Week 4/5 - Skeleton/MSK Flashcards
Approximately how many bones are in the body
206
Approximately how many bones do babes have?
270 - they fuse together as they age
3 classifications of joints and examples of each
Cartilaginous - inter vertebrate discs
Synovial - knee joint
Fibrous - suture joint in skull
What is a joint
Place where two bones make contact (although not necessarily directly i.e synovial)
What is a fibrous joint
Bones joined by dense fibrous connective tissue
What is a cartilaginous joint
Bones joined by cartilage
What is a synovial joint
A ‘true joint’ where two bones do not directly contact each other, instead they are separated by cartilage
What is the name for joints that do not move at all and give an example
Synarthrosis and an example would be suture joint
What is the name for joints that allow a little movement and what’s an example?
Amphiarthrosis, for example the distal tibiofibular joint
What is the name for joints that allow free movement and give an example
Diarthrosis for example the synovial joint
Name the structures from inside to outside of the synovial joint
Articular cartilage
Synovial membrane
Synovial capsule
Ligament
What is the role of the synovial membrane
It secretes synovial fluid which lubricates the surfaces
What is the role of the ligaments within the context of the synovial joint
It is connective tissue that connects bone to bone and overall strengthens the capsule
What is an example of a continuous joint
Suture - dense fibrous connective tissue
Name 3 shapes of uniaxial joints and give examples of where these are found in the body
Pivot - neck
Plane - acromioclavicular joint
Hinge - elbow
Examples of biaxial joints and where they are found
Condyloid - metacarpophalangeal joint
Saddle - carpometacarpal joint
Examples of multiaxial joints
Ball and socket joint - knee/hip
What is the movement called that involves flexion, abduction, extension and then adduction.
Circumduction
What is the cause of osteoarthritis
Loss of joint space - articular cartilage is worn down, decreasing the space between the epiphysises
Where is osteoarthritis most commonly found
In the weight bearing joints such as knees, hips and hands
Symptoms of osteoarthritis
Stiffness and pain
Reduced mobility
Risk factors for osteoarthritis
Overuse
Prior injury
Rheumatoid arthritis
Obesity
Family history
How can cysts form in bones
When synovial fluid gets into cracks of bone
Name the 2 functional parts of the skeleton and the bones that make up these
Axial skeleton - cranium, neck (hyoid bone and cervical vertebrae), trunk (ribs, sternum, vertebrae and sacrum)
Appendicular skeleton - bones of the limbs including those that form the pectoral and pelvic girdle
Two examples of cartilage
Hyaline cartilage - e.g articular provide a smooth, low friction, gliding surface for free movement. Costal cartilage (connecting ribs to sternum) - allowing flexibility when lungs expand
Elastic/yellow cartilage = found in pinna of ear and larynx
Fibrous - e.g IVD
Is cartilage vascular or avascular
Avascular - gets its nutrients form diffusion
What type of tissue is bone
Connective tissue
Function of bones
Structural support for the body and protection for organs
Allows movement
Storage of salts
Makes new blood cells
What is the fibrous connective tissue called found around the bones
Periosteum
Fibrous connective tissue around cartilage
Perichondrium
Another name for spongy bone
Trabercular
What is the space the diaphysis called
The medullary cavity
Where is bone marrow found in adults
In the medullary cavity and within the spicules of the traberculae, yellow (fat, cartilage and bone producing) or red bone marrow (erythrocytes and platelet producing) is found
3 examples of bone elevations
Ridges (metric ridge)
Tubercules (lesser and greater tubercle of humerus)
Crests (pelvic iliac crest)
5 classifications of bone shapes and examples
Long bones - tubular (humerus)
Short bones - cuboidal (tarsus=ankle + carpus=wrist)
Flat bones - (flat bones of cranium to protect brain)
Irregular bones - other shapes that aren’t flat/short/long
Sesamoid bones - (patella - protect the tendons from damage and are imbedded in tendons)
Where do you find the body of the vertebrae
The anterior, weight bearing side which sandwiches the IVDs
Where do you find the body of the long bone
The shaft of the bone
What is the capitulum
The small, round, articular head e.g capitilum of the humerus
What is a condyle
Rounded, knuckle like articular area often in pairs e.g lateral and medial femoral condoyles
What is a crest
Ridge of the bone e.g iliac crest
What is an epicondyle
Eminences superior or adjacent to a condyle e.g lateral epicondyl of the humerus
What is a facet
Smooth flat area, where a bone articulates with another e.g costal (rib) facet
What is a foramen
Passage through a bone e.g obturator foramen (big hole that allows vessels and nerves to reach the limbs.
