Lecture 2 - Terminology, landmarks and skeletal system Flashcards
1
Q
Describe what is meant by the anatomical position
A
The anatomical position describe the body position from which the directional terms always reference:
- Person stands erect
- Feet parallel, flat on the floor
- Arms at the sides of the body, palms facing forward
2
Q
Describe the following body positions:
Supine
Prone
A
- Supine describes the body facing up
- Prone describes the body lying down
3
Q
Define the following terms:
Distal
Unilateral
Medial
Proximal
Lateral
Posterior
Superior
A
Distal - further from the trunk
Unilateral - on one side only
Medial - towards the midline
Proximal - Nearer to the trunk
Lateral - away from the midline
Posterior - nearer the back (dorsal for NS)
Superior - towards the top
4
Q
Explain the difference between the following planes:
- Coronal
- Sagittal/Medial
3.Horizontal/transverse/axial
A
- Separating the body front and back
- Separating the body left and right
- Separating the body top and bottom
5
Q
List 4 functions of the human skeleton
A
- Provides the body framework
- Forms boundaries (skull, thorax)
- Permits movement (joints)
- Haematopoiesis (formation, development of blood cells in the red bone marrow)
- Mineral homeostasis (calcium, phosphate, magnesium)
- Triglyceride storage (yellow bone marrow)
- Protection (ribs)
6
Q
Which bone building cells synthesise and secrete collagen and other components of bony matrix?
A
Osteoblasts
7
Q
What are mature bone cells called and what is their function?
A
Osteocytes maintain the daily metabolism of bone such as nutrient and waste exchange
8
Q
Which bone cell can transform into an osteocyte?
A
Osteoblast
9
Q
Describe 3 features of compact bone
A
- Haversian canal: space for the blood vessels and nerves
- Lamallae: concentric rings of calcified extracellular matrix containing minerals and collagen
- Canaliculi: a mini system of interconnected canals that provides a route for nutrients and waste
- Lacunae: small spaces between the lamellae and osteocytes
10
Q
What is the structural unit of compact bone called?
A
An osteon
11
Q
What percentage of the skeleton is compact bone?
A
80%
12
Q
Where is compact bone located?
A
Compact bone (or cortical bone) is found beneath the periosteum (two-layered vascular membrane) of all bones and makes up the bulk of the diaphysis of long bones.
13
Q
Explain what is meant by resorption
A
The breakdown of bone matrix
14
Q
Describe 2 features of spongy bone
A
- Spongy bone consists of an irregular lattice of think columns called ‘trabeculae’ that are arranged along lines of stress.
- Microscopic spaces between the trabecular make the bone lighter and contains red bone marrow, which produces blood cells, as well as blood vessels that nourish the bone.
15
Q
Where is spongy bone located in the body?
A
In the interior of short, flat and irregularly shaped bones and the ends of long bones.
16
Q
Why is spongy bone always covered by compact bone?
A
Because spongy bone is much softer and vulnerable to injury, it is always covered by hard and protective company bone.
17
Q
What is the most abundant mineral found in bone?
A
Calcium phosphate (which combines with other minerals such as magnesium, sulphate and potassium).
18
Q
Name 5 examples of a long bone
A
Femur
Tibia
Fibula
Humerus
Radius
Ulna
19
Q
The epiphysis is separated from the diaphysis by the __________ plate, which is a layer of _________ cartilage that allows the diaphysis to grow in length. The epiphysis contains a region of thin outer _________ bone covered by hyaline cartilage. There is an inner spongy bone with _______ bone marrow. The diaphysis contains an outer compact bone covered by ____________. It contains a central ___________ cavity that contains ________ and ___________ bone marrow.
A
epiphyseal growth
hyaline
compact
red
periosteum
medullary
red
yellow
20
Q
What is the periosteum?
A
The periosteum is a pain-sensitive, highly vascular membrane that protects bone and serves as an attachment for ligaments and tendons.
21
Q
What do the following terms mean:
- Diaphysis
- Epiphysis
A
- The tubular shaft of long bones
- The proximal and distal ends of long bones
22
Q
What is the periosteum? Describe 3 functions thereof.
