Cardiovascular Histo

Cardiovascular Histo

1. Vascular system

   • Vessels (Arteries-Viens-Capillaries)
   • Heart
     • Layers of the heart
       • Endocardium
         • 1- Simple squamous epithelium
           • 2- Subendothelium: Loose CT, continous with BV entering and leaving the heart
             • 3- Subendocardium: CT layer, which contains the conducting system
       • Myocardium
         • 1- Middle layer, which contains the cardiac muscle fibers
           • 2- It has CT surrounding the muscle fibers
       • Epicardium
         • 1- Simple squamous mesothelium
           • 2- Layer of CT & fats that contains Blood vessels & Nerves
     • Cradiac Muscle
       • LM picture
         • CT
           • Perimysium
             • CT of collagen & elastic fibers, Highly vascular, surrounds bundles of cardiac muscle fibers
           • Endomysium
             • A layer of reticular fiber, surrounding each cardiac muscle fiber
         • Cardiac fiber
           • Longitudinal cylindrical, which branch and anastamose
           • Has several short columnar cardiomyocytes that are joined together by intercalated discs
           • Has split-like spaces that appear in all cut sections
           • Has a singlar, oval nucleus
       • EM picture
         • Myofbrils
           • Not in register, hence, fainter than SM
           • Branch and anastamose, thus they diverge around the nucleus where there is sarcoplasm, Mitochondira and inclusions.
           • Design is like the SM
         • T-tubules
           • Extends from the sarcolemma, allows in the excitation coupling reaction
           • Provides more S.A for the exchange btw the ECF and muscle
         • Sarcoplasmic reticulum
           • Not well developed as in SM
           • Made u of narrow sarcotubules
           • Doesnt have terminal cisternae instead it forms diads between the Ttubules and sarcotubules
         • intercalated discs
           • Transverse
           • Longitudinal

2. Lymhatic system