Human Musculoskeletal Anatomy Flashcards
What is the Epimysium?
protective sheath/layer, from friction against other muscles/bones
What is the Perimysium?
connective tissue
What is the Fascicle?
bundle of muscle fibres
WHat is the Endomysium?
fibrous connective layer of tissue, insulates each muscle fibre
What is a muscle fibre?
long, cylindrical, multi-nucleate muscle cell
What is a myofibril?
bundles of proteins (actin and myosin) important in muscle contraction
is long cylindrical organelle within muscle fibre
What is the sarcolemma?
muscle fibre cell membrane
What is the sarcoplasm?
fluid (cytoplasm) contains glycogen and fats for energy and mitochondria for production
What is a tendon?
connective tissue that attaches muscle to bone
What is a sarcomere?
repeating segments of a myofibril (smallest structure)
What are the 3 types of muscle?
cardiac, smooth, skeletal
What is cardiac muscle?
found in the heart, muscle is myogenic and is not under conscious voluntary control
What is smooth muscle?
found in gut and blood vessel lining. This muscle is neurogenic and is not under voluntary, conscious control
What is skeletal muscle?
attached to bone, is neurogenic and is under voluntary conscious control
What does neurogenic mean?
contraction initiated by a neurone
What does myogenic mean?
contraction initiated by the muscle itself
What 2 terms can muscle fibres be described as relating to abundance of nuclei?
Coenocytic and Syncytium
WHat does coencytic mean?
a cell that has lots of nuclei because he nucleus has divided by mitosis many times but the cell didn’t divide afterwards
What does syncytium mean?
the presence of many nuclei as a result of the fusion of many cells
What 4 proteins does the ultrastructure of myofibrils consist of?
actin, myosin, troponin, tropomyosin
What is actin?
thin, consists of 2 strands woven around each other. Form thin myofilaments
What is myosin?
thicker, consists of many rod-shaped filament tails with bulbous heads that project from the strand. Form thick myofilaments
What are small subsections of a myofibril called?
SARCOMERE
What does a sarcomere consist of?
z-line, I-band, H-zone, M-line, A-band, myosin, actin, zone of overlap
What is the z-line?
end points of a sarcomere, separating 2 sarcomeres
What is the H-zone?
zone consisting of only myosin
What is the I-band?
zone consisting of only actin
What is the M-line?
attachment site for the thick filaments (myosin)
What is the A-band?
centre of sarcomere contains both thick (myosin) and thin (actin) filaments, spans the H-zone
Where are the stores of glycogen in the body?
muscles and liver
Why do the muscles have a high glycogen store?
may need to respire rapidly during exercise
What stores can the muscles use for energy?
Glycogen - glucose store (large store)
Triglyceride - lipid store
Muscle tissue - protein store (causes some damage to muscles)
What happens in anaerobic respiration?
glycolysis only (without oxygen) produces lactate converted to lactic acid - provides a short release of energy
What is creatine phosphate?
made under aerobic conditions acts as a store of phosphate, as oxygen levels fall creatine phosphate enables the rapid conversion of ADP to ATP. only a very small amount can be stored
What does build up of lactic acid in the muscles cause?
fatigue and cramp
What are the 2 types of muscle fatigue?
neural and metabolic
What is muscle fatigue?
when muscle cannot contract/relax at correct time
decline of a muscle to generate force
WHat is neural fatigue?
nerves cannot generate an impulse
What is metabolic fatigue?
shortage of substances
accumulation of metabolites
lactate reduces the sensitivity of contractile proteins to Ca2+
What happens during sustained exercise (aerobic respiration)?
initially low ATP in muscles is used up quickly
creatine phosphate can then be used to phosphorylate ADP to replenish ATP (also short term)
Anaerobic respiration can produce limited ATP (net 2 ATP) but also produces lactate
Aerobic respiration must take over again due to lack of ATP and lactate build up
What is cramp?
severe involuntary contraction
How does the lactate production cause cramps?
lactate inhibits the Cl- ion effect - this means more likely to release Ca2+ and lactate allows K+ to enhance contraction
What are the features of Fast Twitch muscle?
fatigue rapidly
contract quickly, relax rapidly
store of glucose for glycolysis
anaerobic
low density of capillaries
high glycogen store
few mitochondria
high density of myofibrils
What are the features of Slow Twitch muscles?
Fatigue slower
contract slowly and for longer time
oxygen available even at low partial pressures
aerobic
good blood supply
have many mitochondria
low density of myofibrils
darker in colour
high concentration of myoglobin
What are the cells within the matrix of cartilage called?
chondrocytes
What do chondrocytes do?
responsible for cartilage formation, secrete an extracellular matrix containing elastic material and collagen
WHere are chondrocytes found?
in the matrix, within lacunae
WHat are lacunae?
spaces in the matrix
What is there none of in the matrix of cartilage?
no blood supply, so rely on diffusion from neighbouring blood vessels, metabolism really slow so repair takes a long time
What are the 3 types of cartilage?
