Bone Flashcards
Skeletomuscular system - Bones
How many bones do adults have?
206
Skeletomuscular system - Bones
How many muscles do adults have?
640 named ones
Skeletomuscular system - Bones
How many joints does a human have?
360
Skeletomuscular system - Bones
How many tendons does a human have?
4000
Skeletomuscular system - Bones
What does tendons connect?
Muscles to bones
Skeletomuscular system - Bones
How many ligaments do humans have?
900
Skeletomuscular system - Bones
What do ligaments connect?
Bone to bone
Skeletomuscular system - Bones
Anotomical position
Stand erect, feet parallel and eyes forward
Palms facing forward

Skeletomuscular system - Bones
Which position is used as the standard reference point?
Anotomical position

Skeletomuscular system - Bones
Fundamental position
Similar to anatomical position
Arms more relaxed
Palms facing forward

Skeletomuscular system - Bones
Two divisions of the skeleton
Axial skeleton
Appendicular skeleton
Skeletomuscular system - Bones
How many bones in the axial skeleton?
80
Skeletomuscular system - Bones
What is the axial skeleton made up of?
Skull
Hypoid bone
Vertebral column
Thorax cage
Skeletomuscular system - Bones
Hyoid bone
Anchors tongue and muscles associated with swallowing
Skeletomuscular system - Bones
What does the axial skeleton do?
Supports and protects organs of the head, neck and trunk
Skeletomuscular system - Bones
How many bones in the appendicular skeleton?
126
Skeletomuscular system - Bones
Which type of bones are part of the appendicular skeleton?
Bones of limbs and bones that anchor limbs to the axial skeleton
Skeletomuscular system - Bones
Which bones are part of the pendicular skeleton?
Pectorial girdle
Upper limbs
Pelvic girdle
Lower limbs

Skeletomuscular system - Bones
Articulation
Where joints meet, connect and are formed
Skeletomuscular system - Bones
Functions of the skeletal system
Support the body
Storage of minerals and lipids
Blood cell production
Protection of soft organs
Movement due to attached skeletal muscles
Skeletomuscular system - Bones
Types of bone
Long
Short
Flat
Irregular
Skeletomuscular system - Bones
What are the two basic type of bone tissue?
Compact
Spongy
Skeletomuscular system - Bones
Spongy bone
Small needle-like pieces of bone
Has lots of open spaces for blood supply
Skeletomuscular system - Bones
Osteons
The basic functional units of mature compact bone
Skeletomuscular system - Bones
What makes up a bone?
Hydroxypatite
Calcium salts
Collagen fibres
Cells
Skeletomuscular system - Bones
What makes up 2/3 of a bones weight?
Calcium phosphate
Skeletomuscular system - Bones
What makes up 1/3 of a bones weight?
Collagen fibres
Skeletomuscular system - Bones
What accounts for about 2% of a bones weight?
Cells
Skeletomuscular system - Bones
Hysroxyapatite
Hard and brittle part of bones
Made up of calcium phosphate and calcium hydroxide
Skeletomuscular system - Bones
Collagen fibres
Very strong
Easily tolerates twisting and bending
Provides organic framework of bone for hydroxypatite crystals to form on
Skeletomuscular system - Bones
What are cells are present in the bones?
Osteocytes
Osteoblasts
Osteoclasts
Skeletomuscular system - Bones
Osteocytes
Mature bone cells
Found deep within the bone matrix
Skeletomuscular system - Bones
Osteoblasts
Bone forming cells
Fills the cavities left by osteoclasts
Skeletomuscular system - Bones
Osteoclasts
Bone destroying cells
Remove old bone
Dissolve minerals
Skeletomuscular system - Bones
Which are the bone destroying cells?
Osteclasts
Skeletomuscular system - Bones
What is the skeleton primarily made of in embryos?
Hyaline cartilage
Skeletomuscular system - Bones
Where does cartilage remain in the adult body?
Bridge of the nose
Parts of ribs
Joints
Skeletomuscular system - Bones
What changes to the embryos skelaton as it develops?
Most of the cartilage is replaced by bone
Skeletomuscular system - Bones
What are the two growth mechanisms in cartilage
Intersitial growth
Appostional growth
Skeletomuscular system - Bones
Describe the matrix of the cartilage
Firm gel containing polysaccharide derivatives called chondroitin sulfates
Skeletomuscular system - Bones
What cells are present in cartilage?
Chondrocytes
Skeletomuscular system - Bones
Where would you find the chondrocyte cells in cartilage?
In small chambers called lacunae
Skeletomuscular system - Bones
Interstitial growth
Cell division
Enlarges the cartilage from within
Skeletomuscular system - Bones
Appositional growth
Cells of the inner layer of the perichondrium undergo repeated cycles of division
New layers of cartilage are added to the surface
Skeletomuscular system - Bones
Three major types of cartilage
Hyaline
Elastic
Fibrocartilage
Skeletomuscular system - Bones
What are the issues with cartilage
No blood supply
No nerve supply
Difficult to repair
Skeletomuscular system - Bones
Difference between young and adult long bone structure
Growth plate present in children and adolescents
Replaced by an apihyseal line in adults
Skeletomuscular system - Bones
Epiphysial plate
Growth plate
Hyaline cartilage plate in the metaphysis at each end of a long bone
Skeletomuscular system - Bones
Ossification
Calcium salts are deposited
Skeletomuscular system - Bones
Endochrondral
Bone replaces existing cartilage
Skeletomuscular system - Bones
Intramembranous ossification
Bone develops directly from mesenchyme or fibrous connective tissue
Normally occurs in the deeper layers of the dermis
Also an essential process during the natural healing of bone fracures
Skeletomuscular system - Bones
How many bones in the skull?
22
Skeletomuscular system - Bones
Bones of the cranium
8 sutured bones
Skeletomuscular system - Bones
Facial bones
13 sutured bones
1 mandible
Skeletomuscular system - Bones
What is a fontanel?
Soft membranous gaps between the imcompletely formed cranial bones in an infant
Both anterior and posterior

