Lab 12: Circulatory System Flashcards
The circulatory system consists of
blood + blood vessels + heat
Blood travels within five main types of vessels
arteries, arterioles, capillaries, venules and veins (vary in diameter, length, and wall structure.)
cardiovascular system
heart + blood vessels.
BLOOD
- cell type
- function
• specialized connective tissue (contains cells and cell fragments, ground substance (plasma) and dissolved protein fibers)
Function
• transport media (oxygen, carbon dioxide, nutrients, hormones and wastes)
• maintain homeostasis (regulating pH, adjusting body temperature and maintaining osmotic pressure of cells)
• can clot (prevent excessive loss)
Blood average volume
- 5-6 L in adult males
- 4-5 L in adult females.
Blood has two components:
(1) formed elements – cells and cell fragments
• the red blood cells (erythrocytes)
• white blood cells (leukocytes)
• platelets
(2) plasma
the red blood cells (erythrocytes)
- most numerous (outnumber WBC 700:1)
- non-nucleated biconcave discs
- contain hemoglobin: oxygen-carrying pigment
white blood cells (leukocytes)
Granulocytes: contains granules
- Neutrophil
- Eosinophil
- Basophil
Agranulocytes: no granules
- Lymphocyte
- Monocyte
Neutrophils
- multilobed
- 10-12 μm in diameter
- 60 - 70%
- Function: phagocytic (destroy pathogenic micro-organisms/ foreign matter)
Eosinophils
- bilobed
- 10-12 μm in diameter
- 2 - 4%
- Function: control local responses allergic reactions. defense against parasites.
Basophils
- S-shaped nucleus
- 8-10 μm in diameter
- 0.5 - 1%
- Function: involved in allergic reactions, releasing heparin and histamine that enhance the inflammatory response.
Lymphocytes
- large nucleus (takes up whole thing)
- small =6-9 μm; large =10-14 μm
- 20 - 25% of the leukocyte population
- Function: produce antibodies and other agents involved in the immune process.
Monocytes
- horseshoe nucleus
- 12-20 μm in diameter.
- 3 - 8%
- Function: highly phagocytic
Platelets
- 150,000 to 400,000 per cubic millimeter of blood (1 mm3 = 1 μL = 10-6 liter).
- Disc-shaped
- 2-4 μm in diameter
- contain many granules
- no nucleus
- Function: help stop blood loss from damaged vessels by forming a platelet plug and also help promote blood clotting.
Test: complete blood cell count
gives a profile of the number of red blood cells, white blood cells, and platelets per cubic mm of blood (mm3);
Blood analysis: Performing a Differential White Blood Cell Count
- Purpose: determine the percentage of each of the five types of leukocytes in a sample of blood
- Function: deviation from the normal percentages of white blood cells may indicate a certain disease condition
- RESULTS:
- High neutrophil: bacterial infections or poisons, while a low percentage may be caused by a toxic reaction to certain drugs.
- High eosinophil: may be due to presence of an allergy or parasitic infection
- High lymphocyte: infectious mononucleosis, measles, mumps, and tuberculosis
- High monocytes: tuberculosis, a protozoan infection, Hodgkin’s disease or infectious mononucleosis.
Blood analysis: Hematocrit
• The percentage of total blood volume occupied by RBCs is called the hematocrit and this value is about 45%
- Males 40 - 54%
- Females it is 38 - 46%.
Blood analysis: Hemoglobin Measurement
-2 test types
- concentration of hemoglobin indicator of the oxygen-carrying capacity of the blood
- 13.5 - 18 g/100 ml of blood for males
- 12 - 16 g/100 ml of blood for females.
Measured: Tallquist Scale or Hemoglobinometer
Blood analysis: Erythrocyte (Red Blood Cell) Count
- low RBC count: Anemia
- high RBC count: Polycythemia
- Males: 4.5 – 6.5 million per cubic millimeter of blood
- Females: 3.9 - 5.6 million/mm3 of blood
Blood analysis: Leukocyte (White Blood Cell) Count
- high WBC: bacterial infections, appendicitis, leukemia, pregnancy, ulcers and in many other conditions
- low WBC: measles, infectious hepatitis, and cirrhosis of the liver, in persons who are receiving radiation or antibiotic therapy
- Healthy: 5,000 and 10,000 WBC per cubic millimeter of blood
- leukocytosis: WBC count more than 10,000
- leukopenia: WBC count less than 5,000
Blood analysis: Clotting Time
• Blood normally clots within 2 to 6 minutes.
Anemia
- decreased amount of hemoglobin in the bloo so decreased amount of oxygen will reach tissues.
- result from a decreased production of erythrocytes if deficiencies in iron or Vitamin B12 occurred or if certain types of malignancies were present.
