Anatomy Review

Cheatsheet Content

### General Anatomy - **Types of Cartilage:** - **Hyaline:** Most common, found in articular surfaces, nose, trachea. Provides smooth surfaces for joint movement, support. - **Elastic:** Flexible, found in ear, epiglottis. Contains abundant elastic fibers allowing for bending and recoil. - **Fibrocartilage:** Strongest, found in intervertebral discs, menisci. Resists compression and tension, often found where strong support and shock absorption are needed. - **Types of Glands:** - **Exocrine:** Secrete products into ducts leading to internal or external surfaces. Examples: salivary glands (serous, mucous, mixed), sweat glands (eccrine, apocrine), sebaceous glands, pancreas (exocrine portion for digestion). - **Endocrine:** Ductless, secrete hormones directly into the bloodstream (e.g., thyroid, adrenal, pituitary glands). - **Reticular Fibers of Collagen:** - Delicate, branching fibers forming networks (stroma). Primarily composed of Type III collagen. Function to provide structural support for soft organs with many cells, such as lymphatic organs (lymph nodes, spleen), liver, and bone marrow. - **Types of Joints:** - **Structural Classification (based on material binding bones and presence/absence of joint cavity):** - **Fibrous Joints:** Bones United by fibrous tissue. No joint cavity. - **Sutures:** Immovable, found only in the skull. (e.g., coronal suture). - **Syndesmoses:** Bones connected by ligaments. Slightly movable (e.g., distal tibiofibular joint). - **Gomphoses:** Peg-in-socket fibrous joint. (e.g., tooth in alveolar socket). - **Cartilaginous Joints:** Bones united by cartilage. No joint cavity. - **Synchondroses:** Bones united by hyaline cartilage. Immovable (e.g., epiphyseal plates young long bones, costochondral joints). - **Symphyses:** Bones united by fibrocartilage. Slightly movable (e.g., pubic symphysis, intervertebral discs). - **Synovial Joints:** Most common and most movable. Characterized by: - **Articular Cartilage:** Hyaline cartilage covering bone ends. - **Joint Cavity:** Space containing synovial fluid. - **Articular Capsule:** Fibrous layer and synovial membrane. - **Synovial Fluid:** Lubricates and nourishes articular cartilage. - **Reinforcing Ligaments:** Strengthen the joint. - **Nerves and Blood Vessels.** - **Functional Classification of Synovial Joints (based on shape of articular surfaces and movement allowed):** - **Plane (Gliding):** Flat articular surfaces, allows short gliding movements (e.g., intercarpal, intertarsal joints). - **Hinge:** Cylindrical projection of one bone fits into a trough-shaped surface on another, allows flexion/extension (e.g., elbow, knee, interphalangeal joints). - **Pivot:** Rounded end of one bone protrudes into a ring of another bone, allows rotation (e.g., atlantoaxial joint, proximal radioulnar joint). - **Condyloid (Ellipsoidal):** Oval articular surface of one bone fits into oval depression of another, allows angular movements (flexion/extension, abduction/adduction, circumduction) but not rotation (e.g., radiocarpal joint, metacarpophalangeal joints). - **Saddle:** Each articular surface has both concave and convex areas, shaped like a saddle, allows greater freedom for biaxial movement (e.g., carpometacarpal joint of the thumb). - **Ball-and-Socket:** Spherical head of one bone fits into a cuplike socket of another, most freely moving type, allows all angular movements and rotation (e.g., shoulder, hip joints).