Comparative Vertebrate Physiology Blood and hemodynamics.
-
Upload
bernadette-wiggins -
Category
Documents
-
view
226 -
download
4
Transcript of Comparative Vertebrate Physiology Blood and hemodynamics.
Comparative Vertebrate Physiology
Blood and hemodynamics
Blood composition Plasma and formed elements Formed elements
Erythrocytes, leukocytes, platelets Hematocrit
<45% anemia (O2 delivery problems) >45% polycythemia (circulation problem)
Plasma
WBC’s, platelets
RBC’s
Plasma Contents
90% water Protein (albumin) Fats, amino acids, salts, gases, enzymes,
hormones Narrow osmolality range in mammals only
Erythrocytes Most verts. have a nucleus (exceptions some fish, amphibians, humans) Shape (oval in Aves,spherical, elliptical to biconcave disc in mammals)
Leukocytes Protection against invasion Granulocytes
Neutrophils, eosinophils, basophils
• Agranulocytes• No cytoplasmic granules• Lymphocytes, monocytes
Platelets Fragments of bone marrow
(megakaryocytes) Clotting function Age quickly (enucleate)
Erythropoiesis1. Ribosome manufacturing
2. Hb synthesis and accumulation
3. Nucleus and organelle ejection
Erythropoiesis
Rheology Relationship between pressure and flow
of fluid 1. Viscosity
Rheology Flow rate = 1/viscosity
Rheology Flow rate is directly proportional to
differences in pressure
Rheology Flow rate is indirectly proportional to
vessel length
Rheology Flow rate is directly proportional to the
fourth power of the radius of the vessel
Hemodynamics Rate of blood flow slowest in highest cross sectional
areas Functional significance
Blood flow Laminar flow
Continuous (small vessels) Pulsatile (large vessels)
Blood flow Turbulent flow
Definition (obstruction, sharp turns, high flow rate)
Occurs after aortic and pulmonary valves
Blood flow
Reynold’s number determines whether flow is laminar or turbulent
Re Directly proportional to velocity Directly proportional to the radius Inversely proportional to viscosity
Blood flow