Blood & Heart Anatomy PDF

CIRCULATORY SYSTEM Tamethia Perkins MS, RRT-NPS, RRT-ACCS RT 3005/6005 BLOOD Cells – Erythrocytes – Leukocytes – Thrombocytes Plasma RBCs  Biconcave discs (7.5 diameter and 2.5 thickness). Contains the Hgb for O2 transport.  Produced in the bone marrow at a rate of...

CIRCULATORY SYSTEM Tamethia Perkins MS, RRT-NPS, RRT-ACCS RT 3005/6005 BLOOD Cells – Erythrocytes – Leukocytes – Thrombocytes Plasma RBCs  Biconcave discs (7.5 diameter and 2.5 thickness). Contains the Hgb for O2 transport.  Produced in the bone marrow at a rate of 2 million cells/sec to compensate for RBC destruction (spleen and liver).  Life span is 120 days.  Major portion of blood cells.  ~4 -5 million RBCs/mm3.  Hematocrit: % of RBCs to total blood volume. Normal: 42%- 45%. – Newborn: 45-60%. RBC Hct Hct LEUKOCYTES  Primary function: protection against bacteria and foreign agents.  Two groups: – PMN granulocytes Neutrophils: more active in bacterial infection Eosinophils: allergic conditions Basophils – Mononuclear Monocytes: chronic infections Lymphocytes  5000-9000 cells/mm3 Blood Differential Count THROMBOCYTES (platelets) Smallest formed element in the plasma. 250,000-500,000 cells/mm3. Prevent blood loss upon endothelial injury. Platelet Platelet PLASMA Straw-colored liquid. 55% of total blood volume. Consists of: – 90% water – 10% proteins, electrolytes, hormones, etc. Plasma THE HEART  Hollow, 4-chambered, muscular organ.  2 atria, 2 ventricles. Blood Flow Through the Heart Blood Supply of the Heart Originates from the aorta by means of two coronaries: R and L. – L: divides into circumflex (lateral wall and diaphragmatic surface of LV) and anterior descending (ant wall of LV, septum) – R: RV and post portion of the septum. At rest, heart receives ~5% of CO. Blood Supply of the Heart Conductive System of the Heart  Autorhythmicity: heartbeat without external stimulus.  Components: – SA node – AV node – Bundle of His – R and L bundle branches – Purkinje fibers  ANS control of heart. Conduction Electrocardiogram  Recording of electrical impulses by means of electrodes placed on the body.  Changes and waves are reflection of the depolarization and repolarization of the cardiac muscle.  Waves: –P – QRS –T Depolarization and respolarization EKG