Musculoskeletal System: The Skeleton Flashcards
How many bones does a newborn have?
350
How many bones does an adult human have?
206
What are the functions of the skeleton?
Support, movemement, protection, storage of minerals and blood cell production
What is the support purpose of the skeleton?
Structural and as a framework for the attachment of soft tissues and organs
What is the movement functions of the skeleton?
Attachment of skeletal muscle to bones either side of joints enables movement
What are the protective functions of the skeleton?
Many soft tissues and organs are surrounded by bone for protection
What is the mineral storage function of the skeleton?
Lipids are important for energy reserves and calcium salts are important for maintaining normal concentrations of calcium and phosphate ions in body fluids
What is an epiphysis?
Rounded bit at the end of the bone that contributes to a joint
What is a metaphysis?
Long bones containing the growth plate
What is the medullary cavity?
Hollow part of bone containing bone marrow
What is a synonym for the Epiphysial line?
Cartilage plate
What are the only cell types that are found in healthy cartilage?
Chondrocytes
What do chondrocytes mainly produce?
The cartilaginous matrix (made of collagen)
Does cartilage have a vascular supply?
No
How does cartilage get its blood supply?
From the vasculated tissue around it
What happens in the first stage of endochondral ossification?
Chondrocytes increase in size while the matrix calcifies around them, so they apoptose
What happens in the third stage of endochondral ossification?
Cartilage becomes vasculated and is replaced by trabecular bone.
Fibroblasts differentiate into osteoblasts
What happens in the second stage of endochondral ossification?
Blood vessels grow into the perichondrium and cells differentiate into osteoblasts
What is the periosteum?
The bit around the edge of the cartilage shaft
What is a primary ossification centre?
Where the cartilage matrix is replaced by trabecular bone first
What happens in the fourth stage of endochondral ossification?
Wave of ossification spreads towards the end of long bone
Osteoclasts adsorb bone, leaving a marrow cavity
Bone grows inwards forming the compact bone
What happens in the fifth stage of endochondral ossification?
Capillaries and osteoblasts migrate into the epiphyses and ossification begins
What is the purpose of the epiphyseal growth plate?
Allows interstitial growth in bone
What is an articular centre?
Articulates with cartilage from another bone and prevents bone on bone articulations
How do genetic factors affect bone development?
The overall shape and dimensions of a bone are shaped genetically
How does activity affect bone development?
Bone adapts to meet functional demands
How do nutritional factors affect bone development?
Availability of calcium, phosphate salts, vitamin A, C, D, K and B12
How do hormonal factors affect bone development?
Calcitonin, parathyroid hormone, growth hormone and Estrogen affect calcium levels and bone growth
How do pathological factors affect bone development?
Disease processes like infection, bone tumours and TB
How does age affect bone development?
Loss of calcium and the ability to use it can cause brittle bones which easily fracture
What are the two divisions of the skeleton?
Axial and appendicular
What is the axial skeleton?
Forms central supporting axis of the body
What is the appendicular skeleton?
Bones of the upper and lower limbs, pelvic and pubic girdle
What are the 5 classifications of bone by shape?
long, short, flat, irregular, sesamoid
What are the features of long bones?
Elongated tubular shafts, a central medullary cavity and expanded ends for articulation
What are some examples of long bone?
Femur, humerus and tibia
What are the features of short bones?
Thin outer shell of compact bone with a completely trabecular interior
What are the features of flat bones?
Two shells of compact bone separated by a layer of cancellous bone
What are the features of irregular bones?
Anything that doesn’t fit into any other category
What are the features of sesamoid bones?
Found in tendons
Give some examples of short bones
Carpal bones of the hand and tarsus bones in the foot
Give some examples of flat bones
Frontal and parietal bone, sternum and ribs
Give some examples of irregular bones
Sphenoid bone of the skull
Give some examples of sesamoid bones
Patella
Where is the proximal end of the bone?
Closest to trunk
Where is the neck of a bone?
Narrowing where the shaft meets the epiphysis
Where is the distal end of the bone?
Furthest from the trunk
What is an articular surface of a bone?
Hyaline cartilage that provides wear-resistant lubricated surface to allow two bones to come together
What is a condyle?
Curved articular surface
What is an epicondyle?
Jutting out from the side of an articular condyle
How many bones are in the vertebral column?
32-33
What are the 5 vertebral regions and how many vertebrae are in each?
Cervical (7) Thoracic (12) Lumbar (5) Sacrum (5 fused) Coccyx (3-4 fused vertebrae)
What is a primary vertebral curve?
Present from birth
What is a secondary vertebral curve?
Develops months after birth
Why do the secondary vertebral curves develop?
Produces an s-shaped spine that allows for bipedal walking by ensuring the head is balanced over the bodies centre of gravity
What is scoliosis?
