Structure And Function Flashcards
What is an antagonist muscle
The muscle that controls or works against
What is Concentric
Where the muscle shortens the force is greater than the resistance
What is eccentric
Lengthening of a muscle or force is less than resistance
What is isometric
There is no change it like some examples are posture and wall sits the force equals the resistance
What is isokinetic
The same speed and velocity the machine causes the same amount of speed and angle matter how much force you apply to it
What is the Endomysium
The connective tissue that surrounds it separates an individual muscle fiber
What is the fasciculus
The bundle that contains a group of muscle fibers up to 150
What is the perimysium
Separates the fasciculus
What is the EpiMysium
A dense protective sheath of connected tissue that in cases the entire muscle or muscle group
What is a tendon
Joins muscle to bone
What is the sarcolemma
Membrane that surrounds each muscle fiber it conducts the wave of deep polarization along the surface it also insulates muscle fibers from one another
What is a satellite cell
With in the sarcolemma that regulates growth
What is the sarcoplasm
Hey gelatin with in the spaces of a single muscle fiber it contains lipids glycogen mitochondria
What are the transverse T tubules
They are located in the sarcoplasm. They carry impulses through each fiber and serve as transport vesicles for certain substances
What is the sarcoplasmic reticulum
Stores calcium ions which is crucial for muscle contraction with in each muscle fiber they run longitudinal
What is a myofibril
Allows the skeletal muscle to contract there are thousands of these per fiber and run parallel
What is a myo filament
They are proteins that comprise a myofibril they proteins are actin and myosin
What is the I band
The part that contains only actin
What is the A band
The darker zone it contains Actin and myosin
What is the H zone
The center of the A band where only the myosin is present
What is M line
The center of the H zone and sarcomere
Where is actin anchored to
The Z line
Where is Myosin anchored to
The M line
What is the smallest contractile unit of skeletal muscle
The sarcomere
Explain the sliding filament theory of muscle contraction
The muscle cell receives an actiom potential from a motor neuron. impulse travels in word toward T tubules and sarcoplasmic reticulum the electrical charge causes sarcoplasmic to release calcium ions which bind with troponin which shifts tropomyosin molecules off the actin binding sites. myosin cross bridges attached to binding sites. Actin slides over myosin contracting the muscle
What is the length tension relationship
The lake is dependent on for us because it determines our cross interaction 100 to 120% of length is optimal crossed bridge number. If more than 122 stretched out if less than 100 not maximal. not enough overlap
Describe type one muscle fibers
They are slow twitch aerobic read slow oxidative they are fatigued resistant and have a large number of mitochondria oxygen is the primary they have lower force capabilities. a slower speed of shortening
Describe the type 2 muscle fibers
They are fast twitch at aerobic and white they are prone to fatigue. they use blood glucose and glycogen as a fuel source they have high force capabilities and are fast
Which muscle fiber type has the most extensive anaerobic potential
Type 2X or 2B
What is the only way muscle fiber types change
We can lose type two fibers by age D generation
What muscle is highly a type one fiber
Soleus
What is hypertrophy
Muscle fibers get larger, thicker but not longer or more numbers
What is hyperplasia
Creation of new muscle fibers this can be due to what fiber split it into two but increase in the number of fibers is not documented
What are the three functions of skeletal muscle
Movement posture and heat production
What are the characteristics of muscles
Excitability contractility extensibility and elasticity
What is a motor unit
A motor nerve at the muscle fiber that it innervates each motor neuron on innervates several muscle fibers
What is the low high average number of muscle fibers per motor unit
Low is 10hi is 3000 and average is 100
How is a motor unit made up compared to fiber type
Each motor unit is composed of all types one or all type two there is no mixture
What is the motor unit activation sequence
The action potential arrives at the nerve terminals then there is a release of the Nero transmitter acetylcholine which diffuses across to neuromuscular junction causing excitation of the sarcolemma. Once enough of acetylcholine is released the action potential goes across the sarcolemma and the fiber contracts
What is the all or none principal
Either all of the fibers within a motor unit fire or none of them do similar to firing a gun
What is the motor unit activation sequence
Type one then type two Athen type two X
How do we determine the overall force generated
By the number of motor units recruited
What are muscle spindles
A proprioceptor that is located parallel to the muscle fibers it is stimulated by an increase in muscle length the rate of change is important. It is Hibbetts stretch the muscle big stretch to protect it from extreme ranges of stretch or fast stretches and example is the Knee tap with a rubber mallet
What are the golgi tendon organs
They are located near the muscle tendon junction in series there is stimulated where there is a increase in the muscle tension it inhibits development of the stretch also promotes relaxation that protects from excessive loads
How many bones are there and an adult body and how many and infants
There are 206 in an adult and 270 in an infant
What are the three types of a joint
Fibrous, cartiloginous or synovial
What is a fibrous joints and give an example
Joined by fibrous tissue with limited or no mobility and example is the skull
What is a cartilaginous joint give an example
Joined by cartilage with slight mobility and example is the vertebrae
What is a synovial joint and give an example
Not directly joined permitting a variety of movements examples are the shoulder elbow hip and knee
What is a simple joint
To articulation surfaces such as shoulder and hip
What is a compound joint
Three or more articulation surfaces such as the wrist and ankle
What is a complex joint
Two or more articulation surfaces and it articular disk or meniscus such as the knee and elbow
What is an agonist
For example it is it would be the bicep muscle that work with the movement
What bones are in the axial skeleton
Skull vertebral column sternum and ribs
What bones are in the appendicular skeleton
Shoulder girdles arms legs and hips
What is the cortical bone
It is the dense bone that is in the outer layer it is 80% of skeletal mass and for structural support.it is compact bone
What is the trabecular bone
Porous material that is Latticelike like it is spongy looking and allows for Marrow and fat storage it is about 20% of skeletal mass.it’s has physiological functions
What are the structural and physiological functions of bone
Structural is the physical movement and internal organ protection physiological is for red and white blood cell formation of a storage area for calcium and phosphate
How do bones grow and remodel
There is a longitudinal growth at the epiphyseal or growth plate it is genetically mediated and it usually ceases after puberty. Phone is very adaptable we can remodel when needed
What are the three types of bone cells
Osteoclasts are bone destroying cells.osteoblasts are bone forming cells.osteocytes are mature osteoblasts that help regulate bone remodeling
What is a tendon
Attaches muscle to bone it is a very strong when tenseor on stretch it is not really elastic. Injuries to tendons are common because it ruptures or strains at the end is near the muscle
What is a ligament
It connects bone to bone . it is similar to tendon and example is the ACL females are 5 to 9 times more likely to tear their ACL. Ligaments contain the protein elastin therefore they allow extensibility and the ability to return to the undeformed length
What is the function of fascia
Provide intramuscular framework to find a protect muscles allow muscle forces to be transmitted securely and offers insulation between various organs and tissues of the body
