Bones and joints Flashcards
How many bones are in the human body?
206
Why do newborns have more than 206 bones?
some of the bones are yet to fuse together
Which have more bones: hand and wrist or foot and ankle?
Hand and wrist (27) have more bones than the foot and ankle (26)
What are the 2 types of skeleton?
axial skeleton and appendicular skeleton
What is the axial skeleton made up of?
cranium, vertebrae, ribs
Function of the axial skeleton?
allows the attachment of limbs and protects the CNS and thorax
Function of articular cartilage
lines ends of bones in joints to prevent friction
Function of costal cartilage
connects ribs to sternum
What is the shaft of a long bone known as?
diaphysis
What are the ends of a long bone known as?
epiphysis
What are the two types of bone?
compact/cortical and cancellous/trabecular bone
Which direction are the fibres orientated in cancellous/trabecular bone?
fibres are orientated in the direction of stress
What are growth plates known as?
epiphyseal plates
Where are epiphyseal plates located?
metaphysis (region between the epiphysis and diaphysis)
When do epiphyseal plates close over?
at end of puberty / late teens
What could be mistaken as a fracture in radiographs of long bones?
epiphyseal plates that are not sealed in children
What are the 3 types of joints?
synovial joints, fibrous joints, cartilaginous joints
Why type of joint allows extensive movement?
synovial joint
Components of synovial joints
articular (hyaline) cartilage, marginal (fibro) cartilage, synovial fluid in joint capsule, ligaments, tendons, muscle
Function of ligaments
passive stabilisers that connect bone-to-bone
Function of tendons
active stabilisers that provide musculo tendinous support
Name of the outer layer of bone
periosteum
What are the 2 components that make up the articular capsule in synovial joints?
outer layer made of a fibrous capsule while inner layer made of synovial membrane
What is the name of the cavity within the articular capsule?
joint/synovial cavity
What does the joint/synovial cavity contain?
few ml of synovial fluid
2 types of fibrous joints
sutures of the skull and syndesmoses
What are fibrous joints held together by?
dense connective tissue
What are the areas of a newborn’s cranium where the sutures are not sealed completely?
anterior and posterior fontanelle
When does the anterior fontanelle close?
9-18 months
When does the posterior fontanelle close?
1-2 months (or already closed at birth)
What is a syndesmosis?
a fibrous joint between 2 parallel bones linked by ligaments and a strong membrane
Features of syndesmosis
there is a greater distance between articular surfaces and more dense connective tissue
Example of syndesmosis
distal tibia and fibula
What are the 2 types of cartilaginous joints?
synchondroses (primary cartilaginous joint) and symphysis (secondary cartilaginous joint)
What is synchondroses?
A type of cartilaginous joint where bones are connected by hyaline cartilage. They are immovable (synarthrosis)
What are immovable joints called?
synarthrosis
Examples of synchondroses
joining of ilium, pubis and ischium, the epiphyseal plate (temporary synchondroses). first sternocostal joint (permanent synchondroses)
What is symphysis?
a secondary cartilaginous joint where the bone ends are covered in hyaline cartilage and there is a fibrocartilage disk in between.
Examples of symphysis
intervertebral disks, pelvis, sternum, ribs
What are the two parts that make up the cranium (skull)?
Neurocranium and viscerocranium
What does the neurocranium cover?
brain and meninges
2 parts that make up the neurocranium
calvaria (roof) and cranial base (floor)
How many bones make up the neurocranium?
8 bones - frontal, ethmoid, sphenoid, occipital, parietal (2), temporal (2)
What does the viscerocranium form?
facial skeleton
How many bones make up the viscerocranium?
14
Term used to describe bones with air inside
pneumatised
Which bones of the cranium are pneumatised?
frontal, temporal, sphenoid, ethmoid, maxillary bones
Which bones have are pneumatised in the form of paranasal sinuses?
frontal, sphenoid, ethmoid, maxillary bones (not temporal)
How are the temporal bones pneumatised?
by mastoid air cells
What is the weakest part of the skull?
pterion
Why is the pterion the weakest point of the skull?
it is where the frontal, parietal, temporal and sphenoid bones all meet
Why can trauma at the pterion be dangerous?
can lead to the rupture of the middle meningeal artery (and vein) which can cause an extra-dural haemorrhage
What is a potential route for infections from the skin to get deeper from the parietal bone?
parietal foramen - lets in small blood vessels from superficial to deep
What disease can result if infections enter via the parietal foramen?
meningitis
How many vertebrae make up the vertebral column?
33 - 7C, 12T, 5L, 5S, 4C
How many vertebrae in the cervical region?
7 (C1-C7)
How many vertebrae in the thoracic region?
12 (T1-T12) - for each of the 12 ribs
How many vertebrae in the lumbar region?
5 (L1-L5)
How many vertebrae in the sacrum?
5 fused vertebrae
How many vertebrae in the coccyx?
4 fused vertebrae
Features of a typical vertebra
vertebral body and a vertebral arch which together form a vertebral foramen
Features of a typical vertebral arch
spinous process centred posteriorly, transverse processes extending laterally, pedicles connecting the vertebral body to the transverse processes, lamina connecting transverse and spinous processes, and superior and inferior articular processes between the lamina and pedicle.
What is the spinal cord enclosed by?
vertebral canal - formed by the all vertebral foramens lined up
Which aspect of the vertebral arch articulates with ribs in thoracic vertebrae?
transverse processes
At which vertebra does the first rib extend from?
T1
Which 2 vertebrae do not have the typical structure?