A
The periosteum is a pain-sensitive, highly vascular membrane that protects bone and serves as an attachment for ligaments and tendons.
23
Q
Describe the difference between the inner and outer layers of the periosteum.
A
The outer layer is tough and fibrous and is protective. The inner ‘osteopenic’ layer contains osteoblasts and osteoclasts, assisting in bone growth and repair.
24
Q
Apart from long bones, name 4 types of bones and list 1 example for each bone.
A
Short bones: carpals, tarsals
Irregular bones: vertebrae
Flat bones: cranium, scapula, pelvis
Sesamoid bone: patella
25
Describe the difference between intramembranous and endochondral ossification
With intramembranous ossification, bone develops from connective tissue sheets. All flat bones develop this way (skull, clavicles etc.)
In the case of endochondral ossification, bone develops by replacing hyaline cartilage
26
Identify which bone grows lengthwise.
Long bones elongate from the epiphyseal growth plate until the early twenties.
27
List 2 factors that influence bones to grow in thickness
Physical stress
Muscle activity
Weight
28
Explain the role of the epiphyseal plate.
During childhood, long bones continue to lengthen because the epiphyseal plate (made of cartilage at each end of the bone) continues to produce new cartilage on its diaphyseal surface. This cartilage is then turned to bone.
29
Name 2 hormones that promote osteoblast activity.
Growth hormone
Calcitonin
30
Name 2 hormones that promote osteoclast activity
Parathyroid hormone
Cortisol
31
Name 2 glands in the body that regulate calcium exchange.
Thyroid gland
Parathyroid gland
32
Describe in detail what happens to restore balance when:
1) blood calcium is low
2) blood calcium is too high
1) Sensors pick up low levels of blood calcium and parathyroid hormone is released which stimulates osteoclast activity, releasing calcium into the blood from the bone (resorption). The kidneys are also stimulated to reabsorb and retain calcium in the blood. Furthermore the formation of calcitriol is increased, which promotes calcium uptake from food in the intestines.
2) Sensors pick up high levels of calcium in the blood, stimulates the releases of calcitonin from para-follicular cells in the thyroid gland, which promotes osteoblast activity. This leads to the absorption of calcium back into the bone, and thus increased bone formation.
33
Describe the role of the following vitamins and minerals in the regulation of blood calcium
a) vitamin D
b) vitamin K2
c) magnesium
a) Vitamin D3 assists the absorption of calcium from the intestinal tract into the blood
b) Vitamin K2 activates a protein called osteocalcin which controls utilisation of the calcium in the body
c) Magnesium is a co-factor needed for the conversion of Vitamin D in the body
34
Name 2 reasons why a patient might be deficient in Vitamin D
- Lack of sun exposure
- Reduced dietary absorption
- Reduced ability to produce active form of vitamin D (Calcitriol) in the skin, liver and kidneys
35
In the body, mechanical stress leads to increased __________ deposition and increased __________ production.
mineral
collagen
36
Does parathyroid hormone increase or decrease blood calcium?
Increase
37
What type of exercise promotes bone building and why is it important?
Weight bearing exercise builds bone in that it ensures bone formation occurs more quickly than bone resorption. Lack of stress on bones can cause mass loss of up to 1% per week eg/ bedridden patients and is a risk factor for osetoporosis.
38
Explain the difference between the axial and the appendicular skeleton?
The axial skeleton is the 'central skeleton' and contains 80 bones including the skull, inner ear bones, hyoid, thoracic cage and vertebral column. It servces to protect the body's most vital organs.
The appendicular skeleton consists of the bones supporting the extremities/limbs and has 126 bones. These are the shoulder girdle, arms, hands, pelvic girdle, legs and feet. They function to enable movement as well as organ protection.
39
How are skull bones joined together?
With fibrous joints (sutures)
40
Name 2 functions of the vertebral column.
- Protection for spinal cord
- movement (side bending)
- support of skull
- forms axis of the trunk
41
What 4 regions are the vertebral column divided in and how many vertebrae is in each?
