the circulatory system n.
Skip this Video
Loading SlideShow in 5 Seconds..
The Circulatory System PowerPoint Presentation
Download Presentation
The Circulatory System

The Circulatory System

1474 Vues Download Presentation
Télécharger la présentation

The Circulatory System

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. The Circulatory System

  2. Need stethoscopes and straws/plastecine

  3. Activity 1 • lay your hand (palm side up) on their desk and • count how many times you can open and close their hand for one minute. • Ready….set….go! • Timer

  4. Activity 2 Discussion: • Over 170 years ago, a man named Laennec invented the first stethoscope. It was a wooden tube about 1 inch in diameter and about 10 inches long. Materials: • stethescopes Procedure: • pair up and listen to your partner's heartbeat by placing the tube over the partner's heart. • Count the number of beats per 30 seconds. Add this number together twice to find out how many times each minute the person's heart beats.

  5. Parts of the Circulatory System Blood vessels Blood Heart Lets take a closer look…

  6. 1. Blood Vessels Blood vessel = a tube for carrying blood • These tubes are how the heart pumps the blood all over the body. We call this CIRCULATION Blood moves through 3 kinds of blood vessels: • Arteries • Capillaries • Veins

  7. a) Arteries Carry blood AWAY from the heart TO the body or lungs Common misconception… The largest artery = the aorta This is the main branch off the heart, off which blood flows to everywhere except to the lungs Stenosis of the aorta = … Small arteries are called arterioles

  8. b) Capillaries As blood vessels branch smaller andsmaller, they eventually become only one cell thick = capillaries This is how every cell in our body gets blood Capillaries are the ONLY site of molecular exchange!!! Gas, nutrients, water, nitrogenous, wastes, hormones, etc.

  9. Movement of blood – 2. Capillaries Capillaries Nutrients cell Oxygen Wastes Carbon dioxide

  10. c) Veins • Carry blood back TO the heart FROM the body or lungs • Common misconception… • The biggest vein is the vena cava • Small veins are called venules

  11. Which way is the blood flowing?

  12. Flow of blood through blood vessels in the body Aorta Arteries Arterioles Heart Capillaries (exchange) Venules Veins Vena cava Heart

  13. Comparison of Veins & Arteries

  14. Discuss accidental amputations – people fainting • • • Nova article on Stapp -

  15. Arteries Have a pulse Transport blood away from the heart; Carry Oxygenated Blood (except the Pulmonary Artery); Have relatively narrow lumens (see diagram); Have more muscle / elastic tissue; Transports blood under high pressure; Do not have valves (except for the semi-lunar valves of the pulmonary artery and the aorta). Veins Do not have a pulse Transport blood towards the heart;  Carry De-oxygenated Blood (except the Pulmonary Vein);  Have relatively wide lumens (see diagram); Have less muscle / elastic tissue; Transports blood under low pressure;  Have valves to prevent blood flowing in the wrong direction Comparison of Veins & Arteries

  16. Varicose veins • • • See handout • Squeezing vein

  17. Parts of the Circulatory System Blood vessels Blood Heart Lets take a closer look…

  18. 2. Blood • Average adult 4-6 liters of blood

  19. 2. Blood 1. Plasma • Clear/straw colored liquid portion of blood • Can look cloudy after a fatty meal, gross!!! • Components of plasma: • water, dissolved gases, proteins, hormones, electrolytes, sugar, vitamins, and waste products • 55% of blood volume • Function - Transport CO2, nutrients from gut, hormones, and distributes heat

  20. 2.Red Blood Cells (RBCs) • Aka erythrocytes • 45% of blood volume • primary function: carry O2 lungs  body • DO NOT have a nucleus • Contain iron and hemoglobin • That’s why they’re red in color. • Hemoglobin is the substance to which O2 molecules bind for transport through the bloodstream. • 30 trillion RBCs • life span = 120 days • about 2 million die & are replaced every second • worn out RBC’s are filtered out by the liver and spleen

  21. 3. White blood cells (WBCs) • Aka leukocytes • <1% of blood volume • are a part of the immune system and help our bodies fight infection • HAVE a nucleus • Circulate in the blood so that they can be transported to an area where an infection has developed. • If WBC # es = a sign of an infection somewhere in body. • •

  22. 3. White blood cell’s continued… • 2 main types of WBCs:

  23. 4. Platelets • Aka thrombocytes • <1% of blood volume • Platelets are sticky, irregularly-shaped cell fragments (NOT CELLS) How a clot is formed (the good kind): • Platelets detect air/injury and become sticky  also begin to break apart  these react with stuff in plasma to make thromboplastin Thromboplastin + prothrombin (+ Ca+ & Vit K) = Thrombin  Thrombin + Fibrinogen => Fibrin (tiny threads)  fibrin threads form a web-like mesh traps the blood cells within it This hardens as it dries, forming a clot, or "scab/bruise“ • What do you think happens if Calcium and vitamin Kare low/missing? • •

  24. Blood clotting process (Steps) • blood vessel injured Platelets detect Air Ruptured platelets Thromboplastinogen Thromboplastin (active) (inactive) (Ca, vit K) Prothrombin Thrombin (active) (inactive) Fibrinogen Fibrin (active) (inactive)

  25. What is the role of blood? TO HELP MAINTAIN HOMEOSTASIS by: • Transport • O2, CO2, food, nitrogenous wastes, hormones, etc • Protection – through immune system • Guards against microbial invasion (immune system) • Circulate clotting factors to prevent blood loss in case of injury • Regulation • controls levels of hormones, enzymes, temperature, pH

