The Skeletal System Flashcards
(95 cards)
1
Q
connective tissue
A
connective tissue in adults comes in many forms. they link muscles and bones together to create a system capable of producing movement.
variety of them including - fat, collagen, fibrous tissue,, cartilage
2
Q
fat (connective tissue)
A
packing and insulating substance capable of acting as shock absorber - protects bones and internal organs
fat is stored for this purpose under the heel, in the buttocks and palm of the hand (subcutaneous)
subcutaneous fat is divided into compartments by fibrous tissue that stiffens in response to the protective demands placed upon it
3
Q
Collagen (connective tissue)
A
primary structural protein found in connective tissue and plays integral role in binding tissues together
about 25-35% of the body’s protein tissue is made from collagen which is arranged in 2 diff forms:
- irregular = fibres have a random arrangement and do not have parallel bundles. this is most commonly found in the skin
- regular = fibres are arranged in parallel bundles and can be further divided into white and yellow fibrous tissue
4
Q
Fibrous Tissue (connective tissue)
A
found throughout body, particularly in the dermis of the skin, muscles, tendons and ligaments. there are two types:
- white fibrous tissue = has the most regular collagen fibres and is incredibly dense. this density provides considerable strength without compromising its flexibility and elasticity. white fibrous tissue forms ligaments, tendons and the perimysium which is the protective membrane surrounding clusters of muscle fibres
- regular = this has a predominance of elastic fibres which allows it to perform the highly specialised function of deforming and reforming. yellow fibrous tissue is primarily found in the walls of the arteries and a small number of spinal ligaments that assist the spinal muscles in maintaining an erect posture, particularly the ligamentum flavum
5
Q
cartilage
A
supplementary to bone and is found where rigidity and strength are required. it is not as strong as bone tho. 2 types:
- articular cartilage
- fibrocartilage
6
Q
bone
A
bone is hard tissue with great deal of resistance
interwoven mix of fibrous connective tissue that is saturated with mineral salts.
its connective tissue provides bone with toughness and elasticity, whilst mineral salts provide hardness and rigidity
the mineral component of bones is a readily available store of calcium that is continuously exchanged with bodily fluids
7
Q
compact bone
A
sometimes called cortical bone
toughest of 2 bone forms
laden with minerals, bone cells, blood and lymph
accounts of approx 80% of skeletal mass
found most prominently along diaphysis of long bones
protected by dense layer of fibrous tissue known as periosteum
means can withstand high levels of stress during movement and impact
8
Q
cancellous bone
A
sometimes called spongy or trabecular bone
found usually towards ends of long bones
also found in core of vertebra
inside is a complex arrangement of boney tissue called trabeculae
the trabeculae arrangement of the cancellous bone resembles that of lattice, running in many different directions to maximise its strength, whilst enabling it to stay light enough to move
multi-directional arrangement of the cancellous bone is designed to resist compressive, tensile and shearing forces.
