Exam 2 Flashcards
How many bones do humans have at birth?
270
List all 6 functions of the skeletal system.
- Support
- Protection
- Movement
- Electrolyte/acid-base balance
- Blood cell production
- Hormone production
What are the 4 different bone shapes?
- Long bones
- Short bones
- Flat bones
- Irregular bones
Define: Trabeculae
Small needle-like pieces in the medullary cavity
Define: Diaphysis
Shaft of the bone
Define: Medullary cavity
Central canal surrounded by a collar of compact bone
Define: Epiphyses
The ends of a bone, are covered with articular cartilage
Define: Epiphyseal plate
The growth plate of hyaline cartilage where bone growth occurs during childhood. Seals and becomes the epiphyseal line in adulthood. (revisit this one for more detail)
Define: Metaphysis
Epiphyseal plate or line
Define: Periosteum
Double-layered membrane around bones
Describe the two layers of the periosteum.
- Fibrous layer: outer layer of dense irregular connective tissue
- Osteogenic layer: inner layer, contains osteoblasts and osteoclasts
The periosteum is richly supplied by nerve fibers, lymphatic vessels, and blood vessels.
Describe the general function of osteoblasts and osteoclasts.
-Osteoblast: secrete osteoid, deposit blood
-Osteoclast: break down blood using HCl
Define: Perforating fibers
Tufts of collagen that extend from the fibrous layer to the bone
Define: Endosteum
Delicate connective tissue membrane; covers trabeculae and canal system in compact bone
Define: Diploe
Endosteum covered trabeculae of spongy bone, only found in the skull
Describe hematopoietic tissue.
AKA red marrow, is found in trabecular cavities of long and short bones. In infants, all bone marrow is red marrow. However in adulthood, blood is only produced in the head of the femur and humerus, flat bones, and some irregular bones.
Osteogenic cells give rise to______.
Osetoblasts
Define: Osteocytes.
Former osteoblasts that have become trapped inside the matrix they produced.
Define: Canalicluli
The structures that connect lacunae (revisit this one)
Osteoclasts have multiple ________.
Nuclei
Describe osteoid.
Osteoblast secretion, makes up 1/3 of the matrix in bone. Made up of collagen fibers and ground substance.