Special Pathology

The Heart Normal Structure 1. Anatomy and Physiology Heart Function : Muscular pump that circulates blood through the body. Weight : Adult Male: 300-350 gm Adult Female: 250-300 gm Chambers : Right Atrium and Left Atrium (superior) Right Ventricle and Left Ventricle (inferior and larger) Septa: Interatrial septum : Thin wall between atria. Interventricular septum : Thick wall between ventricles. Wall Thickness: Right Ventricle : 0.3–0.5 cm Left Ventricle : 1.3–1.5 cm 2. Blood Flow Pathway Systemic veins → Right atrium → Right ventricle → Pulmonary arteries → Lungs → Pulmonary veins → Left atrium → Left ventricle → Aorta → Systemic arteries 3. Cardiac Valves Atrioventricular (AV) Valves : Tricuspid valve (right) Mitral/Bicuspid valve (left) Semilunar Valves  : Pulmonary valve Aortic valve 4. Wall Layers of the Heart Epicardium (Visceral Pericardium) : Outer covering Myocardium : Muscle l...

HISTOTECHNOLOGY  Histological technique deals with the preparation of tissues for microscopic examination. The aim of good histological technique is to preserve the microscopic anatomy of the tissues and make them hard, so that very thin sections (5 microns) can be made. After staining, these sections should represent the anatomy of the tissue as closely as possible to their structure in life. This is achieved by passing the total or selected part of the tissue through a series of processes. These processes are:   Fixation   Dehydration   Clearing   Embedding Cutting   Staining   FIXATION  This is the foundation for the subsequent stages in the preparation of sections necessary for making a diagnosis. This is the process by which the constituents of the cells and tissues are fixed in a physical and also partly in a chemical state, so that they will withstand subsequent treatment with various reagents with a minimum l...

Blood Vessels and Their Structure 🔄 General Function of Blood Vessels Blood vessels form a closed circuit for blood to circulate throughout the body. Oxygen-rich blood is pumped from the left side of the heart , travels to all body cells, and returns oxygen-poor blood to the right side of the heart . 🛤️ Types of Blood Vessels Blood travels through the following vessels in order: Arteries – carry blood away from the heart. Arterioles – smaller branches of arteries. Capillaries – the smallest vessels where exchange of gases and nutrients occurs. Venules – small veins collecting blood from capillaries. Veins – carry blood back to the heart. 🧠 Arteries: Structure & Types Arteries are classified based on size and wall structure into: Type Key Features Large (Elastic) Rich in elastic tissue . Example: Aorta. Medium (Muscular) Rich in smooth muscle . Example: Coronary arteries. Arterioles Smallest arteries, control blood flow...