Marieb Chapter 6-8 Bones, joints, skeletal
Chapter 6-8 pertaining to bones and skeletal tissues, as well as joints and skeleton
Terms in this set (59)
small space or cavity in bone or cartilage that are occupied by cells
long, short, flat, or irregular
thin flattened and usually a bit curved; sternum, scapulae, ribs, most skull bones
Haversian system (osteon)
a system of interconnecting canals in the microscopic structure of adult compact bone; conduits for nerve, blood, and lymphatic vessels also act as tiny weight bearing pillars
small hair-like canals extending from the central canal. Allow for diffusion of nutrients, waste products, hormones, etc. to lacunae.
central (Haversian) canal
runs through the core of each osteon and contain small blood vessels and nerve fibers that serve need of the osteons cells
Paired, broad, flattened plates that extend from the pedicles and fuse at the midline to form the posterior vertebral arch.
What is an osteon?
=structural unit of the compact bone
Name the 5 types of bone cells:
-osteogenic (bone stem cells)
-osteoblast (matrix synthesizing cells)
-osteocyte (matrix maintenance cells)
-bone lining cells (line surfaces where no activity is ongoing)
-osteoclasts (bone destruction cells)
What does an osteon consist of?
central canal surrounded by concentric lamellae of bone matrix; osteocytes, embedded in lacunae, are connected to each other and the central canal by canaliculi
Describe spongy bone:
has slender trabecullae containing irregular lamellae, which enclose red marrow filled cavities
What is the chemical composition of bone?
Living cells and matrix
What does the extracellular matrix include?
-osteoid, organic substances that are secreted by osteoblasts and give the bone tensile strength. Its inorganic (mineral) component (=hydroxyapatites or calcium salts) make the bone hard
name the 2 types of ossification;
-intramembraneous (forms clavicles and most skull bones)
How are most bones formed?
via endochondral ossification of hyaline cartilage
Describe endochrondral ossification:
Osteoblasts beneath the periosteum secrete bone matrix on the cartilage model, forming the bone collar. As the cartilage model deteriorates, internal cavities open up, allowing periosteal bud entry. Bone matrix is deposited around the cartilage remnants but is later broken down.
How do long bones increase in length?
by interstitial growth of the epiphyseal plate cartilage and its replacement by bone
What does appositional growth increase?
it increases the bone diameter/thickness
What hormone is released when calcium levels decline?
What does PTH accomplish/
When calcium levels decline, PTH is released and stimulates osteoclasts to digest bone matrix, and therefore releasing ionic calcium
Name the 3 types of skeletal cartilage
contains thick collagen fibers, are the most compressible cartilage, resist stretching, form the intervertebral discs and knee joint cartilage, chondrocytes show parallel rows
Describe elastic cartilage.
contain abundant elastic fibers in addition to collage fibers. more flexible than hyaline cartilage. Support outer ear and epiglottis,
Describe Hyaline Cartilage
appear glossy, fibers are collagenous, chondrocytes are spherical, provide support with flexibility and resilience, most abundant skeletal cartilage. they account for articular, costal, respiratory and nasal cartilages
Describe skeletal cartilage.
exhibits chondrocytes housed in lacunae (cavities) within the extracellular matrix. contains large amount of water, lacks nerve fibers, is avascular, surrounded by perichondrium that resists expansion
components of axial skeleton
long axis of the body, includes the bones of the skull, vertebral column, and rib cage.
contrast axial skeleton to appendicular skeleton
axialskeletons dial is involved in protecting, supportingnorncarrying other body parts while the appendicular is involved in locomotion and manipulation of our environment
what does it mean that cartilage grows by interstitial growth?
lacunae-bound chondrocytes divide and secrete new matrix, expanding the cartilage from within
function of bones
support, protect, movement, mineral and growth factor storage, blood cell formation (in marrow cavity), triglyceride storage (in marrow cavity).
elongated shaft of a long bone
yellow marrow cavity
medullary (middle or marrow) cavity of the diaphysis that contains fat, in adults.
remnant of the epiphyseal plate
disc of hyaline cartilage that grows during childhood to lengthen the bone.
dense outer layer of bone.
internal layer of skeletal bone; honeycombed and filled with red or yellow marrow.
double layered membrane surrounding entire bone except joint surfaces;outer layer is dense fibrous irregular cartilage tissue; inner layer is osteogenic and touches the bone surface; is made of osteoblasts and osteoclasts; is innervated, vascular; is anchor point for tendons and ligaments
bone forming cells
large cells that resort or break down bone matrix
mature bone cell
perforating (Sharpey's) fibers
collagen fibers that extend from the periosteum's fibrous layer into the bone matrix
stem cells that give rise to osteoblasts
thin cartilage tissue that covers internal surfaces of the bone; made of osteoblasts and osteoclasts
cavity within the shaft of the long bones filled with bone marrow
hematopoietic tissue found in the trabecular cavities of spongy bone of long bones and diploe of flat bones
lamella (lamellae - plural)
make up concentric tubes, like growth rings on tree trunk
perforating (Volkmann's) canals
At right angles to the central canal, connects blood vessels and nerves of the periosteum and central canal and the medullary cavity
strut or thin plate of bone in spongy bone
irregularly shaped bone anterior to the sphenoid; forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls
abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium (bone resorption outpaces bone deposit); most common in post menopausal women
What is the general structure of a vertebrae?
each vertebrae (except c1-2) have a body, 2 transverse processes, 2 superior and 2 inferior articular processes, a spinous process, and a vertebral arch
How is the vertebral column constructed/
7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, coccyx, sacrum
Name the 8 bones of the skull:
-2 parietal bones
-2 temporal bones
-1 occiput bone
-1 frontal bone
-1 ethmoid bone
-1 sphenoid bone
Classification of joints
-structurally as fibrous, cartilaginous, synovial
-functionally as synarthrotic, amphiarthrotic, diarthrotic
Describe Fibrous joints:
occur where bones are connected to fibrous tissue; no joint cavity is present. All fibrous joints are synarthrotic; e..g sutures, syndesmoses, gomphoses
Describe cartilaginous joints;
bones are united by cartilage; no joint cavity is present; e.g. synchondroses (=synarthrotic) and symphyses (=amphiarthrotic)
Describe synovial joints:
most body joints are synovial joints; all are diarthrotic; have joint cavity.
What is a bursa?
=fibrous sac lined with synovial membrane and containing synovial fluid.
what is a tendon sheath?
= similar to a bursa, but is a cylindrical structure that surrounds muscle tendons