Module 5 - Cartilage and Bone Flashcards
Which of the following are true regarding compact and spongy bone?
-Each osteon is composed of concentric rings (lamellae) with a central canal containing blood vessels, nerves, and lymphatic vessels.
-The structural unit of compact bone is called an osteon.
-Spongy bone is denser and stronger.
-Trabeculae network spaces make bones lighter for movement.
-Compact bone contains trabeculae.
-Each trabecula forms along the lines of stress to provide strength to the bone.
-Each osteon is composed of concentric rings (lamellae) with a central canal containing blood vessels, nerves, and lymphatic vessels.
-The structural unit of compact bone is called an osteon.
-Trabeculae network spaces make bones lighter for movement.
-Each trabecula forms along the lines of stress to provide strength to the bone.
Sesamoid bone
Small and round; embedded in tendons
-vary in number and placement from person to person but are typically found in tendons associated with the feet, hands, and knees.
-The patellae are the only sesamoid bones found in common with every person.
Short bone
Cube-like in shape, approximately equal in length, width, and thickness; provide stability and support as well as some limited motion (ex. carpals, tarsals)
Flat bone
Thin and curved; serve as points of attachment for muscles and often protect internal organs (ex. cranial skull bones, scapulae, sternum, ribs)
Long bone
Cylinder-like shape, longer than it is wide; function as levers; they move when muscles contract (ex. bones in arms, legs, metacarpals, phalanges, metatarsals, etc)
Epiphysis
Wider section at the end of a long bone; filled with spongy bone
Medullary cavity
Hollow region in the diaphysis; filled with yellow marrow which is an important site for energy reserve
Metaphysis
Where the epiphysis meets the diaphysis; the narrow area that contains the epiphyseal plate (growth plate), a layer of hyaline cartilage in a growing bone
Diaphysis
Tubular shaft that runs between the proximal and distal ends of the bone
Fossa
Shallow basin-like depression
Facet
Flat articular surface
Foramen
Round or oval hole through a bone
Canal
Elongated passage in bone
Condyle
Large rounded articular surface
Head
Bony expansion carried on a narrow neck
Tuberosity
Large rounded projection, may be roughened
What is produced in the red bone marrow?
Blood cells
The periosteum covers the ____ of the bones
Outside
The outer layer of all bones are comprised of:
compact bone
How do the functions of the osteoclasts and osteoblasts differ?
Osteoclasts dissolve bone matrix, whereas osteoblasts deposit matrix into the bones.
Once the first blood vessels grow into the shaft of the cartilage in a developing bone, what occurs first?
Osteoblasts migrate into the cartilage with the capillaries and begin to lay down bone.
If you break your leg and wear a cast for two months, what changes will you expect to observe in the leg when the cast is removed?
The healed bone will have lost bone mass because it will not have been stressed.
Endochondral ossification begins with:
hyaline cartilage
During endochondral ossification:
-capillaries and osteoblasts migrate into the heart of the cartilage.
-osteoclasts erode the center of the new bone to form a marrow cavity.
-cells of the perichondrium differentiate into osteoblasts.
-the matrix of the cartilage model becomes calcified.
Appositional bone growth increases the dimensions of cartilage and bone by:
adding cells to the surface
Red marrow
-In some spongy bone in adults, medullary cavity in children
-Contains stem cells that produce all formed elements found in blood
Spongy bone
-Layer of bone tissue that has many small spaces and is found just inside the layer of compact bone.
-supports shifts in weight distribution
Trabeculae
contain layers of parallel lamellae and osteocytes; only found in spongy bone
Compact bone
-the denser, stronger of the two types of bone tissue
-found under the periosteum and in the diaphyses of long bones, where it provides support and protection.
Nutrient artery
large artery that supply the diaphysis enter through the nutrient foramen
Metaphyseal arteries
The blood supplies to/from the metaphysis
Epiphyseal artery
The blood supplies to/from the epiphysis
Periosteal arteries
The blood supplies to/from the periosteum
Periosteum
a fibrous membrane the outer surface of the bone is covered with; contains blood vessels, nerves, and lymphatic vessels that nourish compact bone
Endosteum
a delicate membranous lining the medullary cavity has; where bone growth, repair, and remodeling occur
Osteoclast
The cell responsible for bone resorption, or breakdown
Osteoblast
bone cell responsible for forming new bone and is found in the growing portions of bone, including the periosteum and endosteum
Osteocyte
what the osteoblast becomes as the secreted matrix surrounding the osteoblast calcifies and the osteoblast becomes trapped within it; thus, it changes in structure and becomes an osteocyte
Osteogenic (Osteoprogenitor) cell
bone stem cell that replaces the other cells in bone
Yellow Marrow
-where hematopoiesis, the production of blood cells, takes place
-Red blood cells, white blood cells, and platelets are all produced in the red marrow.