What is a fossa
Hollow or depressed area e.g infraspinous of the scapula
What is a groove
An elongationed depression or furrow e.g radial groove of humerus
What is the head
Round articular end of a bone e.g head of humerus
Line/ridge
Linear elevation e.g soleal ridge of tibia
Malleolus
rounded process e.g lateral malleus of the fibula
Neck
Relatively narrow portion proximal to the head
Notch
Indentation at the edge of the bone (e.g greater sciatic notch)
Process
an extension or projection serving a particular purpose, having a characteristic shape, or extending in a particular direction (e.g., articular process, spinous process, or transverse process of a vertebra).
Protuberance
a bulge or projection of bone (e.g., external occipital protuberance).
Shaft
the diaphysis, or body, of a long bone.
Spine
thorn-like process (e.g., the spine of the scapula)
Trochanter
large blunt elevation (e.g., greater trochanter of the femur).
Trochlea
spool-like articular process or process that acts as a pulley (e.g., trochlea of the humerus
Tubercle
small raised eminence (e.g., greater tubercle of the humerus).
Tuberocity
large rounded elevation (e.g., ischial tuberosity).
What is the functional unit of bone
Osteons
70% of bone is made up of
Inorganic e.g calcium and phosphate salts
30% of bone is made up of
Organic material - type 1 collagen
What does collagen I allow in bones
Bending and shock absorbance - if bones were too stiff, they would be very brittle and crumble upon impact
Tensile strength
How well something can withstand stretching or pulling
Compressive strength
How well something can withstand loads
What is the role of osteoblasts
they lay down new bone
What is the role of ostecytes
They break down newly formed bones
What are lamellae
Circles of bone that make up the osteons in compact bone/cortical bone
What structure traps osteocytes
Lamellae
What is another name for spongy bone
Trabercular bone/cancellous
What causes osteomalacia/rickets (in children)
Patients lack vitamin D and have low calcium in their diet. Calcium cannot be stored in medullary cavity as calcium hydroxyapatite. Therefore, when legs bear weight, bones become bowed.
What causes osteogenesis imperfecta
Congenital condition which affects collagen production. As a result bone can not flex in response to bone impact. This makes bones more brittle and more likely to fracture.
Which part of the long bone holds most of the weight
The body/diaphysis
What is the role of the epiphysis
Articular surfaces for joints - mostly trabecular but some of it is cancellous around the edges
What separates the diaphysis and epiphysis
The epiphyseal growth plate
Where is the site of growth
The epiphyseal growth plate
Once bone growth finishes (around end of puberty +/-, what happens to the plate
It ossifies forming the epiphyseal line which later disappears
What is the epiphyseal plate made of
Hyalin cartilage
What is the trophoblastic flat bone that forms the skull
Diploe bone
Outer layer of connective tissue that lines the outside of the bone and function
The periosteum - also acts as a site of attachment for tendons
Inner surfaces of cavities
Endosteum
In what way can bone only grow by and what does this involve
Appositional growth - bone being laid onto a cartilage surface by osteoblasts (differentiated osteoto form osteoid (like bone-not mineralised yet).
In which two ways can cartilage grow by and what does this involve
Growth of cartilage is called chondrification/chondrogenesis.
Appositional growth - cartilage being laid upon more cartilage by chondroblasts
Interstitial growth - chondroblasts differentiate into chondrocytes which make up cell ‘nests’ in the lacunae
What produces osteocytes
Osteoblasts
What produces chondrocytes
Chondroblasts
What type of collagen makes up cartilage
40% of cartilage is made up by collagen II
As ossification occurs, what happens to the epiphysis and the diaphysis
They get closer together and fuse together later in development, forming the epiphyseal line which eventually disappears
Why are osteoblasts important in response to strain
In response to micro fractures, they can send signals that initiate bone formation or reabsorption of minerals (calcium or phosphate minerals)
What percentage of compact bone/trabecular bone is replaced every year
5%
What percentage of soft/cancellous bone is replaced every year
25%
How many bones in the skull
22
How many bones in the vertebral column
Around 33
How many bones in the ribs
12
How many bones make up the face (viserocranium)
14 bones
How many bones make up the neurocranium (surrounding the brain)
8
Vertebral column names, basic function and how many vertebrae in each
Cervical - movement of neck - 7
Thoracic - articulate with ribs - 12
Lumbar - 5
Sacrum - articulate with hips - 5 fused
Coccyx - 4 fused?
