17 Cartilage and Bones

Question 1

What are the three types of cartilage?

Answer 1

all matrix containing proteoglycan and hyaluronic acid
all have chondrocytes
hyaline, elastin and fibrocartilage.

Question 2

Hyaline cartilage
types of cell?
type of collagen?
how do they get nutrients?
BETWEEN JOINTS

Answer 2

matrix contains type 2 collagen. The hyaluronate proteoglycan aggregates are bound to the fine collagen matrix fibres.
Only has chondrocytes. divided into small clusters called isogenoous. pale area around the groups is called a lucuna.
at the articulating surface of some bones eg rib cage, nose, trachea, bronchi, larynx.
dont have a blood supply to it by extracellular matrix is so fluid that it allows easy diffusion. chondrocytes produce and maintain extracellilar matrix. although fluid, very strong. hyaluronic acid assists in getting water into cells/ helping it be resilient.
About 100 hyaluronic proteoglycan aggregates per collagen fibril

Question 3

how does hyaline cartilage grow?

Answer 3

grows from perichondrian. grows into chondroblasts and grow larger. they grow away from the edge: appositional growth.

Question 4

Elastic cartilage
what cells?
examples?

Answer 4

chondrocytes only

pinna of ear, eustachian tube and epiglottis. You know its elastic cus it rebounds

Question 5

Fibrocartilage
cell types?
Structure?
examples?
functions?

Answer 5

chondrocytes and fibroblasts.
fibrocartilage is a combo of dense regular connective tissue and hyaline tissue.
cells are often in rows. there is no surrounding perichondrium.
Examples: intervetebral discs, articular discs of the sternoclavicular and temporomandibular joints, the menisci of the knee joint and the pubic symphysis.
Function: shock absorber and resists shear force.

Question 6

Development of bones in embryo

Answer 6

from cartilage. hyaline cartilage model. grow by endochondral ossification.

grow from growth plate
middle of bone: osteocytes
side of bones: osteoblasts

Question 7

compostion of bone matrix

Answer 7

65% inorganic: calcium hydroxyapatite and magnesium salts. Helps to resist bending and compression forces.

35% organic: collagen 1, GAG & proteoglycans, non-collagenous proteins. important to resist pulling and tension force.

Question 8

Bone cells

Answer 8

Osteoprogenitor: undifferentiated cells that are found on the outside (periosteum) and inside of bone (endosteum).
Osteoblast: intermediate to the osteocyte. cannot divide. inner layer of endosteum and spicules.
Osteocytes: terminally differentiated bone cells. trapped withn osteon. maintain bones.
Osteoclast: huge cells (as many as 50 nuclei). its a fused monocytes. surface of cortical bone. job to break down bone.

Question 9

Osteoarthritis

Answer 9

age related degeneration

failure of the articular cartiglage: narrowing of the joint space

Question 10

Rheumatoid arthritis

Answer 10

Autoimmune disease

inflammation of synovial membrane thickening of the joint capsule