Question

Articular Cartilage

Articular Cartilage

Canaliculi
Canaliculi

Central (Haversian) Canals
Central (Haversian) Canals

Compact bone
Compact bone

Diaphysis
Diaphysis

Distal Epiphysis
Distal Epiphysis

Endosteum
Endosteum

Epiphyseal Line
Epiphyseal Line

Epiphyseal Plate
Epiphyseal Plate

Lacunae
Lacunae

Lamellae
Lamellae

Medullary Cavity
Medullary Cavity

Osteocyte
Osteocyte

Osteon (Haversian) System
Osteon (Haversian) System

Perforating (Volkmann’s) Canals
Perforating (Volkmann’s) Canals

Perforating (Sharpey’s) Fibers
Perforating (Sharpey’s) Fibers

Periosteum
Periosteum

Proximal Epiphysis
Proximal Epiphysis

Red Marrow
Red Marrow

Spongy bone
Spongy bone

Yellow Marrow

Answer 1

Number 2 is the Diaphysis.

What is the Diaphysis?

The diaphysis constitutes the primary cylindrical section of a long bone, serving as its central shaft or body. Long bones in structures like the arms, legs, fingers, and toes feature the diaphysis, typically composed of dense cortical bone tissue surrounding a central medullary cavity.

Within this diaphyseal medullary cavity lies bone marrow, responsible for both blood cell production and fat storage.

See the attached image for more clarity on the diaphysis