9
Q
bone marrow
A
primarily responsible for producing red and white blood cells
can be found in both red and yellow form
red is most prevalent in infants and towards puberty
much of red is gradually replaced with yellow fat marrow
yellow primarily found in medulla while red stored in cancellous bone
10
Q
regulation of bone development
A
the hormones involved in the regulation of bone density are:
testosterone, oestrogen, calcitonin, parathyroid hormone
when these hormones are low, the bones ability to retain calcium is diminished and risk of osteoporosis is increased
11
Q
osteoporosis risk factors
A
age bone structure (petite frame) family history specific diseases pregnancy (hormonal changes) history of fractures as adult smoking underweight (bodyfat <17%) white or Asian female sedentary lifestyle early menopause history of eating disorders high protein intake, especially animal protein excessive sodium intake alcohol abuse use of anabolic steroids high caffeine intake vitamin d deficiency
12
Q
osteoarthritis risk factors
A
age family history women repetitive loading activities/posture repetitive loading from sporting actions smoking other medical conditions
13
Q
5 primary types of bone
A
long bones short bones flat bones irregular bones sesamoid bones
14
Q
long bones
A
act as levers - large range of movement required locations
recognised by distinct diaphysis and prominent epiphysis
eg femur and humerus
15
Q
short bones
A
fine and precise movement areas
less strength than long bones
eg carpals and tarsals
16
Q
flat bones
A
protect vital organs
attachment sites for skeletal muscles
eg cranium, pelvis, scapula and ribs
17
Q
irregular bones
A
located in spine and face
protect vital organs and surrounding structures
gives unique facial structures
18
Q
sesamoid bones
A
resemble sesame seeds
usually embedded in a tendon
eg patella, first metacarpal, first metatarsal
19
Q
appendicular skeleton
A
all bones in arms and legs, scapula and pelvis and bones in the extremity
two primary components = pectoral (shoulder) girdle and pelvic girdle
20
Q
axial skeleton
A
primary supporting structure of body
spine, ribs, sternum, cranium and hyoid bone
more rigid than appendicular
21
Q
3 classifications of joints
A
fused, fibrous, immoveable
slight moveable, cartilaginous
freely moveable, synovial
22
Q
fused, fibrous immoveable joints
A
no movement permitted - articulating bones are fused together by fibrous ligaments
protect vital areas of body
eg. fusion of flat bones in skull, joining of irregular bones in sacrum and coccyx.
23
Q
cartilaginous - slightly moveable joints
A
bones are attached by fibrocartilage.
eg. joints between sternum and ribs, between each vertebra (except sacrum and coccyx), and pubic symphysis
permits small range of movement
dissipate stress and absorb shock
24
Q
synovial - freely moveable joints
A
most common joint
allow free range of movement between articulating surfaces of bones
6 primary types - each restricts or permits certain movements
many differences and similarities between
25
types of synovial joints
```
hinge
ball and socket
pivot
gliding
saddle
condyloid
```
26
diaphysis
/ 'shaft'
compact bone tissue = provides strength and support to skeleton
hard outer layer
27
epiphysis
end of the bone
largely made up of cancellous bone (spongy bone tissue)
cancellous bone tissue fills bone space in latticework
spaces within lattice help reduce weight of bone and allow room for bone marrow and blood vessels
lattice also reduces strength = more prone to fractures
28
periosteum
hard outer casing of bones
attachment site for muscles
largely composed of dense, compact bone - much greater tensile strength
29
articular cartilage
smooth, white glossy tissue - furnishes end of bones
ensures smooth, fluid and lubricated movement between articulating bones
cartilage can also soak up synovial fluid which helps absorb shock
30
medullary cavity
within the central component which contains yellow bone marrow
towards epiphysis, internal structure become spongier or more cancellous - where red bone marrow is
31
epiphyseal plate
plate of hyaline cartilage - located between diaphysis and epiphysis
found exclusively in children and adolescents - in adulthood plate fuses and is replaced with epiphyseal line.
source of all bone growth during development
32
hinge joint
eg knee and elbow, joints between phalanges of fingers and toes
permits flexion and extension
in knee - very small amount of rotation is possible but only in flexed position
33
ball and socket
head of one bones articulates with cavity of another
eg shoulder and hips
permits most movement of joints
34
pivot
two articulating bones that move around each other in a rotating fashion
eg joints between radius and ulna (radioulna joint) and between cervical spine and cranium
35
gliding
when almost flat articulating surfaces glide over each other in opposite directions
eg carpals in hands and acromioclavicular joint (shoulder girdle)
permits extension, flexion, elevation and depression
36
saddle
convex shape of one bone fits into concavity of another
not v common
egs base of thumb or between sternum and clavicle
movement permitted = flexion, extension, adduction, abduction, rotation
37
condyloid
/ 'ellipsoid joint'
modified form of ball and socket - ball of projecting bone is more oval shaped and depth of socket is much shallower
egs. wrists, between metacarpals and phalanges
modified version in sub-talar joint of foot
movement it permits == flexion, extension, abduction, adduction and circumduction
38
synovial fluid
thick, sticky fluid
acts as a lubricant with the joint
contains several vital nutrients that help to nourish the cartilage and surrounding structures
synovial joints rely on synovial fluid to keep joints healthy and nourished
39
joint capsule
highly flexible structure - made from dense, irregular collagen and elastin fibres which encase space between two articulating bones
sometimes provides extra stability
40
collagen
collagen fibres found in tendons and ligaments - arranged in regular rope like pattern = means can withstand high tensile stresses
cartilage also contains collagen fibres - arrangement more lattice shaped (irregular) - cartilage acts more like a sponge, absorbing and transmitting shock and impact.
