Posts

The Respiratory System

  LUNGS – NORMAL STRUCTURE Anatomy Right lung: 375–550 g (avg. 450 g), 3 lobes (upper, middle, lower), 2 fissures . Left lung: 325–450 g (avg. 400 g), 2 lobes (upper, lower), 1 fissure . Middle lobe represented by lingula . Airway pathway: Trachea → Right/Left Main Bronchi → Segmental bronchi → Terminal bronchioles → Acinus (functional unit). Acinus structure: Respiratory bronchioles (3–5 generations) Alveolar ducts Alveolar sacs (alveoli) Pulmonary lobule: Cluster of 5 acini. Airway Wall Composition Trachea/bronchi: Cartilage, smooth muscle, mucous glands . Bronchioles: Smooth muscle only ; no cartilage/mucous glands . Blood Supply Dual supply: Pulmonary arteries: Deoxygenated blood. Bronchial arteries: Oxygenated blood. Lymphatics: Subpleural plexus → Hilar/tracheobronchial nodes → Thoracic duct. 🧬 Histology Bronchi/Bronchioles: Lined by pseudostratified ciliated columnar epithelium with goblet cells (decreas...
Post a Comment
Read more

The Urinary System

KIDNEY 1. Gross Anatomy Kidneys are bean-shaped paired organs . Weight : ~150 gm in adult males, ~135 gm in adult females. Located on either side of the vertebral column. Hilum (on medial side): Entry/exit for renal artery, vein, lymphatics, and ureter. Surrounded by a thin fibrous capsule (especially adherent at the hilum). 2. Gross Internal Structure Cut surface reveals three main parts : Cortex (outer): ~1 cm thick. Contains all glomeruli and ~85% of nephron tubules. Columns of cortex between pyramids: Renal columns of Bertin (contain interlobar arteries). Medullary rays : Striated structures in cortex made of straight tubules headed to the medulla. Medulla (inner): Contains 8–18 renal pyramids (cone-shaped). Base of pyramid: Cortico-medullary junction. Apex (renal papilla): Opens into minor calyces for urine drainage. Renal Pelvis (innermost): Funnel-shaped collecting area . Minor calyces (8–18): Collect urine from papillae...
Post a Comment
Read more