LAB4 Flashcards
(109 cards)
what does the skeletal system do?
- supports the weight of the body
- works together with the muscles to maintain body position and produce controlled movements
- involved in mineral
and lipid storage (mineral homeostasis) - site of blood cell production (hemopoiesis)
- protects organs from physical damage
how do bones respond to stresses placed on them?
growing thicker and stronger with exercise or becoming thin and brittle with inactivity
what bone tissues are adult bone made up of?
compact bone tissue and spongy bone tissue
what is the central canal?
Central region of osteon containing blood vessels and nerves
- blood vessels, nerves, and lymphatic tissue allows bone to receive nutrients, remove wastes, and be controlled by the nervous system
what are bone lacunae?
Spaces between lamellae that house osteocytes
what are osteocytes?
Mature bone cells that maintain bone (i.e., maintains metabolic processes such as nutrient/waste exhange with blood)
what are concentric bone lamellae?
Ring-shaped layers of collagen and calcified extracellular matrix
what are bone canaliculi?
Small canals between lacunae that connect osteocytes; provides osteocytes with nutrients and a pathway for communication
what are bone trabeculae?
Functional unit of spongy bone; arranged in an irregular lattice to make space for red bone marrow
what are osteoblasts?
immature osteocytes, build bone (bone deposition); secretes extracellular matrix and initiates calcification
what do osteoclasts do?
remodel bone through bone resorption
what is the function of the osteocyte’s cytoplasmic extensions?
Allows osteocytes to communicate with each other for processes such as movement
- Runs throughout canaliculi of bone to other osteocytes (connected by gap junctions)
where is spongy bone tissue found?
Hip bones, ribs, sternum, skull
Where do the osteocytes of spongy bone obtain their nutrients and oxygen, since there is no
central (Haversian) canal?
Red and yellow bone marrow have many blood vessels that give osteocytes in spongy bone nutrients and oxygen.
what is the function of red bone marrow?
- produces red blood cells, white blood cells, and platelets via hemopoiesis
- Mainly composed of developing blood cells, adipocytes, macrophages, and fibroblasts
what is the function of yellow bone marrow?
- Stores triglycerides, which are a potential chemical energy reserve - Mainly made from adipocytes
which adult bones contain red bone marrow?
hip bones, ribs, sternum, vertebrae, skull, ends of humerus and femur
what are the epipheses?
Proximal and distant ends of bone; primarily functions to form joints with other bones or attachments to muscles.
what is the diaphysis/shaft?
Long, cylindrical, main portion of bone. Provides the bone with strong support without too much weight.
what is the periosteum?
- layer of connective tissue surrounding bone
- Outer fibrous layer of dense connective tissue protects bone
- inner osteogenic layer is composed of osteopregenitor cells (area of bone production)
- Nourishes the bone through periosteal arteries (provides nutrients)
what is the endosteum?
Thin membrane lining medullary cavity and internal spaces of spongy bone
- Contains single layer of osteoregenitor cells and some connective tissue
what are osteoprogenitor cells?
bone stem cells, usually found in areas of bone production
what is the medullary cavity?
Hollow, cylindrical region within diaphysis
- Contains yellow bone marrow and blood vessels (blood vessels give nutrients to the bone)
- Allows bone to be strong while minimizing weight
what is the epiphyseal plate/line?
Area in each epihphyses consisting of hyaline cartilage, which allows the diaphysis to grow in length via endochondral ossification