Skeletomuscular system - Bones
When does the anterior fontanel close up?
At 9-18 months
Skeletomuscular system - Bones
When does the posterior fontanel close up?
Within 2-3 months
Skeletomuscular system - Bones
Types of head injuries
Closed head injuries
Open/penatrating wounds
Skeletomuscular system - Bones
Paransal sinuses
Hollow portions of bones surrounding the nasal cavity

Skeletomuscular system - Bones
The hyoid bone
Serves as a moveable base for the tongue and other muscle attachments
Aids in tongue movement and swallowing
Skeletomuscular system - Bones
What is the only bone that does not articulate with another bone?
The Hyoid bone (one in the mouth)

Skeletomuscular system - Bones
Fibrodysplasia Ossificans Progressiva (FOP)
Causes fibrous tissue to be ossified
Causes loss of mobility
Skeletomuscular system - Bones
What is the cause of Fibrodysplasia Ossificans Progressiva?
A mutation in ACVR1 gene on chromosome 4
Skeletomuscular system - Bones
Melorheostosis
Irregular hyperstosis
Causes abnormal bone shape and limb deformity
Skeletomuscular system - Bones
Oesteoporosis
Condition where bones have lost minerals
Bones become brittle and more susceptible to fracutres
Skeletomuscular system - Bones
What bones can be affected by osterporosis?
Any bone in the body
Skeletomuscular system - Bones
Risk factors for ossteoporosis
Increased age
Ethnic origin
Low BMI
Family history
Lifestyle choices
Skeletomuscular system - Bones
Are men or women more likely to suffer from osteoporosis?
Women
Skeletomuscular system - Bones
Oestrogen effect on osteoporosis
- Oestrogen deficiency
- Low calcitrol
- Intestinal malabsorption of Ca2+
- Calcium deficiency
- Increased parathyroid hormone
- Osteoclasts release Ca2+ from bone
Skeletomuscular system - Bones
When does bone denisty peak?
Around 30 years of age
Skeletomuscular system - Bones
Scan used to tests bone density
Dual energy X-ray absorptiometry scan
Skeletomuscular system - Bones
Rickets
Softening and weakening of bones in children
Usually cause by an extreme and prolonged vitamin D deficiency
Skeletomuscular system - Bones
Myeloma
Form of cancer
Abnormal cells collect in the bone marrow and form tumours
Can happen in one or more bones