Hyaline, Elastic, Fibro
Which cartilage is the weakest?
hyaline
Which cartilage is the strongest?
fibro
Where is hyaline cartilage located?
nose and ends of bones (to prevent friction)
Where is elastic cartilage located?
ear, epiglottis - elastic but maintains shape
WHere is fibro cartilage located?
intervertebral discs, ligaments - for loadbearing
Which cartilage has the highest proportion of collagen?
Hyaline
What does matrix of Elastic cartilage contain?
collagen, and also a network of elastic fibres
WHat does matrix of fibro cartilage contain?
collagen organised in dense fibres, organised in direction of stress, fewer chondrocytes
What is ossification?
process of bone formation by laying down of new bone
What happens to hyaline cartilage in the embryo?
it ossifies, osteoblasts secrete layers of bone matrix around the cartilage and blood vessels invade. In adults hyaline cartilage remains at ends of bones as articular cartilage.
what is an osteocyte?
cell that maintains the bone tissue, continually degrade bone
What is an osteoblast?
cell that forms bone matrix, continually build up bone
WHat is an osteogenic cell?
stem cell (can form any of the bone cells)
What is an osteoclast?
cell that gets rid of deposited material
What is the function of bones?
structural support
protect organs
point of contact for muscles
What are 2 attributes of bones?
compressive strength - can push down length of bone with relative force
tensile strength - can also withstand tensile force (pulling)
What are the 2 types of bone?
spongy bone, compact bone
What is a spongy bone?
ends of long bones and in vertebrae. Network of spaces containing red bone marrow
What is a compact bone?
also known as critical bone, around 80% of skeletal weight and 14% of average bodyweight
70% inorganic provides hardness and strength to bone (compressive force) mostly 2 hydroxyapatite compounds that contain either calcium or phosphate
30% organic provides tensile strength (resistance to pulling apart) mostly comprised of collagen fibres
What structural units are compact bone made up of?
Haversian Systems
How large are Haversian systems?
approximately 1mm apart and a few mm’s long
what is the lamellae matrix produced by?
osteoblasts
WHat do osteoblasts produce?
many products such as collagen, growth factors and enzymes. This forms the matrix
After matrix is formed what will eventually happen?
eventually the matrix calcifies and the cell is trapped in the space called the lacunae
How do chondrocytes communicate with other cells?
Through canaliculi
WHat is the function of the canaliculi?
channels that radiate out of the lacunae into the bone lamellae share information and nutrients between cells
How does each Haversian system in contact with each other?
by volkmann channels
What is the Haversian canal?
provides network of blood vessels to the haversian systems
What are volkmann canals?
they link haversian systems
What makes up the Spinal cord?
cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacrum vertebrae, Coccyx vertebrae
WHat is the cervical vertebrae?
consists of 7 vertebrae, smallest - allows for rotational neck movement
What is thoracic vertebrae?
consists of 12 vertebrae, middle size - allows for lateral movement
WHat is the lumbar vertebrae?
consists of 5 vertebrae, widest, compress and hold weight, gives support
How many vertebrae do sacrum and coccyx consist of?
sacrum 5 fused, coccyx 4 fused
WHat bones do the skull consist of?
carnial protion, facial portion
What bones do the Pectoral Girdle consist of?
Scapula (back) and Clavicle
What bones do the Thoracic cage consist of?
Sternum and ribs
What does the pelvic girdle consist of?
hips, sacrum, coccyx
What bones do the upper limb consist of?
Humerus, Radius, Ulna
What bones do the lower limbs consist of?
Femur, Patella, Fibula, Tibia
What bones do the hands consist of?
CArpels, metacarpals, phalanges
WHat bones do the feet consist of?
tarsals, metatarsals
WHat is the vertebral column?
spine
WHat is a hinge joint?
in fingers, knees, elbows, toes - allow only bending and straightening movements
WHat is a ball-and-socket joint?
in shoulders and hip - allow backward, forward, sideways, and rotating movements
what is a moveable joint?
Joints that allow for movement, like gliding, ball-and-socket, and hinge
What is an immovable joint?
bones of the skull - two or more bones are in close contact, but no movement can occur
WHat is a gliding joint?
(ankles, wrist, spine) - 2 smooth surfaces that slide over one another to produce limited movement
What parts make up the Vertebrae? (vertebral column)
Vertebral body, Vertebral arch, processes, facets, vertebral canal
WHat is the vertebral body?
bears weight and resists compression
What is the vertebral arch?
protects the spinal cord
WHat are processes? (vertebrae)
for muscle attachment
What are facets?
for articulation with adjacent vertebrae, linking together
What is a vertebral canal?
where spinal cord will be
WHat are the features of cervical vertebrae?
larger vertebral canal
vertebroarterial canal - for blood vessels
What are the features of thoracic vertebrae?
superior costal facet for head of rib
processes for attachment to ribs as well as muscles
What are the features of the Lumbar vertebrae?
