Muscular skeletal Flashcards
What is the structure of skeletal muscle?
Long cylindrical cells/ many nuclei per cell / straited / voluntary / produces rapid contractions
What is the structure of Cardiac muscle?
branching cells// contain 1 or 2 nuclei per cell // straited // involuntary // medium speed of contractions
What is the structure of smooth muscle ?
spindle-shaped // central nucelli / nonstriated / involuntary / slow -wave like contractions
What is the difference between isometric and isotonic contraction (using examples)?
ISOMETRIC - produces no movement (e.g. sitting and holding posture ) // ISOTONIC - produces movement (e.g. walking and moving body parts)
What are the different zones in a sarcomere?
M-LINE -> vertical line in the middle section of a muscle cell
A-BAND-> dark region containing thick myosin and some thin actin
I-BAND-> light band containing only actin
Z-DISC-> lateral boundary of the sacrcomere
*also contains actin and myosin
Compare the structure and location of actin and myosin.
THIN ACTIN -> attached to the Z disc, composed of troponin tropomyosin and G actin // THICK MYSOIN - Located from midline outwards and contains a tail and myosin heads
Explain how muscular contractions are created at the microfibril level.
- Myosin cross bridge attaches to actin myofilament // 2. Working stroke - the myosin head pivots and bends as it pulls on the actin filament and slides it towards the M line// 3. As new ATP attaches to myosin head, the cross bridges detaches // 4. As ATP splits into ADP and P, cocking of the myosin head occurs and myosin and actin filaments move creating muscular contraction
Explain the process which occurs at the synaptic cleft to produce muscular contraction.
- action potential generated is propagated along the sarcolemma and down the T tubules // 2. Action potential triggers CA2+ release from terminal cistemae of SR// 3. Calcium ions bind to troponin , troponin changes shape removing the blocking action of tropomyosin activating myosin binding sites // 4. Contraction occurs through myosin movement // 5. CA2+ is removed by active transport // 6. Tropomyosin blockage is resorted and actin reverts back to being inactive
What is the structure and function of the axial skeleton?
Skull and spinal column and rib cage // forming longitudinal part of the body // protects and supports body’s vital organs , spinal cord and brain // provides surface for muscular attachment
What is the structure and function of the appendicular skeleton?
Limbs and girdle / facilitates movement through providing attachment pints for muscles // provides lever systems
How does development impact the skeletal structure and function?
Bones grow in direction to where force is applied
How does ageing impact the skeletal structure and function?
EMRBYO - skeleton is primarily hyaline Cartlidge// DURING DEVELOPMENT - cartlidge is replaced by bone// MATURING AND AGING- Cartlidge remains in isolated areas alike bridge of nose/ phosphorus and calcium mineral content drops making bones more frail
How many bones are there in the body?
206
What are the two types if bone?
COMPACT // SPONGY - small needle like pieces if bones producing may open spaces
Give an example of where each lever type is found in the body.
1st CLASS - neck , tilting the head // 2nd CLASS- ankle, standing on tip toes // 3rd CLASS- elbow, during a bicep curl
What are the different joint types and their function?
FIBROUS - immovable, connects bones and allows no movement // CARTLAGINOUS - slightly movable // SYNOVIAL - freely movable
What is meant by voluntary and involuntary contractions ?
voluntary = consciously controlled // involuntary = contracts automatically without conscious control.
What are some functions of bones?
support // protection// assisting movement // storage of minerals // production of blood cells
Are the biological processes used by tissue to heal and adapt the same?
yes
What is the impact of analgesic and anti-inflammatory drugs on healing?
POSTIVES= reduces pain, swelling and improving initail function
NEGATIVES - inflammation is vital for supplying the injury with necessary cells , removing debris and promoting growth factors to the site
What strategies can be used to treat injury?
RICE - rest , ice, compression and elevation -> aim is to prevent over inflammation// can also hydrate , use ibroprofen / pulse / proetct / diagnose …
What strategies can be used to prevent injury?
tailored training plan/ warm ups and cool downs / hydration/ correct equipment
What is meant by regeneration in response to injury ?
Growth of cells and tissue to replace lost structure with aim to regain original function, however this involves intact connection to tissue scaffolding
What is the difference of labile, stable and permenant cells ? (use examples)
LABILE -> high rate of loss and replacement / high regeneration capacity/ squamous and glandular epithelia e.g. RBC in bone marrow// STABLE -normal non-proliferating cell but can still multiply after damage e.g. hepatocytes (liver cells)// PERMENANT- unable t divide after initial development , cannot regenerate after damage e.g. cardiac and skeletal muscle
What are haemopoietic cells?
mature cells that develop into all types of blood cells, including red blood cells, white blood cells, and platelets
What are hepatocyte cells?