41
tendons
white fibrous bands - made up of regular collagen fibres - that attach muscle to bone - sometimes to other connective tissues
contained within muscle sheath
great tensile strength
somewhat inelastic and limited blood supply = greater risk of injury + slower healing process
tendons can shorten if not used (like ligaments)
usually form by unity of the perimysium, endomysium and epimysium
achilles tendon - can act as a spring, storing energy - enhances efficiency of ankle joint and 'powers' each subsequent step
42
pectoral girdle
/ 'shoulder complex'
composed of scapula, sternum and clavicle
includes the glenohumeral joint, acromioclavicular joint and the sternoclavicular joint
summation of these three individual, yet interdependent joints, give the upper limbs a greater range of movement, making it much more mobile than the pelvic girdle
43
functions of the pelvis
1) to support and protect internal organs
2) support weight of body by transmitting load and force through vertebrae across sacroiliac joint and into the legs
3) promotes neutral spine by supporting vertebral column
4) provides attachments for important skeletal muscles
5) in females provides support to bones of birth canal
44
acetabulum
formed by fusion of the ilium, ischium and pubis to form y shaped cartilage. this fusions occurs between 16-18 years of age.
it is the cavity that articulates with the femur to form hip joint
45
pubis
angulated bone which projects medially and superiorly from the ischium and towards ilium
46
pelvic girdle
oval shaped ring of flat bone
provides articulation for the lower limbs with the trunk
consists of two innominate bones and the sacrum.
both innominates are joined together posteriorly by a synovial joint at the sacrum (sacroiliac joint) and anteriorly at the pubic bone by a cartilaginous joint
each innominate bone is composed of the ilium, ischium and pubic bone, which together create the acetabulum of the hip joint
47
bursae
small fluid filled sacs lined by synovial membrane with an inner capillary layer of viscous fluid
located around most major joints of body
provide cushions between bones and tendons and/or muscles around joints and help reduce friction between these structures, promoting free movement
can become inflamed, causing pain and restricted movements - known as 'bursitis'
48
hyaline/articular cartilage
articulating surfaces of adjoining bones are reciprocally shaped according to their time - means they interact well to create a functioning synovial joint
surfaces of interactive bones are covered with a thick, durable glossy sheet of hyaline cartilage that ensures that smooth and lubricated movement can take place at the joint
hyaline cartilage within a synovial joint is often referred to as articular cartilage
49
the scapula
large triangular plate of flat bone
situated on the posterior and lateral surfaces of thorax
no bony connection with vertebral column, so is held in place with the clavicle and a vast network of skeletal muscles
it is wider superiorly and has two primary processes (acromion and coracoid) and one cavity (glenoid fossa).
diagonal ridge of scapula is referred to as the spine.
the almost vertical inside edge is defined as the medial border (nearest the spine)
lowest point of scapula is defined as the inferior angle.
