Shared Flashcard Set

Details

Histology of Bone and Cartilage
Some cards on the histological features of bone and cartilage
40
Histology
Professional
01/31/2015

Additional Histology Flashcards

 


 

Cards

Term
What are the three types of cartilage?
Definition
Hyaline
Elastic
Fibrocartilage
Term
Which type of cartilage is most abundant in the embryo?
Definition
Hyaline
Term
What type of cartilage is found in the auricle, epiglottis and auditory tubes?
Definition
Elastic
Term
Where can you find fibrocartilage?
Definition
Intervertebral discs and pubic symphysis.
Term
What is the primary cell type of hyaline cartilage?
Definition
Chondrocytes
Term
What is a lacunae?
Definition
It is the space in which chondrocytes live.
Term
What is the primary fiber type of hyaline cartilage?
What other types of fibers exist?
Definition
Collagen Type II. It is produced by chondrocytes.
The others include collagen type IX, X, and XI
Term
True or false: cartilage is highly vascular
Definition
Unlike bone, cartilage is avascular and must receive its nutrients from diffusion.
Term
What is the perichondrium?
Definition
It is a dense irregular connective tissue which contains chondroblasts. They differentiate into chondrocytes and add a new layer the outside.
Term
When referring to cartilage, what is referred to as the matrix?
Definition
It is a darker staining area around the lacunae that has a higher concentration of proteoglycans. It is called the matrix or capsule.
Term
Describe the processes of appositional growth and interstitial growth
Definition
Appositional growth is on the surface of cartilage and adds new layers outward.

Interstitial growth is through the division of chondrocytes.
Term
What is the name for a cluster of chondrocytes?
Definition
isogenous groups.
Term
What is the main difference between elastic and hyaline cartilage when viewed under the light microscope?
Definition
Elastic cartilage has elastic fibers.
Term
What is the main way to differentiate fibrocartilage via the light microscope?
Definition
Chondrocytes will cluster in lacunae and be very spread out with lots of fibers between them. Or, they will be more abundant and stain very darkly, darker than the surrounding elastic cartilage
Term
What is the precursor to bone?
Definition
Hyaline cartilage.
Term
What are the four types of bones?
Definition
Long bones: Cylindrical in shape

Short bones: Mostly spongy bone and the width is similar to the length

Flat bones: Thin, flat, and slightly curved with two layers of compact bone surrounding spongy bone.

Irregular bones: Do not fit any other type. Examples include hip bones and vertebrae
Term
What makes up bony matrix?
Definition
Calcium phosphate mostly. Also has type 1 collagen, clycosaminoglycans, and glycoproteins.
Term
What is the epiphyseal line?
Definition
It is a line where bones grow during childhood. It is a region of hyaline cartilage that will eventually be replaced with bone.
Term
What is the end of a bone called?
Definition
Epiphysies
Term
What is the diaphysis of a bone?
Definition
It is the shaft of a long bone.
Term
What is the periosteum?
Definition
A double layer of dense irregular connective tissue that covers everything but the joint surfaces.
Term
What happens to bone as it becomes vascular?
Definition
It calcifies.
Term
What are lamella?
Definition
They are concentric rings of bony matrix forming the tubes of an osteon
Term
What is a haversion canal?
Definition
It is a central canal that contains blood vessels and nerve fibers.
Term
What is a volkmann's canal?
Definition
They are perferating canals that run perpendicular to haversion canals to connect adjacent haversion systems.
Term
What cells are involved in bone remodeling?
Definition
Osteoblasts, osteocytes, fibroblasts, and osteoclasts.
Term
What do osteoblasts do?
Definition
They are progenitor cells that mature into osteocytes. They secrete collagen I
Term
What do osteoclasts do?
Definition
They resorb bony matrix to harvest calcium
Term
What are canaliculi?
Definition
they are small canals that connect osteocytes to other osteocytes and allow for communication and diffusion of nutrients.
Term
What do osteocytes do?
Definition
They maintain the bone matrix.
Term
Where do you find osteoclasts?
Definition
They sit in a depression called a howship lacunae, which has a ruffled border.
Term
What stimulates osteoclast to resorb calcium?
Definition
Parathyroid hormone.
Term
What inhibits osteoclast activity?
Definition
Calcitonin.
Term
From what cell line are osteoclasts derived?
Definition
Monocytic.
Term
What determines the rate of bone remodeling?
Definition
Bones under stress are remodeled faster.
Term
What makes up the bony matrix of intramembranous bones?
Definition
Osteoid, which is released from osteoblasts.
Term
What are the zones of bone growth in order?
Definition
Zone of reserve cartilage
Zone of proliferating cartilage
Zone of hypertrophy
Zone of calcifying cartilage
Zone of erosion
Zone of Newly formed bone
Term
What is spongy bone?
Definition
It makes up the interior of bones and has a meshed network of traveculae
Term
Describe the process of endochondral ossification
Definition
First blood vessels enter the perichondrium

Nutrients reach mesenchymal cells, which differentiate into osteoblasts.

Osteoblasts form a bony collar, which eventually forms an impenetrable barrier.

Condrocytes die, which leaves gaps in calcified cartilage

Cartilage that is not encapsulated continues to grow and make a model for bone growth.

Osteoclasts come in, and make space for other tissues (arteries, veins, lymphatics, bone marrow, etc)

Osteoblasts secrete osteoid to surround the remaining hyaline cartilage

The last step is the formation of secondary ossification centers at the proximal and distal epiphyses in long bones.
Term
Describe the process to bone fracture healing
Definition
First a hemotoma forms

Then a fibrocartilage callus forms.

Fibroblasts lay down collagen fibers to close the fracture

Osteoblasts lay down spongy bone

Some osteoblasts become osteocytes to lay down matrix to be calcified.

Boney callus forms. Osteoblasts replace cartilage with trabeculae

Bone is remodeled by osteoclasts and blasts which lay down compact bone which resembles the original due to undergoing the same stresses.
Supporting users have an ad free experience!