Skeletal System: Bone - Flashcards

Flashcards for Skeletal System

Skeletal System Function

• Provides firm framework

• attachment points for muscles

• allows articulation.

• Protects vital organs

What does the skeleton store?

mineral salts and fats (Ca, P, Na, K)

and red marrow for blood cell production.

Divisions of the skeleton

Axial and appendicular

Parts of the axial skeleton

• skull

• vertebral column

• ribcage (there is a sternum the front)

Appendicular Skeleton

´Pectoral girdle (scapula, collerbone/clavicle, bones of the limbs)

´Upper limbs (the whole of the hand, the whole of the foot)

´Pelvic girdle (pelvis)

Lower limbs

What is the structure of the spine?

is made up of 33 vertebrae divided into five regions.

the intervertebral disc provides cusioning and support for the body, protecting the spinal cord within it.

It also allows for flexibility and movement.

Structure of bone- what does a long bone typically consist of?

Diaphysis: the main portion (shaft)

Epiphysis: enlarged, rounded ends of bone (ends)

What are the epiphyses covered by?

covered by thin layer of cartilage, the articular cartilage)

Flat Bone Function

Protects internal organs

Sesamoid Bone Function

Protects tendons

Irregular Bone Function

Variable nature helps to protect different structures

Short Bone Function

Provide stability and some movement

Upper Limb Bones

Humerus, radius, ulna, carpals, metacarpals, and phalanges.

Lower Limb Bones

Femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges.

Long Bone Structure

Shaft (diaphysis) and ends (epiphyses) covered by articular cartilage.

Diaphysis

Hollow cylinder of compact bone surrounding a cavity with yellow bone marrow.

Epiphyses

Compact bone on the outside, spongy/cancellous bone on the inside containing red bone marrow.

Spongy bone

less dense, porous type of bone tissue found within the interior of bones.

Compact bone

the hard, dense outer layer of bones throughout the human bond, providing strength and protection

Periosteum

Dense, white, fibrous connective tissue covering the outer surface of bone.

Compact Bone microscopic structure

Consists of units called osteons or haversian systems.

What type of structure is bone?

it is a connective tissue

What is matrix?

the cells seperating from each other by large amounts of non-cellular material

What is the function of this matrix?

Inorganic salts (e.g. calcium) are deposited into matrix à increase rigidity and strength

What is an osteon and its structure? What is the other name with which they are referred to?

the units within compact bone

• Haversian system

at the centre of each osteon, there is a central canal

Lamalle

the central canal within the osteon that is surrounded by concentric layers of bony matrix called lamellae.

Lacunae

Small spaces between lamellae that contain osteocytes (bone cells).

Canaliculi

Tiny canals running between lacunae, allowing bone cells to contact adjacent cells and pass materials.
- it always contains at least 1 blood capillary, and sometimes nerves and lymph capillaries.

Spongy (Cancellous) Bone

Irregular arrangement of thin, bony plates called trabeculae.

the osteocytes occupy spaces within the trabeculae

Not arranged in osteons

Matrix in spongy bone

not arranged in concentric layers

nerves, blood vessels pass through irregular spaces in matrix

Osteoblasts

bone cells that form new bones, grow and heal old ones

osteoclasts

bone cells that break down old bone tissue

calcification

refers to the buildup of calcium salts in tissues, which can harden them.

occurs withthe deposits of calcium phosphates in the matrix.

Ossification

• Bones of embryos are largely made of cartilage and are soft.

• these provide a template for ossification

• cartilage undergoes calcification

• chondrocytes die to lack of nutrients

• osteoblasts lay down bone on the disintegrating calcified cartilage template.

label

Epiphyseal Line

The fusing of the diaphysis and epiphysis, indicating the bone can no longer increase in length.

Epiphyseal (Growth) Plate

Site of increase in bone length.

Bone Remodelling

Constant process of bone breakdown by osteoclasts and new bone creation by osteoblasts.