50
the clavicle
horizontal long bone that acts as a strut to hold the scapula laterally in place.
lateral end of the clavicle (the acromion end) joins with the acromion process of the scapula = acromioclavicular joint
medial end of clavicle (sternal end) articulates with sternum to form sternoclavicular joint
with scapula this forms the shoulder girdle
clavicle is often fractured if it sustains a direct blow or impact
51
glenohumeral joint
formed by articulation of glenoid fossa of scapula and head of humerus.
glenoid fossa acts similarly to the acetabulum of the pelvis - but it is much shallower so has larger range of movement
this greater movement range also reduces stability = increased risk of dislocation
stability of this joint relies on group of deep muscles called 'rotator cuff' - damage to them will result in poor biomechanics of shoulder
gleno joint allows - extension, abduction, adduction, rotation and circumduction
52
acromioclavicular joint
connects the lateral end of clavicle to the acromion process of the scapula.
joint is commonly injured during contact sports - only need moderate impact to dislocate
no muscles directly crossing joint - movement created by force being exerted on other areas of scapula
53
sternoclavicular joint
provides the only point of bony connection between the upper limbs and the trunk
formed by articulation of medial surface of the clavicle and the adjacent surface of the sternum
functions similar to ball and socket but is classified as saddle joint
contains cartilaginous disc for additional strength and protection
permits - elevation, depression, protraction and retraction
54
the elbow joint
synovial hinge joint
formed by articulation of humerus, radius and ulna
proximal end of the ulna comprises of two processes - olecranon process (larger process) and tochlear notch.
together they create concavity in which the tochlear of humerus sits.
articulation of humerus and tochlear prevents hyperextension of elbow
elbow joint only permits movement in sagittal plane so it can only flex and extend
proximal radioulna joint is situated just below elbow joint. created by the articulation of slightly shorter radius and slightly longer ulna. - only permits transverse movement
55
synovial membrane
created from connective tissue which creates and contains synovial fluid
lines the inside of a joint capsule and produces synovial fluid
when the articulating bones of the joint they create friction which stimulates the membrane to produce more synovial fluid
56
ligaments
bands of tough, fibrous, dense connective tissue
function is to connect two articulating bones of the joint together - prevent unwanted movement/dislocation
some ligaments prevent movement all together whilst others permit some
primarily made from two proteins, collagen and elastin.
ligaments throughout body have varying levels of collagen and elastin depending on stability and flexibility required
they can hypertrophy when stressed or overloaded
when damaged slow to heal - poor blood supply
if stretched beyond their normal range they will not revert back to their original length = less stable joint
may shorten if not used
57
bone development
1) formation of bone collar around hyaline cartilage model
2) cavitation of the hyaline cartilage within the cartilage model
3) invasion of the internal cavities by the periosteal bud and spongey bone formation
4) formation of the medullary cavity as ossification continues
5) ossification of the epiphyses: when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilages
58
bone repair
similar to bone growth - primary mechanism is driven by osteoblasts
however reason for osteoblast activity is damage to periosteum and not loading of bone
periosteum has large blood supply so when damaged , bleeding will occur between membrane and bone
osteoblasts then come to blood clot - via process of ossification, blood clot becomes calcified and begins to form new bone tissue.
osteoclasts make sure the new bone is as close to its original size and shape as possible
59
the wrist and hand
the wrist (radio-carpal joint) is formed by articulating surfaces of the radius, ulnas and carpals.
movement never occurs from here in isolation
synovial condyloid joint capable of flexion, extension, abduction, adduction and circumduction
particularly prone to repetitive strain injuries like carpal tunnel
base of thumb is saddle joint - flexion, extension, abduction, adduction
circumduction and opposition to these movements takes place from carpometacarpal joint of the thumb.
movements of fingers (phalanges) includes flexion and extension, with adduction and abduction occurring at the metacarpal-phalangeal joints
60
pelvic gender differences
when the anatomical structure of the female pelvis is combined with tissue-relaxing hormones of pregnancy (relaxin), complications associated with the symphysis pubis joint can present.