Lateral curvature of the spine
Where does scoliosis happen most commonly?
Thoracic region
What causes scoliosis?
Developmental, in which the body and arch of vertebrae fail to develop on one side
How many bones are in the skull?
22
How many cranial bones are there?
8
How many facial bones are there?
14
How many auditory ossicles are there?
6
What is the function of the mastoid process?
Attachment points for muscles of the head like the sternoclaidomastoid muscle
What is the function of the sternoclaidomastoid muscle?
Turning the head to the side
Where does the mandible articulate with the temporal lobe?
Temoporomandibular point
What is the opening in the occipital bone called and what is its function?
Foramen magnum, where the spinal cord passes
What are cranial sutures?
Fibrous joints connecting the bones of the skull
What does the coronal suture fuse?
Frontal and two parietal bones
What does the lambdoid suture fuse?
Occipital bone with two parietal bones
What does the Sagittal suture fuse?
Two parietal bones
What does the squamous suture fuse?
Parietal bone and squamous part of the temporal bone
What does the parietomastoid suture fuse?
Parietal bone and mastoid process of the temporal bone
What does the occipitomastoid suture fuse?
Occipital bone and mastoid process of the temporal bone
What does the sphenosquamous suture fuse?
Sphenoid bone and squamous part of the temporal bone
What is the pterion?
Junction of sphenoid, temporal, parietal and frontal bone
What is the highest part of the skull called?
Vertex
What is it called where the saggital and coronal sutures meet?
Bregma
What is it called where the saggital and lambdoid sutures meet?
Lambda
What is the asterion?
Junction of the parietal temporal and occipital bone
What shape is the pterion?
H shaped
Where is the weakest part of the skull?
Pterion
When does the anterior Fontanelle close?
Between 13 and 24 months
When does the posterior Fontanelle close?
6-8 weeks
What is the function of a Fontanelle?
Allows for growth of brain and head structures
How many pairs of ribs do you have?
12
Which are the typical ribs?
3-10
Which are the atypical ribs?
1, 2, 11 and 12
What does the pectoral girdle consist of?
Clavicle and scapula
What is the function of the pectoral girdle?
Supports upper limb and connects it to the axial skeleton
How many segments does the upper limb have and what are they called?
3 - arm (proper), forearm and hand
What bone(s) are found in the arm?
Humerus
Where does the humerus articulate?
Glenohumoral joint and elbow joint
What bone(s) are found in the forearm?
Radius and ulna
Where do the radius and ulna articulate?
Elbow joint, wrist joint and the radioulnar joint
What does the radioulnar joint allow for?
Pronation and supination
How many carpal bones do we have and how are they arranged?
8 (two rows of four)
How many metacarpals do we have?
5
How many phalanges do we have and where are they found?
14- fingers
How many phalanges are found in each finger?
3 - proximal, middle and distal portion apart from thumb that only has a distal and middle
What is the function of the pelvic girdle?
Supports lower limb and connects it to the axial skeleton
What is the pelvic girdle made up of?
Hipbones on each side and the sacrum and coccyx
How many segments are found in the lower limb and what are they called?
3- femur, crura and foot
What bone(s) are found in the femur?
Femur and patella
What bone(s) are found in the crural leg segment?
Tibia and fibula
What bone(s) are found in the foot and how many of each?
7 tarsals, 5 metatarsals and 14 phalanges
What are the two main joint classifications?
Functional and structural
What are the functional classifications of a joint?
Synarthrosis, amphiarthrosis, diarthrosis
What is a synarthrosis joint?
Fixed
What is an amphiarthrotic joint?
Slightly moveable
What is an example of an amphiarthrotic joint?
Pubic joint
What is a diarthrotic joint?
Freely moveable
What is an example of a diarthrotic joint?
Elbow or knee
What are the structural classifications of a joint?
Fibrous, cartilaginous and synovial
What is an example of a fibrotic joint?
Skull
What is an example of a cartilaginous joint?
Pubic bones
What is an example of a synovial joint?
Elbow/knee
What does the joint cavity of a synovial joint contain?
Synovial fluid secreted by the synovial membrane
What makes up the articular capsule?
Fibrous capsule and synovial membrane
What are the types of synovial joint?
Hinge, ball and socket, pivot, saddle, gliding, condylar
Give an example of a hinge joint
Elbow/ fingers
Give an example of a ball and socket joint
Shoulder/ hip
Give an example of a pivot joint
Rotation, neck
Give an example of a saddle joint
Thumb - carpalmetacarpal
Give an example of a gliding joint
Carpals
Give an example of a condylar joint
Metacarpal-phalyngeal joints
What causes condylar joints?
Oval-shaped articular surfaces
What causes gliding joints?
Flat surface and a sliding movement