C1 (atlas) and C2 (axis)
What features are unique about C1/atlas?
has no body, the transverse processes have a transverse foramen
Function of the transverse foramen
location where the vertebral artery passes through, ensuring it is well protected
Function of vertebral artery
provides 20% of the brain’s blood supply
What is unique about the structure of C2/axis?
Has a much more prominent body with an extension called the dens
How does the structure of C1 and C2 allow for the movement of the head?
the body/dens of C2 passes upwards through C1 which allows rotational movement
What is the superior limit of the thorax?
T1 and attachment of first rib to manubrium of sternum
What is the inferior limit of the thorax?
diaphragm
Clinical relevance of the Jugular notch
feeling for trachea, deviations that could indicate pathology in lungs (e.g. collapse, fluid)
What is the pectoral girdle?
the bones that connect the arms (appendicular skeleton) to the axial skeleton
Which bones make up the pectoral girdle?
clavicle and scapula
Where is the sternal angle?
Where the second rib joins the sternum, between the manubrium and the body of the sternum
How can the sternal angle be used clinically?
to count ribs inferiorly and laterally for chest drain insertion (for patients with pneumothorax or effusion)
Name of the joint between the costal cartilage and rib
costochondral joint
Which ribs are true ribs?
ribs 1-7
Why are ribs 1-7 regarded as true ribs?
their costal cartilage links directly with sternum
Which ribs are false ribs?
8-10
Why are ribs 8-10 regarded as false ribs?
their costal cartilages are attached to the cartilage of the superior rib
Which ribs are the floating ribs?
ribs 11 and 12
Why are ribs 11 and 12 known as false ribs?
they are short ribs that don’t attach to the sternum. Instead their costal cartilages terminate within the musculature of the lateral abdominal wall.
What is the space between the ribs called?
intercostal space
What is the name of the fibrocartilage between the vertebrae?
intervertebral disks
Function of intervertebral disks
cushion and protect vertebrae
What are the 3 parts of the sternum?
manubrium, body, xiphoid process
How is the sternum connected to the pectoral girdle?
Sterno-clavicular joint
How are the upper limbs connected to the pectoral girdle?
acromio-clavicular joint
Which vertebrae do not have intervertebral discs?
the very top cervical vertebrae
In which direction does the vertebral body increase in size?
Vertebral body increases in size as you go down (they carry more weight)
Which 3 bones make up the hip?
iliac/ilium, pubic, ischium
What are the 3 components of the pubis?
pubic body, superior pubic ramus (forms part of acetabulum), inferior pubic ramus (extends towards ischium)
Name of the joint that connects the pubis
symphysis pubis (cartilaginous joint)
Name of the bone of the upper arm
humerus
Name of the socket in the scapula that forms part of shoulder joint
glenoid fossa
Why are shoulder dislocations more common than hip dislocations?
glenoid fossa is very shallow (compared to acetabulum)
What feature attempts to increase the depth/volume of the glenoid fossa?
labrum (extra cartilage)
Name of the 2 bony projections from the scapula
coracoid and acromion (forms acromio-clavicular joint)
What are the 2 bones of the lower arm?
radius and ulna
Which bone of the lower arm is on the thumb side?
radius
Which bone of the lower arm is on the pinky side?
ulna
Name of the 2 rotatory movements of the forearm / radius and ulna?
pronation and supination
Name of rotation of palm upwards
supination
Name of rotation of palm downwards
pronation
What is the olecranon?
the prominence on the ulna that helps joining to humerus
What feature of the radius helps linkage to the elbow joint?
radial head
Which nerve is responsible for the tingling sensation when hitting the funny bone (olecranon)?
ulnar nerve
How many bones in the hand and wrist?
27 (8 carpal, 5 metacarpals, 14 phalanges)
Name of the bones of the wrist
carpal bones
How many carpal bones are there in each wrist?
8
Which bones extend from the carpal bones?
metacarpals
How many metacarpals are there?
5
How many phalanges are there? (same name and number for feet and hands)
14 (2 in thumb, 3 in other digits)
What is the singular for phalanges?
phalanx
Which is the biggest and strongest bone in the body?
pelvis (can take up to 20 times body weight)
Name of the bone in thigh
femur
How does the femur help humans be bipedal (stand on 2 lower limbs)?
femur directs weight inwards (hip sticks out) which centres gravity, allowing for an upright position
Name of the socket of the hip joint
acetabulum
Which bones form the acetabulum?
formed by the fusion of the hip bones - ilium, pubis, ischium
What forms the ball in the hip joint?
femoral head
Where does a ‘hip’ fracture typically occur?
femoral neck (not hip bones)
Name of projections of the femur that allows for muscle attachment
greater and lesser tuberosity/trochanter
When would fracture of the actual hip bones occur?
high impact incidences e.g. road traffic accidents
Which bones form the knee joint?
patella, femur (condyles), tibia
Name of the rounded ends of the distal femur
medial and lateral femoral condyles
Name of the bones in the lower leg
tibia (medial) and fibula (lateral)
Name given to a bone embedded in a tendon
sesamoid bone
Example of a sesamoid bone
patella (embedded in tendon of quadriceps)
Name of the 2 projection in the ankle
medial malleolus and lateral malleolus
Which bone gives rise to the medial malleolus projection?
tibia
Which bone gives rise to the lateral malleolus projection?
fibula
Which bone forms the heel?
calcaneus
How many bones in the ankle and foot?
26 (7 tarsal, 5 metatarsal, 14 phalanges)
Name the bones of the ankle and foot
tarsal (inc talus and calcaneus bones), metatarsals and phalanges