Rh Factor
Rh factor
• a system including 12 surface antigens. (antigen D is the most antigenic)
• Rh positive (Rh+) = presence of antigen D
• no natural antibodies are present in the plasma
• Rh negative (Rh-) will form antibodies
Blood Transfusions
- unsuccessful transfusion = RBC agglutination (clumping)
- Clumping destroyed by immune system, leading to hemolysis, possible kidney failure or death.
- blood donations stored as RBC, without plasma (therefore free of antibodies)
- RBCs Donation: when low oxygen-carrying capacity
- Plasma Donation: when low blood volume
_____ conduct blood away from the heart and _____conduct blood towards the heart. Interconnecting the two major blood vessel types are ______
ARTERIES conduct blood away from the heart and VEINS conduct blood towards the heart. Interconnecting the two major blood vessel types are microscopic CAPILIARIES
Capiliaries
- Interconnecting artiers and veins
- single layer of endothelial cells (simple squamous cells) + basement membrane
- Function: exchange of materials between the circulatory system and the tissues only occurs through the thin walled capillaries.
Arteries
- overview
- distinguishing features
- thick-walled
- many elastic fibres + smooth muscle cells
- conduct blood away from the heart
- must be able to withstand the pressure of the blood as it is forced through the vessels by the pumping heart
- able to recoil after the original distension in order to transmit pressure for the maintenance of blood flow
Distinguishing Features:
• smaller lumen
• thicker wall
• round artery shape (result of the large number of elastic fibers and smooth muscle cells in the wall of the artery)
Veins
- overview
- distinguishing features
- thin walls
- few smooth muscle cells + few elastic fibres
- conduct blood back toward the heart
- sometimes functioning against the force of gravity.
- Valves: adaptation for the prevention of the back flow of blood, located at regular intervals within most veins
Distinguishing Features:
• larger lumen
• thinner wall
• irregular shape and may be collapsed on the slide
Artery: Structural Layers
Tunica interna (intima) - elastica interna
Tunica media
Tunica externa (adventitia) - elastica externa
Atria v. Ventricles
Atria - thin-walled receiving chambers for blood returning to the heart from veins
Ventricles - pumping chambers with thick muscular wall.
What delivers blood to the heart
- R/L. Coronary Arteries: base of the aorta to deliver 02 blood to capillaries over the heart surface
- Coronary Veins: drain blood from capillaries –>coronary sinus
Superior Vena Cava
delivers venous blood collected from:
- head, neck and arm regions –> right atrium.
The human heart has three major branches off the aorta
- the brachiocephalic artery
- left common carotid artery
- left subclavian artery
Inferior Vena Cava
delivers venous blood collected from:
- lower body regions –> right atrium.
Blood Flow through the heart
superior vena cava/inferior vena cava/coronary sinus –> –> right atrium –> [tricuspid valve] –> right ventricle –> [pulmonary semilunar valve] –> pulmonary trunk –> right/left pulmonary artery –> lungs –> R/L pulmonary veins –> left atrium –> [bicuspid valve] –> left ventricle –> [aortic semilunar valve] –> ascending aorta –> aortic arch–> rest of body
coronary sinus
returns blood from myocardium
2 major circulatory pathways
pulmonary circulation + systemic circulation.
pulmonary circulation
- arteries/veins transport blood: heart –> lungs –> heart
- Start: R. Ventricle
- End: L. Atrium
systemic circulation
- transports O2 blood to all body, returns deoxygenated blood to heart
- Start: L. Ventricle
- End: R. Atrium
Fetal
blood carries on gas exchange in the placenta (since no air in lungs)
foramen ovale
- shunts blood from r. atrium to L. atrium
* Avoid lungs
Placenta
- Both fetal and maternal tissue
- Large blood sinus that contain maternal blood
- Umbilical cord = 2 umbilical arteries + 1 umbilical vein
- The umbilical arteries meet the umbilical vein at the umbilicus (navel or belly button)
- Umbilical vein is going from gas exchange to fetus (high oxygen) Only the umbilical vein contains oxygenated blood
- Umbilical arteries is going from baby to placenta (low o2) branches of the internal iliac arteries
- At birth, the umbilical vein, the umbilical arteries, the ductus venosus, the foramen ovale and the ductus arteriosus all close off permanently.
ductus venosus
bypass liver
• hepatic portal vein (liver) –>inferior vena cava
• ductus venosus (bypass liver)–> inferior vena cava
ductus Arteriorus
Avoid the Lungs
•right atrium (mix with superior vena cava)
-foramen ovale –> L. atrium
- pulmonary trunk. –> ductus arteriosus –> aorta