What bones make up the pectoral girdle
Scapula and clavicle
What is the only bone connecting the upper limbs to axial skeleton
Clavicle, therefore great range of movement
Which bones make up the pelvic girdle
The innominates - the only bones that are fused to either side of the sacrum (think vertebral column)
Ilium
Ischium
Pubis
How many bones make up the carpals
8
How many bones make up the hand
metacarpals = 5
phalanges = 14
Which forearm bone is most lateral to the sternum
Radius
Which leg bone is most lateral to the sternum
Fibula
How many bones make up the ankle (tarsal)
7
How many bones make up the metatarsals
5
How many bones make up the phalanges
14
At what level is the sternal angle
Between level C4+5, in line with associated IVD
Or the second rib
What joint marks the sternal angle
manubriosternal joint
Which structures of the heart does the sternal angle cut through
Pulmonary valve and aortic valve
What does the sternal angle form the boundary of
Mediastinum - a membranous partition between 2 body cavities
5 zones of epiphyseal growth plate
Resting - resting/reserve cartilage cells called chondrocytes which replicate slowly.
Proliferation - zone of proliferation where the cells divide more rapidly and line up along axis of the bone.
Hypertrophy - chondrocytes mature and expand In size (zone of hypertrophy).
Calcification - The expanded cells become calcified.
Ossification - blood vessels and bone cells invade the calcified cartilage and begin to replace the structure with bone.
What is the difference between primary and secondary ossification centre
Primary - formation of diaphysis- first place for ossification to happen (in long bone)
Secondary - epiphysis formation (in long bone)
What is the purpose of fontanelles
Allow flexibility for brain development and during birth!
What are 3 factors that can affect timing of ossification
sex
race
stress
nutrition
What can bone development (skeletal age) be used to determine
Age of immigrants
Age fraud
What is osteoporosis
When bone is broken down quicker than it is replaced, resulting in decreased bone density. More likely to fracture
Can cause kyphosis (bending of spine)
What are osteophytes
Bony spurs found on spine as a result of osteoarthritis
What are ethesophytes
Calcification of ligament/muscle attachment point
What is periostitis
Inflammation of the periosteum (outer layer of bone) sometimes causing extra bone to be laid down, loss of nicely organised lamellae.
Caused by trauma or infection
3 types of muscle and give basic description
Skeletal - voluntary movement, form most large muscles, can tire
Cardiac - involuntary movement, form the walls of the heart, don’t tire
Smooth - involuntary, viscera (internal organs in main body cavities, blood vessels, Iris, don’t tire
What are skeletal muscle fibres grouped into
Muscle fascicles
What is a skeletal muscular head/belly
Contractile part of muscle
How are skeletal muscles usually linked to bone/other structures
A tendon or a aponeurosis (flat sheet)
What does the range of skeletal movement depend on
The length of of muscle
What does the strength of muscle depend on
The number of fibres
Name of triangular looking muscle
Trapezius
Name back muscles and show their location on a diagram
Trapezius (superficial)
Infraspinatus (superficial)
Deltoid (superficial)
Teres major (superficial)
Teres minor (superficial)
Triceps brachii (superficial)
Latissimus dorsi (superficial)
Rhomboids minor and major (deep)
Levator scapulae (deep)
What are the origin attachment points of the trapezius muscle
C7-T12 spinous processes
Superior nuchal line
Nuchal attachments
What is the insertion attachment points of the trapezius when descending
lateral third of clavicle
What is the insertion attachment point of the trapezius when horizontal
Acriom of the scapula
What is the insertion attachment point of the trapezius when ascending
Spine of scapula
What is the action of the trapezius on shoulder girdle when descending
keeps the shoulder girdle up (think when carrying heavy shopping bags)
Action of trapezius on shoulder girdle when horizontal/ascending
depresses and pulls the scapula medially
Action of trapezius on head/neck when an arm descends with fixed shoulder
neck goes right/left
Action of trapezius on vertebral column
Flattens the thoracic kyphosis (curvature)
Which nerve supplies the trapezius muscle
cranial nerve xi accessory
Origin attachment points of latissimus dorsi
Spinous processes T7-T12
Dorsal surface of sacrum
Dorsal 1/3 of the iliac crest
Thoraco-lumbar aponeurosis
10-12th ribs
Inferior angle of the scapula
Insertion points of latissimus dorsi
Humerus - floor of inter-tubercular sulcus
