Chapter 6
Explain how cartilage grows.
1. Appositional Growth- "growth from outside" Addition of new layers onto those already formed. 2. Interstitial Growth- "growth from inside" Chondrocyte divide and secrete new matrix, expanding the cartilage from the inside.
Describe the functional properties of the three types of cartilage tissue.
1. Hyaline Cartilage- most abundant, support with flexability and resilience. Includes articular (covers bone ends), costal (connects ribs), respiratory, and nasal. 2. Elastic Cartilage- Has more stretchy fibers, able to stand repeat bending. Only found in external ear and epiglottis. 3. Fibrocartilages- Great tensile strength. Rows of chondrocytes alternating with thick collagen fibers. Found in knee cartilage and vertibrae discs.
Compare and contrast the structure of the four bone classes and provide examples of each class.
1. Long bones- Longer than they are wide. All limb bones besides the kneecap, wrist, and ankle. (arm, forearm, thigh, leg, palms, soles, fingers & toes) 2. Short bones- cube shaped - carpals (wrist) and tarsals (ankle) --Sesamoid bones- develop inside tendons (patella/kneecap) 3. Flat bones- Thin, flat, usually a bit curved. (most skull, sternum, ribs & scapulae) 4. Irregular bones- Fit no other class. (vertebra and hip)
Describe the gross anatomy of a typical long bone and flat bone. Indicate the locations and functions of red and yellow marrow, articular cartilage, periosteum, and endosteum.
1. Short, flat, and Irregular bones- Thin plates of spongy bone (dipole) covered by compact bone. Covered inside and outside by connective tissue membrane called periosteum and endosteum. 2. Long Bone- Contains the shaft (diaphysis) which holds yellow marrow. Bone ends (epiphyses) which are covered with articular cartilage. Membranes (periosteum) coves the external surface of the entire bone. 3. Red Marrow found within trabecular cavity (spongy bone) of long bones and in the dipole of short bones.
List and describe five important functions of bones.
1. Support, movement, and protection. 2. Store minerals, calcium and phosphate. 3. Blood cell formation, triglyceride (fat) storage, and hormone production (osteocalcin- protects against fat, glucose, and diabetes)
Indicate the functional importance of bone markings.
Serve as sites of muscle, ligament and tendon attachment. Projections - Bulge outwards Depressions & Openings - allow nerves and blood to pass. Tuberosity - large rounded projection, may be roughened Crest - Narrow ridge of bone Trochanter - Very large, blunt irregularly shaped process (only on femur) Line - narrow ridge of bone, less prominent Tubercle - small rounded projection or process Epicondyle - raised area above the condyle Spine - sharp slender, pointed projection Process - any bony prominence
