Cartilage and Bone Flashcards
What type of tissue are cartilage and bone?
Connective tissues
What are the 2 types of bone?
Flat and long
What are 4 functions of bone?
- Protection
- Locomotion
- Mineral reservoir
- Blood cell production
Where is cartilage usually found and what is its primary function?
At bone ends.
Locomotion.
What is the function of flat bones?
Give 3 examples of flat bone.
Protection of internal organs.
Ribs, sternum, and skull.
What is the function of long bones?
Give 2 examples of long bones.
Support weight and allow movement.
Femur and humerus.
What is the osteoid?
The unmineralised, organic portion that makes up 30% of bone in the ECM
What is osteoid composed of?
Type I collagen
What crystals give the bone strength and rigidity?
Calcium and phosphate hydroxyapatite crystals
Which cells synthesise and secrete bone matrix/osteoid?
Osteoblasts
What is the function of osteoblasts?
Synthesis and secretion of bone matrix
From where are osteoblasts derived?
Osteoprogentior cells
Which cells maintain bone matrix?
Osteocytes
What is the function of osteocytes?
Maintenance of bone matrix
What are lacunae? What cell type gets trapped within them and changes names?
Gaps/spaces in the bone matrix.
As matrix is synthesised, osteoblasts become trapped as osteocytes.
What are osteocytes?
Inactive osteoblasts trapped in the bone they formed
Which cells resorb bone and release calcium into the bloodstream?
Osteoclasts
From where are osteoclasts derived?
Monocyte cell line
What is the periosteum?
A dense layer of connective tissue that surrounds the outer surface of bones
Where is the periosteum not found?
At the surfaces of joints
What structure do trabeculae form and what does this mean for the movement of bones and muscles?
Forms a lattice network that makes bones lighter, allowing them to be moved easily by muscles.
What are trabeculae?
Bands of connective tissue that form along stress lines to provide strength
What is the cortical bone?
Dense outer layer
What makes up the inner layer of bone?
Spongy cancellous bone / trabeculae
What is haematopoiesis?
The production of new blood cells to balance out the loss of mature blood cells.
Where is the site of haematopoeisis?
Red/yellow bone marrow
What is the endosteum?
The thin inner membrane that separates the bone from marrow
What is the thin inner membrane separating bone and marrow?
The endosteum
What is the dense layer that surrounds the outer surface of bone?
The periosteum
What is the dense outer layer?
Cortical bone
What are the structural units that cortical bone is composed of?
Osteons
What are osteons composed of?
Layers called lamellae
What do osteons have and what is contained within these structures?
Central canals.
Contains nerves, capillaries, and lymphatics
What are the 3 lamellae layers formed during osteon development?
- Concentric
- Interstitial
- Circumferential
Describe the 4 steps of osteon development
- Osteoclasts resorb a wide channel (the central canal)
- Nerves, capillaries, and lymphatics grow into the channel
- Osteoblasts line channel and lay down osteoid
- Osteoid is mineralised and osteoblasts are trapped in lacunae as osteocytes
What are the 2 layers of periosteum?
Outer and inner
What is outer periosteum and what does it contain?
Dense, irregular fibrous tissue
Contains blood, lymphatics, and nerves
What is inner periosteum and what does it contain?
What does it give rise to?
A cellular layer next to the bone surface
Contains osteogenic cells
Gives rise to circumferential lamellae
What are the 3 types of cartilage?
Hyaline
Fibrocartilage
Elastic
Is cartilage highly vascular or avascular?
Avascular
Which cells maintain the integrity of cartilage?
Chondrocytes
Which cells synthesise and secrete cartilage ECM?
Chondroblasts
How do cartilage cells receive nutrients if cartilage is avascular?
Cartilagenous matrix diffuses metabolites
What is the perichondrium?
A connective tissue that envelops cartilage that is not at a joint
What is the connective tissue that envelops cartilage tissue that is not at a joint
the Perichondrium
On what surface type is cartilage usually found? Where is this?
Atricular surfaces.
=on joints
What does hyaline cartilage contain?
Abundant gel ground substance
What does hyaline cartilage provide?
A smooth surface that allows tissues to easily move over each other
What is fibrocartilage a mix between?
Hyaline cartilage and dense fibrous tissue
Where is fibrocartilage found?
Vertebral discs and joints
What does fibrocartilage contain?
What do they provide?
Abundant collagen fibres
Provides strength
What does elastic cartilage provide?
Structural support and flexibility
What are elastic fibres synthesised by?
Chondrocytes