Liver cells which perform many functions including metabolism, detoxification and immune response // an example of stable cells
What is autocrine signalling ?
a type of cell communication where by a cell releases signalling cells influencing its own function
What is paracrine signalling?
a type of cell communication where a cell releases signaling molecules to influence nearby cell
What is endocrine signalling?
a type of cell signalling that uses hormones to transmit messages over long distances in the body.
What are some variables influencing healing?
INJURY- type/ duration and intensity // PATIENT- age / comorbidity (presence of other diseases) / medication// TREARTMENTS success and implication
When does inflammation occur after injury? How does this occur?
0-7 DAYS
tissue is filled with granulation tissue, haematoma and tissue debris, fibronectin laid down as scaffolding for collagen synthesis
When does repair occur after injury? How does this occur?
3-60 DAYS
fibroblast migrate to zone of injury and collagen beings to be synthesised( at day 5) // later intrinsic fibroblasts proliferate and drive the healing process switching production from Type 3 collagen to type 1
When does organisation occur after injury? How does this occur?
28-180 DAYS - cross linking between fibrils further increases tendon tensile strength// however the injury is never healed , there is thinner collagen fibrils and a defect remains hypercellular
Why might muscular injuries heal much faster than others?
High vacsculated therefore have a rich blood supply containing blood cells and signalling
What does NSAID stand for?
Nonsteroid anti-inflammatory drugs-> used to reduce pain and inflammation e.g. ibuprofen
What is a motor unit?
motor neurone + muscle fibres// all the muscle fibres in a motor neurone are controlled by a single nerve fibre
How does the recruitment order and pattern influence a motor units function?
smaller slow twitch motor units are recruited first allowing finer motor control to be obtained// the more motor units recruited -> the greater the force created
What is the limbic system?
a group of interconnected brain structures that help regulate your emotions and behaviour. consisting of : amygdala (emotional centre) / hippocampus (forms movement based on past experiences )/ thalamus (relay centre) / hypothalamus ( maintains homeostasis )/ basal ganglia (filters out unnecessary signals) / cingulate gyrus (pain perception)
How can the limbic system influence skill acquisition?
processes emotions and memories to aid decision making of what motor task is appropriate
What are the two main pathways of descending spinal tracts ?
1.LATERAL -> moves outwards // 2.VENTRAL- oves inwards/ close to spinal cord
What is the role of the lateral descending spinal tract?
produces voluntary(conscious)// originates in cerebral cortex and ends at the spinal cord // consists of Corticospinal tract and rubrospinal tract
What is the role of the ventromedial pathway of the descending spinal tract?
Vestibulospinal tract-> Head balance and turning//
Tectospinal tract -> Orientating in response to visual and auditory stimuli //
Pontine reticulospinal tract->Enhances postural reflexes//
Medullary reticulospinal tract ->Liberates postural muscles for reflex
What part of the brain plans movement ?
MOTOR CORTEX -> decision is based upon auditory cues and additional signals // the posterior and parietal have the highest level of motor control
What is the function of the basal ganglia?
control movement, learning , emotions and behaviour
What are some diseases associated with basal ganglia?
Parkinson’s and Huntington’s
How is saccadic eye movement controlled?
by superior colliculus// inputs involuntarily control and coordinated movement of the head with this
Define proprioreception.
The sense of position and strength of effort
What does the efferent pathway do?
send signals through the CNS to create a function.
What is Heneman’s size principle?
The size principle stating the more force which is needed the more motor units will be recruited in direct proportion
Give some examples of proprioception during the crow in yoga.
BRAIN- receives interpreters info from many inputs// VESTIBULAR ORGANS - within ear , sends info about rotation, acceleration and position// EYES- sends visual info// STRECH RECEPTORS -> in skin muscles and joints about body positioning
What are muscle spindles and what do muscle spindles send info about?
they are small sensory organs enclosed within a capsule// composed of many intrafusal fibers/ detect a change in muscle length,
Where are Golgi tendon organs located and what do information do they tell us?
located within tendons // provides info in the change in muscle tension
What are the 4 main types of mechanoreceptors? And which are associated with slow and rapid adaptations? And what do they respond to?
SLOW-> Merkle receptors (steady pressure changes )+ ruffini cylinde (steady pressure and streching of the skin) / FAST->meissner corpuscles (rubbing against skin / movement against skin) + pacinian corpuscles (changing stimulation)
What are afferent and efferent signals ?
AFFERENT - sensory signals to CNS // EFFERENT -> Motor signals travelling away from CNS
