Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
HA Unit 2 Topic 1
| Term | Definition |
|---|---|
| Six functions of bone tissue | Support, protection, assists movement, mineral reserve, blood cell production, and triglyceride storage |
| Support | Function of bone: framework for the body and attachment point for muscles |
| Protection | Function of bone: protects soft internal organs. Examples: Skull protecting the brain |
| Assists movement | Function of bone: muscles need to be attached to stable structures in order to produce movement |
| Mineral reserve | Function of bone: stores calcium and phosphorus to help maintain homeostasis in their blood levels |
| Blood cell production | Function of bone: some bones have red marrow which produces red and white blood cells and platelets |
| Triglyceride storage | Function of bone: yellow bone marrow stores triglycerides for energy reserve |
| Tissues that make up bone | Osseous (bone), cartilage (fibrous connective tissue), connective (binding and support), epithelium (covering), adipose (fat), and nervous |
| Osseous tissue | Bone tissue |
| Bone as an organ | Each bone is considered an organ because it is made of several tissues, and each bone is continually remodeling |
| Long bone | Bone type with a diaphysis, epiphyses, and metaphyses. Examples: Femur, humerus, tibia, phalanges |
| Diaphysis | Shaft or long main part of a bone |
| Epiphyses | Distal and proximal ends of a bone (singular: epiphysis) |
| Epiphyseal plate | Area of cartilage in the epiphysis of a growing bone that allows for elongation; commonly called the growth plate |
| Epiphyseal line | Line that replaces the epiphyseal plate when the bone stops growing |
| Metaphyses | Regions where the diaphysis joins each epiphysis (singular: metaphysis) |
| Articular cartilage | Thin layer of hyaline cartilage that covers the epiphysis where a bone articulates (forms a joint) with another; slippery and absorbs shock |
| Articulate | To form a joint with another bone |
| Periosteum | Sheath surrounding the bone; its cells are bone-forming and add to the thickness of bone; also protects, nourishes, repairs, and serves as attachment for tendons and ligaments |
| Periosteum layers | Outer fibrous layer and inner cellular layer |
| Sharpey's fibers | Perforating fibers that act like thumb tacks to hold the periosteum to the bone |
| Medullary cavity | Space within the diaphysis that holds marrow |
| Endosteum | Thin membrane that lines the medullary cavity |
| Red marrow | Marrow that produces red blood cells, white blood cells, and platelets; located in spongy bone |
| Yellow marrow | Marrow that stores triglycerides (fat) for energy reserve; found in the medullary cavity |
| Nutrient arteries | Blood vessels that enter the bone to supply it with blood |
| Microscopic structure of bone | Bone has spaces that act as storage areas and canals for blood and nerve supply; bone is classified by the size and distribution of these spaces |
| Compact bone | Bone with few spaces that is very strong; found beneath the periosteum and makes up most of the diaphysis. Examples: Shaft of long bones |
| Cortical bone | Another name for compact bone |
| Perforating canals | Canals through which blood vessels, lymphatic vessels, and nerves penetrate compact bone |
| Spongy bone | Lighter, irregular lattice of bone; makes up more areas of flat bones and the epiphyses of long bones; red marrow is located here. Examples: Epiphyses of long bones, flat bones |
| Cancellous bone | Another name for spongy bone |
| Trabeculae | Thin plates of bone in the lattice that make up spongy bone |
| Two main types of bone cells | Osteoblasts and osteoclasts |
| Osteoblasts | Bone-building cells that secrete extracellular matrix and initiate calcification; become osteocytes |
| Osteocytes | Mature bone cells; form from osteoblasts |
| Lacuna | Small space in the bone matrix where an osteocyte sits |
| Canaliculus | Tiny channel in bone that connects osteocytes (plural: canaliculi) |
| Osteogenic cell | Bone stem cell found near the endosteum and periosteum that develops into an osteoblast |
| Osteoclasts | Cells concentrated in the endosteum that face the bone surface and release enzymes that break down bone matrix |
| Resorption | Breakdown of bone matrix by osteoclasts |
| Bone matrix | Hard extracellular material of bone that surrounds bone cells |
| Calcification | Hardening of extracellular matrix as calcium and other mineral salts are deposited |
| Ossification | Process of bone formation |
| Two types of bone formation | Intramembranous ossification and endochondral ossification |
| Intramembranous ossification | Bone formation where cells cluster where the bone will form and secrete extracellular matrix to begin calcification. Examples: Flat bones of the skull (frontal, parietal, parts of temporal and occipital), facial bones |
| Steps of intramembranous ossification | 1) Development of ossification center 2) Calcification 3) Formation of trabeculae 4) Development of the periosteum |
| Ossification center | Area where osteoblasts cluster and secrete organic extracellular matrix to begin forming bone |
| Mesenchyme | Embryonic connective tissue that develops into bone; at the outer edge of the bone it develops into the periosteum |
| Endochondral ossification | Bone formation by replacement of a fetal cartilage "scaffold" with actual bone. Examples: Long, irregular, and short bones |
| Hyaline cartilage model | Fetal cartilage "scaffold" that is replaced by bone in endochondral ossification |
| Bone collar | Ring of bone that forms around the diaphysis of the cartilage model during endochondral ossification |
| Primary ossification center | First site of bone formation, in the diaphysis, during endochondral ossification |
| Secondary ossification center | Later site of bone formation, in the epiphyses, during endochondral ossification |
| Increase in bone length | Diaphysis lengthens because of activity at the epiphyseal plate |
| Chondrocytes | Cartilage-forming cells; new ones form on the epiphyseal side of the growth plate while old ones on the diaphyseal side are replaced by bone |
| Epiphyseal plate damage | Damage to the epiphyseal plate during younger years can cause a bone to not reach its normal length |
| Salter-Harris IV fracture | Fracture through the epiphyseal plate that involves both the metaphysis and the epiphysis. Examples: Fracture of the distal tibial epiphysis and metaphysis at the ankle |
| Bone remodeling | Bones are always being remodeled; depends on intake of nutrients and presence of hormones |
| Bones under heavy loads | Bones subjected to heavy loads will grow thicker |
| Minerals needed for bone remodeling | Calcium, phosphorus, iron, manganese, fluoride, magnesium |
| Vitamins needed for bone remodeling | C, K, B12, A |
| Hormones needed for bone remodeling | Growth factors, androgens |
| Calcium reservoir | Bone is a major calcium reservoir that helps keep blood calcium in homeostasis |
| Normal blood calcium level | 9–11 mg/100 mL |
| Calcitonin | Hormone released by the thyroid gland when blood calcium rises; stimulates calcium salt deposit in bone, lowering blood calcium |
| Parathyroid hormone (PTH) | Hormone released by the parathyroid glands when blood calcium falls; causes osteoclasts to degrade bone matrix and release calcium into the blood |
| Thyroid gland | Gland that releases calcitonin when blood calcium levels rise |
| Parathyroid glands | Glands on the thyroid that release PTH when blood calcium levels fall |
Created by:
khondakerr