diastasis symphysis occurs when this joint starts to separate, while pubis symphysis disorder (PSD) occurs when the joint excessively twists
61
Sacroiliac Joint (Pelvis)
a synovial gliding joint anteriorly and a fused joint posteriorly
62
Symphysis Pubis Joint (Pelvis)
cartilaginous joint formed by the medial surfaces of the two pubic bones
the area of articulating surfaces is covered with hyaline cartilage, which is joined to the cartilage of the opposite side by a disc made from fibrocartilage - thicker in females
no movement between two pubic bones
during pregnancy the ligaments associated with this joint allow small degree of movement for childbirth
63
the q angle
- Formed by the interaction between two axes
- The first axis is vertical and runs through midline of patella and inline with tibial tuberosity
- The second axis is diagonal and runs from the anterior superior iliac spine
- When the q angle is greater than 15 degrees the knee deviates medially and places additional strain on the hip, knee and ankle
- This is particularly prevalent in those who over-pronate
- Pain may also be present in lower back at sacroiliac joint
- Over-pronation can be controlled with corrective insoles
64
hip joint
- iliofemoral joint
- located on inferior and lateral surface of pelvic girdle
- connects lower limbs to the trunk
- plays crucial role in the transmission of force and impact when standing or moving.
- created by the head of the femur inserting into the acetabulum of the innominate bone (ball and socket)
- whole neck of femur is not completely covered by the acetabulum which increases its potential to fracture if it sustains sufficient impact
- can be covered eg by squatting with feet wide.
65
the foot and ankle joints
ankle joint is a synovial hinge joint - formed by articulating surfaces of the tibia, fibula and talus bone.
joint is set slightly diagonally which rotates the feet laterally to an approximate position of five past and five to the o'clock.
the subtalar joint is a modified gliding joint. formed by the inferior surface of the talus bone and superior surface of the calcaneus.
midtarsal joints form the arch of the foot. absorb shock. it is also the cumulative action of the sub-talar and midtarsal joints that enables the feet to adapt to undulating and uneven terrains in gait.
66
the knee and lower leg
modified synovial hinge joint that functions in sagittal plane. formed by articulation of the femur, patella, tibia and fibula.
when knee is flexed beyond 90 it permits some rotation.
within the knee, the anterior and posterior cruciate ligaments cross to support the tibia and resist shear forces.
main purpose of the medial collateral and lateral collateral ligaments is to further stabilise the knee by resisting lateral stress
menisci are semilunar-shaped cartilage discs on lateral surface of knee. the menisci increases stability, acts as shock absorber and to assist weight bearing throughout the knee.
tendons are separated from bone by bursae.
the tibia - below the knee - primary weight bearing bone. fibula supports the tibia. space between the tibia and fibula is occupied by a fibrous interosseus membrane.
67
biomechanical levers
the musculoskeletal system forms a series of levers which allow the body to create efficient movement patterns.
these levers also allow body to overcome loads that are much greater than the forces the muscles are capable of creating directly.
68
4 essential components of a lever
Lever arm - the bones act as lever arms, especially the long bones
Fulcrum - the joint
Effort - Muscles provide the effort and force needed to overcome the load.
Load - the load can be the application of any external forces applied to the body. For eg, in standing or walking, the load is created by gravitational forces on the body.
69
three types of lever
```
first class lever
second class lever
third class lever
```
70
first class lever
has the fulcrum located midway between the weight/resistance and the force in much the same way that a seesaw would.
eg would be a pair of scissors
not widely found in human body. best example is the altlanto-occiptal joint
the skull is the axis and the effort is generated from the neck flexors and extensors. the load is created by the weight of the head and gravity.
71
second class lever
has the load applied between the fulcrum and the force.
eg. would be wheelbarrow
best example in body is the metatarsalphalangeal joints while performing a heel raise. in this eg the fulcrum is created by the joint at the ball of the foot, the load is the weight of the body and the effort is generated by the gastrocnemius and soleus through Achilles tendon.
