Histology 🔬 Flashcards
What are the layers of the wall of the heart?
- Formed of 3 layers: Epicardium, myocardium & endocardium.
What is the myocardium formed of?
- The myocardium (the main substance of the heart) is formed of cardiac muscle fibers cut in all directions: L/S, T/S & oblique.
What is the moderator band?
- Group of purkinje fibers surrounded by C.T. sheath.
What differentiates Purkinje fibers from cardiac muscle fibers?
- Purkinje fibers are paler, larger than cardiac muscle fibers & have one or two peripheral nuclei.
What does the main part of moderator band consist of?
- The main part of the band consists of cardiac muscle fibers (T.S.)
What are the characteristics of the wall and the lumen of the Aorta?
- Thick wall & wide lumen.
What are the characteristics of the media, the Intima and the adventetia of the Aorta?
- Tunica media formed of fenestrated elastic membranes with only few smooth muscle fibers in between (forms the main thickness).
- Tunica intima is thin and not distinct from tunica media.
- Tunica adventitia is thin.
What is the color of the elastic membranes of tunica media of the aorta after staining with verhoeff’s stain?
- The fenestrated elastic membranes of the tunica media appear black in staining.
What are the characteristics of the media, the adventitia of IVC?
- Thin media formed of smooth muscle fibers only & there is no internal elastic lamina.
- The adventitia is thick containing bundles of longitudinally arranged smooth muscle fibers.
What are the characteristics of the wall and the media of medium sized artery and vein?
- The wall of the artery is thick & its wall is not collapsed in contrast to the vein.
- The media is thick in the artery but the adventitia is thicker in the vein.
How is preparation of blood film for microscopic study done?
- Spreading
2. Staining with Leishman’s stain
What is the shape of RBCs under the microscope?
- Rounded in shape, non nucleated.
- In the side view, they are biconcave disc-shaped cells. - Pinkish in the periphery with pale central area.
What is the shape of neutrophils under microscope?
- Multi-lobed nucleus (1-5 lobes).
- Numerous fine cytoplasmic granules.
What is the shape of basophils under microscope?
- Irregular nucleus (may be S-shaped).
- Few large basophilic granules masking the nucleus.
What is the shape of eosinophils under microscope?
- Bilobed nucleus (horse-shoe shaped).
- Numerous large acidophilic granules.
