Cardiovascular system Flashcards
what are the 3 circulatory system functions?
- Transporting substances around the body
- Controlling body temperature
- Protecting the body
4 chambers of the heart
(2) atria: top of the heart- receive blood from veins
(2) ventricles: bottom of the heart- pump blood through arteries
Septum: divides left from right heart
Valves: keep blood flowing in one direction
Bicuspid (mitral) valve
on the left (LA and LV)
Tricuspid valve
on the right (RA and RV)
_______ carry blood away from the heart
arteries
_______ carry blood to the heart
veins
Plan of circulation in the dog (O2)
- Atmosphere to alveoli-
Bulk flow: from an area of high pressure to an area of low pressure - Alveoli to blood vessel-
Diffusion: high conc. To low - Blood vessel to heart to blood vessel-
Bulk flow - Capillaries to tissues/cells
Diffusion
Pulmonary circulation
- R ventricle pumps deoxygenated blood through the pulmonary artery to the lungs
- Blood picks up O2 from the lungs and dumps CO2 into the lungs
- Oxygenated blood is returned to the left atrium thru the pulmonary vein
Systemic circulation
Oxygenated blood from the L ventricle to the body and returns deoxygenated blood back to the heart
Coronary circulation
- Coronary arteries exit the aorta and supply oxygen/blood to heart muscle (myocardium)
- Coronary veins pick up and return deoxygenated blood from myocardium
Plasma
is the liquid, cell free part of the bloo, that has been treated with anticoagulants
Serum
is the liquid part of the blood AFTER coagulation, therefore devoid of clotting factors as fibrinogen
Erythrocytes (RBC)
- Carry O2 to the cells of the body
- Each RBC is biconcave disk, without a nucleus
- large surface area to volume ratio. Allows for faster exchange of oxygen
- bend and flex when entering small capillaries
- form stacks to flow through narrow blood vessels, stacks are called rouleaux
Sickle cell anemia
from a mutation of hemoglobin amino acid sequence
Tissue starve for oxygen
Sickle cell RBCs are fragile and easily broken, can block capillaries
Hemoglobin
- Oxygen carrier in the blood
- Is protein made up of 4 chains (2 alpha & 2 beta chains)
- Each heme group can bind one oxygen molecule
- Can bind a total of 4 oxygen molecules - Serve a purpose of transporting carbon dioxide
Carbon dioxide is bound to?
bicarbonate ion
White blood cell (WBC)
Granulocytes: cells with granules
- Polymorphonuclear leukocytes (PMN) or neutrophils
- Eosinophils
- Basophils
Agranulocytes: cells without granules
- Monocytes
- Lymphocytes
- T-lymphocytes
- B-lymphocytes
Neutrophils
- Average lifespan is 6 hours
- Functions to seek out, ingest and kill bacteria
- 50-70%
Basophils
- Similar to mast cells, contain histamine and heparin (anticoagulant)
- Involved in allergic reactions, including hypersensitivity reactions
- 0.5% -1% of circulating white blood cells
Eosinophils
- Attacks parasites; tend to line respiratory and intestinal tracts
- Circulating half-life of 18 hours and a tissue lifespan of at least 6 days
- Less than 7% of the circulating white blood cells
Monocytes
- Leave the circulatory system and become tissue macrophages
- 3 months
- Activated by T-lymphocytes; migrate in response to chemotactic stimuli to sights of inflammation to engulf and destroy bacteria
Lymphocytes
2 kinds:
- T cells (thymus derived) responsible for cellular immunity
- B cells (bone marrow/bursal-derived) responsible for humoral immunity
Platelets
- Called thrombocytes
- Function is to stop bleeding by clotting and clumping blood vessel injuries (homeostasis)
- Have no nucleus, fragments of cytoplasm, derived from megakaryocytes of the bone marrow, and then enter circulation
- Found ONLY in mammals, where as other animals (birds, amphibians) thrombocytes circulate as intact mononuclear cells
Origin and differentiation of blood cells
- Erythropoietin, interleukins, and several colony stimulating factors stimulate conversion of hematopoietic stem cell to committed blood progenitor cells
- Bone marrow lymphocyte precursors from B and T lymphocyte cells
The process of erythropoiesis
a.Takes place in the spleen
b.Requires vitamin B12 and folate
c.Is inhibited by erythropoietin
d.Is stimulated when oxygen decreases in the blood
e. Both b and d
both b and d
Old, da,eged, or defective erythrocytes are removed from the blood by
Eosinophils
Lymphocytes
Macrophages
Monocytes
macrophages
One molecule of hemoglobin carries
One oxygen molecule
Four oxygen molecule
Lymphocytes
Four oxygen molecule