Cervical (7) C1-C7
Thoracic (12) T1-T12
Lumbar (5) L1-L5
Sacrum (5 fused) and coccyx (4 fused)
42
How many vertebrae do humans typically have?
24 movable vertebrae plus a group of 5 and 4 fused vertebrae, which results in a total of 26 (or 33 if counting the fused ones separately).
43
Describe the role of the intervertebral discs in the bodyers
Discs are shock-absorbing structures
They bind vertebral bodies and separate individual vertebrae
44
When are intervertebral discs most hydrated?
In the morning and in those aged 30-40 years
45
Which 2 bones make up the shoulder girdle?
Clavicle and scapula
46
Where in the body do we find carpals, metacarpals and phalanges?
In the wrist, hand and fingers
47
Which bones comprise the pelvic girdle?
Hip bones
Sacrum
Coccyx
48
Name the longest and strongest bone in the body
Femur (thigh bone)
49
Explain how muscles are attached to bones
Skeletal muscles are attached to bone via tough fibrous structures called tendons
50
What is the role of joints in the body?
Joints connect two bony structures and permit varying degrees of movement
51
Name 3 types of joints
1. Fibrous - sutures in skull
2. Cartilaginous - intervertebral discs; epiphyseal plate
3. Synovial - shoulder, hip, elbow, knee
52
Give 2 examples of joints that allow for little or no movement
- Sutures in skull
intervertebral discs
53
Describe the structure of the joint
Bones at the joints are covered by a layer of hyaline cartilage (articular cartilage), reducing friction and absorbing shock.
These joints contain synovial fluid (consisting mostly of hyaluronic acid and interstitial fluid), but no direct blood supply, Therefore, movement is essential to aid diffusion of these from the blood. Examples are hinge joints and 'ball and socket' joints.
54
Name the 2 regions that make up intervertebral discs
Annulous fibrosus - outer rim of fibrocartilage
Nucleus pulposus - central core of soft gelatinous material
55
List 1 example for each of the following joints:
a) Ball and socket
b) hinge
a) shoulder, hip
b) elbow, knee
56
Describe the main role of the bursae
These closed fluid-filled sacs are strategically positioned to cushion and reduce friction in areas where bone would otherwise rub on muscle, tendons or skin
57
Structurally, name 2 general locations for bursae in the body
Between skin and bone; tendon and bone; muscle and bone or ligaments and bone
58
Define the following term with regards to angular movements:
1. Flexion
2. Extension
3. Rotation
4. Lateral flexion
5. Abduction
6. Adduction
1. Decrease in joint angle
2. Increase in joint angle
3. Movement around it's longitudinal axis
4. Movement of trunk away from the midline
5. Movement away from the midline
6. Movement towards the midline
59
With regards to special movements, define the following:
1. Elevation
2. Depression
3. Protraction
4. Retraction
5. Inversion
6. Eversion
7. Dorsiflexion
8. Plantar Flexion
9. Supination
10. Pronation
11. Opposition
1. Elevation - superior movement
2. Depression - inferior movement
3. Protraction - anterior movement
4. Retraction - posterior movement
5. Inversion - medial movement of sole (turn in)
6. Eversion - lateral movement of sole (turn out)
7. Dorsiflexion - bending foot up
8. Plantar Flexion - bending foot down
9. Supination - forearm movement, palm facing up
10. Pronation - forearm movement, palm facing backwards
11. Opposition - thumb touching fingertips
60
Name the two bones of the forearm
Ulna and radius
61
Name the two bones in the lower leg
Tibia and fibula
62
What could cause bone fractures?
Physical trauma fracture or Pathological fracture [low bone density (osteoporosis), Vitamin D deficiency]
63
What is the difference between a complete and incomplete fracture?
A complete fracture is when the bone is broken (fully separated) into two or more fragments - this could be open (skin perforated) or closed (no soft tissue damage).
In an incomplete fracture, bone is fragmented but not separated into fragments.
