Question

mogus or a typical long bone below 4. How are spongy and compact bone different & similar in their structure and organization? • What type of bone tissue are trabeculae and osteons associated with? Where, specifically, do you find central canals, circumferential lamellae, perforating canals, periosteum, concentric lamellae, osteocytes, canaliculi, lacunae, and endosteum? How are the collagen fibers oriented in osteons? i. What is the benefit of the pattern of organization? Due to their structural differences how do the different types of bone handle physical/mechanica stress?

Answer 1

4). Spongy vs Compact Bones

Spongy Bones	Compact Bones
Spongy Bones are also called cancellous bones	Compact bones are also called cortical bones
They light, spongy and soft in nature	They are heavy, tough and compact in nature
They are made up of trabeculae	They are made up of osteons
They fill the inner layer of most bones	They fill the outer layer of most bones
Bone-marrow cavity absent	Bone-marrow cavity present in the centre
Bone marrow produces red corpuscles and white granular corpuscles	Bone marrow stores fat
It forms the ends or epiphyses of long bones	It forms the shaft or diaphysis of long bones

Compact bones are the present in the outer layer of long bones, while spongy bones are present in the middle of the long bones.

**Similarities Between Compact and Spongy Bone:-

• Compact bone and spongy bones are the two types of bones in animals.
• Both compact and spongy bones are made up of osseous tissue, which is a type of connective tissue that makes the bone.
• Both compact and spongy bones are involved in the movement of the body.
• Both compact bone and spongy bones contain calcium.

1st part:- Trabeculae is associated with Spongy bone. Osteons are associated with Compact bone.

2nd part- In the Compact bone, we can find central canals, circumferential lamellae, perforating canals, periosteum, concentric lamellae, osteocytes, canaliculi, lacunae, endosteum.

3rd part:-Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surround a central canal, the haversian canal. Each haversian canal is surrounded by varying number (5-20) of concentrically arranged lamellae of bone matrix. Near the surface of the compact bone, the lamellae are arranged parallel to the surface; these are called circumferential lamellae. Some of the osteoblasts develop into osteocytes, each living within its own small space, or lacuna. Osteocytes make contact with the cytoplasmic processes of their counterparts via a network of small transverse canals, or canaliculi. This network facilitates the exchange of nutrients and metabolic waste. Collagen fibers in a particular lamella run parallel to each other, but the orientation of collagen fibers within other lamellae is oblique. The collagen fiber density is lowest at the seams between lamellae, accounting for the distinctive microscopic appearance of a transverse section of osteons.

4th part:-Compact bones are heavy, extremely tough, and are formed or stacked in layers. Since it forms the superficial layer of the bones, it account for more than 75-80 per cent of the weight of the entire skeletal system of a human.

Spongy bones, on the other hand, are lighter than compact bones. They fill the inner layer of most bones such as the vertebrae. The main function of it is to save materials, provide movement, give protection to important body organs, and most of all to give support to the entire structure of the body