteries & Veins: Systemic Circulation • Aorta • the main artery that pumps blood into the body • largest artery in body • Inferior/Superior Vena cava • allows blood to be returned to the heart • largest vein in body • Arteries and veins to and from many organs often run alongside each other and have the same name • Renal artery and vein – kidney • Femoral artery and vein - hind limbs (legs) • Subclavian artery and vein - forelimbs (arms) • Carotid artery - to the head • Jugular vein – from the head • Hepatic portal vein • carries blood from the intestines to the liver • only vessel that transports blood from one organ to another rather than to or from the heart like arteries or veins.

Blood Disorders • Anemia – Causes • Loss of blood due to injury • Infestations of blood-sucking parasites • Low levels of red cell production and hemoglobin • poor nutrition – Symptoms • Chest pain • Dizziness or light-headedness (especially when standing up or with exertion) • Fatigue or lack of energy • Headaches, problems concentrating • Shortness of breath (especially during exercise) – Treatment • Blood transfusions • Corticosteroids or other medicines that suppress the immune system • Erythropoietin, a medicine that helps your bone marrow make more blood cells • Supplements of iron, vitamin B 12, folic acid, or other vitamins and minerals

Sickle Cell Anemia • • Causes – an abnormal type of hemoglobin is present which distorts the shape of red blood cells, – These fragile, sickle-shaped cells deliver less oxygen to the body's tissues. They also can clog more easily in small blood vessels, and break into pieces that disrupt blood flow. – Sickle cell anemia is inherited from both parents (recessive genetic disorder) – most common in people of African and Mediterranean descent. Symptoms – usually don't occur until after age 4 months. – Almost all patients with sickle cell anemia have painful episodes (crises), which can last from hours to days. These crises can affect the bones of the back, the long bones, and the chest; severe enough for hospital stay – Delayed growth and puberty – Fatigue – Fever – Jaundice, paleness – Rapid heart rate

Normal RBC • • Sickle Cell Treatment – need ongoing treatment, even when they are not having a painful crisis – take supplements of folic acid (essential for producing red blood cells) because red blood cells are turned over so quickly. – manage and control symptoms, limit the frequency of crises. – Painful episodes are treated with pain medicines and by drinking plenty of fluids. Nonnarcotic medications may be effective, but some patients will need narcotics. – Blood transfusions are used to treat a sickle cell crisis. They may also be used on a regular basis to help prevent strokes. – Bone marrow transplants can cure sickle cell anemia. Prognosis – In the past, sickle-cell patients often died from organ failure between ages 20 and 40. Today patients can live into their 50 s or beyond. – Causes of death include organ failure and infection. Some people with the disease experience minor, brief, infrequent episodes. Others experience severe, long-term, frequent episodes with many complications.