Large vertebrae body - for loading
small vertebrae canal
Thick vertebral arch - greater protection
larger processes for attachment to larger muscles
What is a lever?
a rigid structure that pivots about a fixed position called the falcrum
What is the effort (lever)?
the force (muscle contraction) applied to the lever
What is the load?
what the lever moves (body part)
What are force magnifiers?
small effort in but a large force out
WHat are distance magnifiers?
effort over a small distance in and same force out, but moves a longer distance
WHat are first order levers?
has fulcrum in the middle, can be a force magnifier
e.g. spine and skull
WHat are second order levers?
has the load in the middle, also force magnifiers
e.g. standing on tiptoes (ankles/feet)
WHat are third order levers?
effort is in the middle
these are distANCE magnifiers
so effort will be greater than load
e.g. biceps and forearm
How does Rickets occur?
When minerals (vitamin D and calcium) are not adequately absorbed
What is Osteomalacia?
weakening of bones in adults
lack of calcium being absorbed into the body
What are the symptoms of Osteomalacia?
bone tenderness, fractures, bow legs and knock-knees
What is treatment of osteomalacia?
exposure to sunlight and a diet with calcium/vitamin D in it
What is Brittle Bone Disease latin name?
Osteogenesis Impertecta
What is the cause of brittle bone disease?
mutation that causes a change in the structure of collagen
replacement of glycine with a bulkier amino acid
What are the symptoms of brittle bone disease?
fractures, poor muscle tone, loose joints
WHat are the treatments of brittle bone disease?
drugs - increase mineral density of bone
surgery - place metal rods in long bones to enable children to walk.
physiotherapy - strengthen muscle and improve mobility
What is Osteoporosis?
reduction in bone density beyond what is ‘normal’
WHat are risk factors of osteoporosis?
low body weight
smoking
being a woman
drinking too much alcohol
ageing
genes
Caucasian or Asian origin
What are symptoms of osteoporosis?
bones are fragile and more likely to break
WHat are treatments of osteoporosis?
weight resistance training to increase bone density
foods rick in calcium and vitamin D
stop drinking alcohol/smoking
What are the 4 types of fractures?
Oblique
Comminuted
Spiral
Compound
What is an oblique fracture?
break occurs diagonally across the bone
What is a comminuted fracture?
bone is broken, splintered or crushed into a number of pieces
What is a spiral fracture?
The break travels around the bone
WHat is a compound fracture?
The bone sticks through the skin
What are treatments for fractures?
anti inflammatory drugs
immobilisation
surgery
How does bone heal?
blod clot forms around the break, callus made of mainly collagen, osteoblasts form new bone, bone remodelling
What is immobilisation?
immobilises (prevents movement) above and below the fracture and holds the fractured pieces in their normal position while the bone heals
What is surgery needed for?
realign the bone
necessary in some where lengthy immobilisation could produce complications
What are the causes of scoliosis?
in around 8 of 10 cases cause is unknown (idiopathic scoliosis)
in about 30 % of cases there is family history suggesting genetic predisposition
WHat are treatments for scoliosis?
back bracing
surgery
physiotherapy
When can surgery be done for scoliosis?
teenagers and young adults who have stopped growing operation is a spinal fusion
WHat is a spinal fusion?
This is a major operation where the spine is straightened using metal rods, screws, hooks or wires, along with bits of bone taken from elsewhere in your body, often the hip.
What is benefit of physiotherapy/exercise for scoliosis?
regular exercise is important. it can help improve muscle strength and may help reduce any back pain
unclear whether it helps scoliosis
What is flat foot?
can cause strain on muscles and ligaments - genetic arthritis or injury
What are knock knees?
normal up to 18 months
can result in older people from lack of vitamin D or calcium
injured shinbone
usually resolves naturally
WHat is arthritis?
a group of condition where joints are inflamed
WHat is Osteoarthritis?>
glycoprotein and collegn in articular cartilage at the ends of the joints are degraded faster than they are rebuilt
products of breakdown released into cavity
inflammation, joint swelling and spurs of bone may grow
What are risks of osteoarthritis?
age (over 45)
weight
repeated flexing of joints
What are treatments of Osteoarthritis?
physiotherapy - (promotes greater contraction force, strengthens muscles, stimulates cartilage)
NSAIDS’s (Non steroidal anti inflammatory drugs, Ibuprofen and aspirin)
Joint replacement
What is Rheumatoid arthritis?
auto immune disorder that attacks the bone and cartilage at joints
inflamed joints, increased blood flow warms the joints and adds to swelling
What are the risks of rheumatoid arthritis?
can be both Genetic and environmental
smoking
high intake if caffeine and red meat
What are treatment for rheumatoid arthritis?
physiotherpay
NSAIDS’s
joint replacement
corticosteroid injections
What are the pros of joint replacement?
pain relief
mobility restoration
better quality of life
WHat are the cons of joint replacement?
blood clots
only last 15-20 years
long recovery
