Nerve Plexuses Present in the GIT 1. Myenteric Plexus (Auerbach’s plexus) Location: Between the circular and longitudinal layers of muscularis externa Function: Controls motility of the gut Regulates peristalsis Controls muscle tone and coordination Clinical note: Affected in achalasia and Hirschsprung disease 2. Submucosal Plexus (Meissner’s plexus) Location: In the submucosa Function: Controls secretion Regulates local blood flow Influences absorption One-Line Exam Answer Two nerve plexuses are present in the GIT: Myenteric (Auerbach’s) plexus and Submucosal (Meissner’s) plexus. Quick Handwritten-Style Memory Table Myenteric (Auerbach) → Movement Submucosal (Meissner) → Secretion
Ankylosing spondylitis (AS) is a chronic, inflammatory rheumatic disease that mainly affects the axial skeleton, especially the sacroiliac joints and spine . Over time, persistent inflammation can lead to new bone formation , spinal stiffness, and eventual fusion of vertebrae . What happens in ankylosing spondylitis Inflammation starts at entheses (sites where ligaments and tendons attach to bone) Recurrent inflammation causes pain and stiffness Healing occurs with abnormal bone formation, leading to ankylosis (fusion) Key clinical features Inflammatory low back pain Onset before 40 years Insidious onset Morning stiffness lasting more than 30 minutes Improves with exercise, not with rest Reduced spinal mobility Chest expansion reduced Peripheral arthritis (hips, shoulders) Extra-articular features: Acute anterior uveitis Aortitis and aortic regurgitation (rare) Apical lung fibrosis (late) Etiology and risk factors Strong genetic association with HLA-B27 More common in young ma...