64
Describe the four stages of fracture repair
1. Haematoma and inflammation: Blood vessels at the fracture line are broken and blood leaks into the site. Death of local cells and swelling.
2. Fibrocartilaginous callus formation: Phagocytes clean up the debris. Fibroblasts invade and lay down collagen, forming a soft callus (2-3 weeks)
3. Bony callus formation: Osteoblasts replace soft callus with new bone (< 3 months)
4. Bone remodelling: The callus is mineralised and compact bone is laid down. Then osteoclasts reshape the new bone (months - years)
65
What does the common first aid treatment for sprains, ‘RICE’ entail
Rest
Ice
Compression
Elevation
66
What are ligaments?
Ligaments are tough bands of connective tissue that attach bone to bone.
67
Where does joint dislocation commonly occur?
Shoulder and knee (patella)
68
Briefly explain the following:
a. Kyphosis
b. Lordosis
c. Scoliosis
a. A healthy spine will include a thoracic spine kyphosis which can help distribute forces through the spine. [Hyper-kyphosis can occur due to poor posture or secondary to diseases such as osteoporosis.
b. A lordosis describes an increased concavity, as seen in the cervical and lumbar spine [Hyper-lordosis can be genetic or due to pregnancy and can cause muscular fatigue]
c. A scoliosis is a lateral ‘S-shaped curve in the spine [often asymptomatic, but severe cases can cause spinal nerve compression]
69
What is the difference between subluxation and dislocation of the joint?
Subluxation is incomplete or partial joint dislocation.
Dislocation is the complete separation of two bones at a joint and leads to reduced strength and compromised joint function.
70
Define osteoporosis
Chronic, progressive thinning of the bone (‘porous bone’) is characterised by decreased bone mineral density leading to bone fragility and increased risk of fractures.
71
How is osteoporosis diagnosed?
Conventionally, by a ‘dual x-ray absorptiometry’ (DXA scan). On this test, a ‘T-score’ lower than -2.5 indicates osteoporosis.
72
List 3 dietary factors that increase the risk of osteoporosis.
High acid-forming diet ( high sugar and protein)
Low in minerals
Malnourished
Excess sodium, caffeine, fizzy drinks
73
Why would low stomach acid contribute to the development of osteoporosis?
Gastric acid is needed to ionise calcium and assist absorption
74
Name 4 non-diet-related risk factors for osteoporosis.
- Sedentary lifestyle
- Increasing age
- Female and post-menopausal (oestrogen would normally suppress osteoclast activity)
- Drugs (long-term corticosteroid use)
- Low body weight
- Toxins (heavy metals)
- High alcohol and smoking
- Endocrine pathologies (eg. Cushing's, hyperparathyroidism, hyperthyroidism)
75
List 2 signs and/or symptoms of osteoporosis
Asymptomatic until bone reaches critical thinness whereby fractures occur with minor trauma (spine and hips commonly).
Focal pain and kyphotic posture, loss of height.
Pain is aggravated by prolonged sitting, standing, and bending and relieved by lying on the side with knees flexed.
76
Describe the pathological process in osteomalacia and rickets
Osteomalacia and rickets describe the inadequate mineralisation of the bone matrix in spongy and compact bone. It is characterised by decalcification and hence softening of bone, especially in the spine, pelvis and legs.
77
Explain the main difference between osteomalacia and rickets
The onset of osteomalacia is normally in the adult or teenage years while rickets occur in children and prior to the closure of the epiphyseal growth plate. For this reason, children with rickets will display the characteristic bowing of the lower limbs.
78
Explain the main difference between osteomalacia and rickets
The onset of osteomalacia is normally in the adult or teenage years while rickets occur in children and prior to the closure of the epiphyseal growth plate. For this reason, children with rickets will display the characteristic bowing of the lower limbs.
79
What is osteomyelitis and what are the causes?
Osteomyelitis is a bacterial infection of the bone marrow, resulting in necrosis and then bone weakness. It is usually caused by Staphylococcus Aureus infection through the blood supply or following a fracture or surgery. Immunosuppression, diabetes and the use of IV drugs are risk factors.