72
third class lever
most common in human body
the effort is applied between the resistance and the fulcrum.
more speed multipliers than force multipliers - means they are mechanically inefficient from a force production position, but they are able to generate their forces at higher speeds
anatomical eg = bicep curl
in this scenario, the elbow joint is the fulcrum, the hand with the resistance in it is the load, and the effort is applied from the bicep to the radius, which flexes the elbow.
73
articular cartilage
= 'hyaline cartilage'. forms temporary skeleton of the foetus and infant before bones ossify in ossification. its remains can be seen at ends of bones in synovial joints, the epiphyseal growth plates, and the coastal cartilage of ribs. outer surface has some elasticity which acts as shock absorber. smooth surface means free movement of adjacent bones
74
fibrocartilage
= contains bundles of fibrous tissue which give it great tensile strength, combined with some elasticity, to enable it to resist considerable pressure and deformation. found between vertebrae of the spine (intervertebral discs), the lip of the 'glenoid fossa' in the shoulder joint and the 'acetabulum' of the hip joint. can also be found in 'acromioclavicular', 'sternoclavicular' and 'pubic symphysis' joints.
75
medullary cavity
- deepest component of the bone
- a hollow structure that is packed with a complex vascular network to enable the transportation of blood cells in and out of the bone
76
osteopenia
precursor condition to osteoporosis
| bone density is 10-25% less than a 30 yr old healthy adult
77
osteoporosis
bone density is more than 25% lower than a 30 yr old adult bone
1 in 2 women and 1 in 8 men over 50 will experience an osteoporosis related fracture
elderly and post-menopausal women are at higher risk
78
common fracture sites for osteoporosis
hips
wrists
individual vertebrae in the spine
79
osteocytes
- mature osteoblast cells that have become 'trapped' in the bone matrix
- makeup majority of living cells in adult bone
- play a large role in bone remodelling and repair
- secrete substances through dendrite-like structures that influence recruitment or inhibition of osteoclasts and osteoblasts and the remodelling of surrounding bone
- level of osteocytes activity and substances it secretes are influenced by factors such as mechanical stress on bone, circulating hormones, amount of calcium and phosphorous in bloodstream
80
characteristics of synovial joints
include:
- ligaments
- synovial membrane
- synovial fluid
- articular cartilage
- joint capsule
- tendons
81
ilium
- it is the upper broad blade of bone that provides attachment for muscles and ligaments.
- bone forms the pelvic brim between hip and sacrum
- upper border is the iliac crest which can be seen anteriorly just above waistline
- iliac fossa forms smooth internal concavity of ilium
82
ischium
- the posterior and inferior part of the innominate bone
| - tube like structure which acts as an attachment site for several of muscles crossing hip
83
shoulder joint (humerus/scapula)
ball and socket
| movement = flexion, extension, horizontal flexion and extension, adduction, abduction, medial and lateral rotation
84
shoulder girdle (sternum/clavicle/scapula)
gliding
| movement = elevation, depression, protraction, retraction
85
elbow (humerus/ulna)
hinge
| movement = flexion, extension
86
elbow (radius/ulna)
pivot
| movement = pronation, supination
87
wrist (carpals)
condyloid
| movement = flexion, extension, adduction, abduction
88
thumb (carpus/ first metacarpal)
saddle
| movement = flexion, extension, abduction, adduction, opposition, circumduction
89
fingers (metacarpals/phalanges)
hinge
| movement = flexion, extension
90
hip (pelvis/femur)
ball and socket
| movement = flexion, extension, horizontal flexion and extension, adduction, abduction, medial and lateral rotation
91
knee (femur/tibia)
modified hinge
| movement = flexion, extension, slight rotation when flexed
92
ankle (tibia/talus)
hinge
| movement = plantarflexion, dorsiflexion
93
sub-talar (talus/calcaneus)
gliding (sometimes referred to as a condyloid)
| movement = inversion, eversion
94
toes (phalanges)
hinge
| movement = flexion, extension
95
reciprocal inhibition
when a skeletal muscle contracts, its antagonist must relax