  26. Blood Groups Antigens: • these are proteins that are presented on the surface of cells (even ours) and act as a name tag • They identify self vs. non-self • Are able to trigger the production of antibodies Antibodies • Proteins used by the immune system to identify invaders to our body which begins an immune response (an attack) to destroy the invader

  27. Blood Types humans fall into 4 basic groups, based on which ANTIGEN(s) are present on their RBCs Type A - 41% Type B - 10% Type O - 45% Type AB - 4% The Rh (Rhesus) factor is the 2nd grouping system based on if the Rh ANTIGEN is present / absent: 85% Rh+ 15% Rh –

  28. ABO Blood Groups Blood TypeAntigen on RBC’sAntibodies in Plasma A A Anti – B B B Anti – A AB AB None O None Anti A & B Rh+ Rh none Rh- none Anti - Rh • Remember, antibodies are there to help destroy foreign (non-self) cells which are flagged by antigens • Why is this IMPORTANT ? • This chart indicates that people must know their blood types for safe transfusions because we are born with antibodies in our blood that will attack antigens of other blood groups.

  29. Transfusion Chart Donating A → A, AB B → B, AB AB → AB O → O, A, B, AB RH+ → RH+ RH- → RH+, RH- Universal donor = O RH- Universal receiver = AB RH+ Receiving A ← A, O B ← B, O AB ← AB, A, B, O O ← O RH+ ← RH+, RH- RH- ← RH-

  30. Rule of thumb: Whatever blood type you are, your body ‘hates’ all the rest

  31. Blood Transfusions • if blood is mixed and it is foreign to the recipient it will cause an immune response and clumping will occur → Agglutination

  32. Blood Transfusions • in emergency transfusions, O RH-, or even plasma is used (missing RBC’s & antigens) so blood types do not have to match *A simple blood test is used to determine the Rh factor of an individual.

  33. Just blood Add A Add B Add AB antibodies antibodies antibodies

  34. Pregnancy & antibodies Problem when the mother is Rh- and baby is Rh+ (from father) Does not affect 1st child, but mother begins to produce antibodies These antibodies stay in her body and if 2nd child is also Rh+ then complications can arise In this case mother is given an injection (Rhogam) to neutralize her antibodies (2nd child will be safe) These injections continue for each child that has opposite Rh factors from mother Rhogam binds to, and lead to the destruction of, fetal Rh+ rbcs that have passed from the fetal circulation to the maternal circulation. Prevents mom from producing permanent antibodies

  35. RH factor and Pregnancy

  36. Blood Genotyping • Genotype = the genetic makeup of an individual • Punnett Square = a diagram that is used to predict an outcome of a particular cross or breeding experiment • Ex: Mother blood type A  Father blood type AB Mom has 2 options for her genotype Mom Mom A o A A Ao A AA AA A AA Dad Dad B AB Bo B AB AB

  37. Mom A O • More examples Child is either type AB, A, B, or O BO B AB Dad O AO OO Mom B O What are the parent’s genotypes? BO B BB Dad O BO OO

  38. Announcements • Lab reports are OVERDUE • Quiz on Monday – it will be difficult • Blood vessels • Blood components (rbc, wbc, plasma, platelets) • Blood clotting • Blood compatibilities •

  39. Parts of the Circulatory System Blood vessels Blood Heart Lets take a closer look…

  40. A Closer Look at the Heart Cool facts • The heart begins beating at four weeks after conception and does not stop until death • ~ size of fist • 72 beats/pumps 5 liters – every minute • A kitchen faucet would need to be turned on all the way for at least 45 years to equal the amount of blood pumped by the heart in an average lifetime • The heart pumps oxygenated blood through the aorta (the largest artery) at about 1 mile (1.6 km) per hour. By the time blood reaches the capillaries, it is moving at around 43 inches (109 cm) per hour. • Blood is actually a tissue. When the body is at rest, it takes only six seconds for the blood to go from the heart to the lungs and back, only eight seconds for it to go the brain and back, and only 16 seconds for it to reach the toes and travel all the way back to the heart • Grab a tennis ball and squeeze it tightly: that’s how hard the beating heart works to pump blood

  41. 3. Heart 1 3 4 2 Heart structure: • 1 heart = 2 side by side pumps • Each side has 2 chambers (= 4 chambers in total)

  42. 3. Heart Atrium = chamber that receives blood from the body / lungs Ventricle = chamber that pushes blood out of the heart to the lungs / body Have VERY strong muscles Heart valves – flaps in the heart that open to allow blood to flow in only 1 direction Will close to stop blood from back-flowing

  43. External Anatomy of the Heart

  44. Internal Anatomy of the Heart

  45. Superior Vena cava Ascending Aorta Right Pulm.Artery Left Pulm. Artery Right atrium Pulmonary trunk Right Pulm. Veins Left Pulm. Veins Right Semilunar valve Left Atrium Left AV Valve Right AV valve Left semilunar valve Right Ventricle Left ventricle Septum Inferior Vena cava Descending Aorta *AV = atrioventricular

  46. Blood Flow Through the Heart

  47. • • •

  48. The “Cardiac Cycle” Circulation of Blood • Circulation is divided into 2 major pathways: • Pulmonary circulation (heart ↔ lungs) • Systemic circulation (heart ↔ all body cells)