chapter 8 - purely skeletal system Flashcards
list the functions of the skeleton
- provides a scaffold to support the weight of the rest of the body
- facilitates movement by being points of attachment for muscles
- protection of vital internal organs
- produces RBC’s
- stores and releases minerals and fats
how many bones make up the adult human skeleton?
206
what are the two sections that bones of the skeleton are divided into?
the axial skeleton and the appendicular skeleton.
what is the axial skeleton?
bones that lie around the central axis of the body
what is the appendicular skeleton?
bones of the upper and lower limbs
what are the 5 different types of bones?
- long bone
- short bone
- irregular bone
- flat bone
- sesamoid bone
long bone
supports weight and allows movement
eg. femur
short bones
provide stability and some movement
eg. intermediate cuneiform, lateral cuneiform, medial cuneiform
irregular bone
variable nature helps to protect different structures
eg. vertebrae
flat bone
protects internal organs
eg. sternum
sesamoid bone
protects tendons
eg. patella
what are the three distinct parts of long bones
- diaphysis - shaft making up the main portion of the bone - cavity acts as a fat storage sight and is called the yellow bone marrow. (WBC’s are produced here)
- epiphyses - enlarged ends of the bone, covered in a thin layer of cartilage. compact bone on outside but spongy/ cancellous bone on the inside. (RBC’s are produced here)
- periosteum - dense, white, fibrous outer covering of the bone.
microscopic structure of bone
- bone is classified as a connective tissue (cells separated from each other by large amounts of non-cellular material called matrix)
- in bone, inorganic salts of calcium and phosphate are deposited in the matrix, increasing its rigidity and strength.
microscopic structure of compact bone
the consist of units called osteons, which run parallel to the long axis of the bone, giving the bone maximum strength.
description: consist of osteons with concentric layers of lamellae.
microscopic structure of spongy bone
also called cancellous bone
it consists of thin, bony, irregular plates called trabeculae
- bone cells occupy spaces in the trabeculae, and nerves and blood vessels pass through irregular spaces in the matrix.
structure of cartilage
it is a connective tissue
it contains numerous fibres made up of a protein called collagen. these fibres are embedded in a firm matrix of a protein-carbohydrate complex called chondrin.
what does chondrin do for the bone?
chondrin allows cartilage to function as a structure of support.
what does collagen do for the bone?
the presence of collagen fibres gives the cartilage a certain degree of flexibility.
explain the process of cells maturing, becoming chondrocytes
cartilage has a firm matrix in which collagen fibres are embedded. within the matrix are spaces that contain cartilage cells called chondroblasts.
- these cells produce matrix and gradually become surrounded until they are surrounded in small spaces called lacunae.
- once this has occurred, the cells are considered to be mature and called chondrocytes