80
Define osteoarthritis
A degenerative, non-inflammatory wear-and-tear arthritis of the articular cartilage, typically affecting weight-bearing (larger) joints in individuals typically over 50 years of age.
81
What are the signs and symptoms of osteoarthritis?
- Gradual onset of pain, increasing over months/years
- Joint pain and stiffness
- Not associated with systemic symptoms
82
Discuss the primary and secondary causes of osteoarthritis
Primary: Associated with ageing (80% of 65-year-olds have radiological signs of OA)
Secondary: Associated with predisposing factors:
a) congenital
b) trauma (fractures, surgery, meniscal injury)
c) obesity
83
How is osteoarthritis diagnosed?
By x-ray - revealing narrowed joint space, osteophyte (bone spur) formation and squaring of rounded joint surfaces.
84
Describe the pathophysiology of osteoarthritis
1. Articular cartilage wears away to expose the underlying bone.
2. Subchondral bone becomes hard and glossy (eburnation)
3. Remodelling of underlying bone (i.e. thickening)
4. Compensatory bone overgrowth in an attempt to stabilise joint = osteophytes (spurs).
85
How is Rheumatoid Arthritis defined?
It is an autoimmune inflammation of the synovium, potentially affecting ALL organs except the brain.
86
What is the aetiology of Rheumatoid Arthritis?
- Inherited susceptibility to RA is associated with HLA-DR4 and DR1 genetic markers
- Infections such as EBV and Rubella
- Abnormal intestinal permeability, SIBO, smoking
87
Morning stiffness (> 1 hour) is more prevalent in _______-arthritis
Rheumatoid
88
What are 4 signs/symptoms of rheumatoid arthritis?
1. Symmetrical/bilateral in small joints
2. Gradually spreads through more proximal structures
3. Deformity of joints
4. General malaise and fatigue
5. Subcutaneous nodules (around fingers/elbows)
6. C1/C2 subluxation and compression of the spinal cord lead to paralysis and neurological complications.
89
How would blood test results vary in the case of Rheumatoid vs. osteoarthritis?
In the case of Rheumatoid Arthritis, you will see the raised:
- ESR (Erythrocyte Sedimentation Rate)
- CRP (C-reactive protein)
- Rheumatoid factor
90
_______-arthritis symptoms are often worse in the evening
Osteo
91
What are osteophytes?
Bone spurs in osteoarthritis
92
What is eburnation?
Subchondral bone that has become hard and glossy because of wear and tear
93
Describe the pathophysiology of gout
Gout is a type of monoarthritis, characterised by uric acid crystal deposition in synovial joints.
94
Is gout more prevalent in men or women?
Men (10:1)
95
What causes gout?
Dietary: High intake of purine-rich foods (red meat, organ meats, shellfish), excessive alcohol, dehydration (not enough water)
Other: Kidney disease, obesity, hypertension, medications, Type II diabetes
96
What are the signs and symptoms of gout?
Sudden onset of intensely painful, red, hot swollen joints, lasting 12-24 hours. Shiny skin over joint. Usually monoarticular and most often affects the big toe.
Urate crystals can deposit under the skin and produce ‘tophi’.
97
What is the typical allopathic treatment for gout and why could they be problematic?
Allopurinol - hepatotoxic
Corticosteroid injections - can cause indigestion, rapid heartbeat, nausea, insomnia, osteoporosis, glaucoma, indigestion
97
What is Ankylosing Spondylitis?
AS is a systemic autoimmune disease associated with chronic inflammation of the spine and sacroiliac joints, often leading to spinal fusion
98
Describe the pathophysiology of disc herniation
The nucleus pulposis of the intervertebral disc leaks out through the annulus fibrosis. This tends to affect the discs with the highest fluid content, mainly the lumbar (L5/S1) and cervical spine.
99
What is bursitis and which joints does it commonly affect?
Bursitis is the inflammation of a bursa. This commonly affects the shoulder (sub-acromial) and hip (trochanteric). It can be caused by repetetive use (e.g. overhead work when decorating), sudden trauma or an infection.