Osteon
The microscopic structural unit of compact bone; composed of concentric rings of calcified matrix called lamellae
Central canal
runs down the center of each osteon; contains blood vessels, nerves, and lymphatic vessels
Concentric Lamellae
rings of calcified matrix around a central canal
What is the difference between Circumferential lamellae and cocentric lamellae?
concentric lamellae form the cylindrical structure of an osteon, while circumferential lamellae run around the entire bone periphery.
Lacunae
small cavities in bone that contain osteocytes, mature bone cells
Canaliculi
microscopic chanels that connect with the canaliculi of other lacunae and eventually with the central canal.
Perforating canal
canal perpendicular to the central canal, carries blood vessels and nerves
Intramembranous ossification
-The flat bones of the face, most of the cranial bones, and the clavicles (collarbones are formed via intramembranous ossification.
-Bones formed directly from a membrane
of connective tissue
Endochondral ossification
the process of bone formation where hyaline cartilage is gradually replaced by bone; all of our bones are formed this way but the ones mentioned in intramembranous ossification
Periosteal bone collar
thin plate of compact bone surrounding the outer surface of the cartilage
Interstitial bone growth
-Growth in the middle
-Chondrocytes within cartilage divide and secrete a new matrix
-Cartilage only
Epiphyseal plate
-is the area of growth in a long bone
-it is a layer of hyaline cartilage where ossification occurs in immature bones
-On the epiphyseal side of the epiphyseal plate, cartilage is formed
-On the diaphyseal side, cartilage is ossified, and the diaphysis grows in length
Appositional bone growth
-Growth on the surface
-Increase in Diameter
-Bone and cartilage
Remodeling
the process of laying down new bone and resorbing old bone at the periosteal and endosteal surfaces
Rickets
Vitamin D deficiency in children (can cause bowed legs)
Osteomalacia
Vitamin D deficiency in adults; abnormal softening of the bone (can cause bowed legs)
Osteoarthritis
aging and stress result in decreased chondrocyte ability to maintain and repair its matrix; inflammation of bone and joint
Osteopenia
bone mineral density is lower than normal
Osteoporosis
rate of bone breakdown and reabsorption by osteoclasts is greater than production by osteoblasts ( a disease characterized by a decrease in bone mass that occurs when the rate of bone resorption exceeds the rate of bone formation, a common occurrence as the body ages.)
Irregular bone
does not have any easily characterized shape and, therefore, does not fit any other classification; tend to have more complex shapes, like the vertebrae that support the spinal cord and protect it from compressive forces
Pneumatized bone
-often hollow or contains numerous air pockets
-tend to be in skull and face
- decrease the weight of the skull and are often sites for the sinuse
-
Chondrocytes
cells that make up cartilage
Chondroblasts
progenitor cells that create cartilage
Hyaline cartilage
most common type of cartilage in the body, consists of short and dispersed collagen fibers; Provides stiff but somewhat flexible
support; reduces friction between bony surfaces (avascular)
-Between tips of ribs and bones of sternum; covering bone surfaces at synovial joints; supporting larynx (voice box), trachea, and bronchi; forming part of nasal septum
Fibrocartilage
Resists compression; prevents bone-to-bone contact; limits relative movement
-Pads (menisci) within knee joint; between pubic bones of pelvis; intervertebral discs
Elastic cartilage
Provides support, but tolerates distortion without damage and returns to original shape
-Auricle of external ear; epiglottis; auditory canal; cuneiform cartilages of larynx
Perichondrium
- layer of dense irregular connective tissue
-fibrous outer layer
-resists outward pressure
Articular cartilage
thin layer of cartilage that reduces friction and acts as a shock absorber.
Interstitial cartilage growth
expansion of cartilage from within by the division of existing chondrocytes, increasing the length of the cartilage
Appositional cartilage growth
involves the addition of new cartilage cells from the perichondrium at the surface, leading to an increase in the width of the cartilage
