Chapter 8 - exam 2 Flashcards
how is skeletal muscle attached to bone
by connective tissue = tendons
What is the origin mean of skeletal muscle
end of muscle attached to bone that doesnt move
What is the insertion mean of skeletal muscle
opposite end fixed to bone that moves during contraction
Explain the complete breakdown of structures in skeletal muscle down to the smallest unit
thin and thick filaments –> myofibrils –> muscle fiber (muscle cells) –> fasicle –> muscle bundle
What is the sarcolemma
casing outside muscle fiber that makes up a fasicle
What are the two subpopulations of mitochondria of skeletal muscle fibers
1) subsarcolemmal (SS) mitochondrion
2) intermyofibrillar (IMF) mitochondria
What are Subsarcolemmal (SS) mitochondria
- located directly beneath cell membrane (sarcolemma) - effect membrane potential and flow of ions to create potential
- produce cellular energy needed to maintain active transport of ions across the sarcolemma
What are Intermyofibrillar (IMF) mitochondria
- located near myofibrillar (contractile) proteins
- provide E needed to sustain muscle contraction
Satellite cells are a type of _______ and are important in what
type of myoblast and important in muscle growth/repair
- during muscle growth, satellite cells increase number of nuclei
satellite cells do what with nuclei
produce nuclei and transport them to muscle fiber
having more satellite cells allows for what synthesis
more satellite cells = more nuclei = greater protein synthesis
- important for muscle growth in response to strength training
on untrained muscle what happens with first training and afterwards with detraining and retraining
after first training satellite cells bring more nuclei onto muscle cell –> creating more protein synthesis and causing hypertrophy –> after detraining atrophy is the result and muscle shrinks —> with exercise get back to hypertrophy
What are the 3 functions of skeletal muscle
1) force production for locomotion and breathing
2) force production for postural support
3) heat production during cold stress
skeletal muscle produces what in response to contractions
produces myokines
What are the three functions of myokines
1) stimulate glucose uptake and fatty acid oxidation – b/c during exercise need more glucose in the cells and break down fatty acids
2) promote blood vessel growth in muscle
3) promote liver glucose production and triglyceride breakdown
- ned more glucose in muscles to perform force
What is IL-6
immune response
- both proinflammatory and anti-inflammatory
- produced during exercise and promotes anti-inflammatory effect
- increased glucose production in liver w/ exercise
does regular exercise promote anti-inflammatory, pro-inflammatory or no inflammatory environment
anti-inflammatory
- reduce chronic inflammation (vasodilate) and reduced risk heart disease, type 2 diabetes and certain cnacers
when is IL-6 hightest
during exercise and decreases after
What do flexors do
decrease joint angle
what do extensors do
increase joint angles
What is static movement
- muscle exerts force w/o changing length
- pulling against immovable object
-postural muscles
What are the two types of dynamic movements
1) Concentric
2) eccentric
What is Concentric dynamic movement
muscle shortens during force production
What is eccentric dynamic movement
- muscle produces force but length increases – resisting
- associated with muscle fiber injury and soreness “healthy” injury
- during workout focus on eccentric