Muscle 2-respiratory and everything in between Flashcards
isometric contraction
no shortening, muscle tension increased but does not exceed load
isotonic contraction
muscle shortens because muscle tension exceeds load
Motor unit
Consists of the motor neuron and all muscle fibres (four to several hundred) it supplies
Muscle twitch
Simplest contraction resulting from a muscle fiver’s response to a single action potential from motor neuron`
Latent period
events of excitation-contraction coupling
Period of contraction
cross bridge formation, tension increases
Period of relaxation
Ca2+ re entry into SR, tension declines to zero
Concentric contractions
muscle shortens and does work EX: bicep contracts to pick up a book
Eccentric contractions
muscle lengthens and generates force EX: when laying a book down causes biceps to lengthen while generating a force
Three mechanisms that ATP is regenerated by
- direct phosphorylation of ADP by creatine phosphate (CP)
- Anaerobic pathway: glycolysis and lactate formation
- Aerobic respiration
Creatine Phosphate
is a unique molecule located in muscle fibres that donates a phosphate to ADP to instantly form ATP
Slow oxidative characteristics
- Speed of contraction is low,
- Myosin ATPase activity is slow,
- Primary pathway for ATP is aerobic,
- Myoglobin content is high,
- Fiber diametre is small
- Many Mitochondria
- Many capillaries
- Color is red
Fast oxidative characteristics
-Speed of contraction is fast
-myosin ATPase activity is fast
-Primary pathway for ATP is aerobic
-Myoglobin content is high
-Glycogen stores is intermediate
-Fiber diametre is large
-Many mitochondria
-many capillaries
Color is red to pink
Fast glycolysis characteristics
- speed of contraction is fast
- Myosin ATPase activity is fast
- Primary pathway for ATP synthesis anaerobic glycolysis
- Myoglobin content is low
- Glycogen content is high
- fiber diametre is intermediate
- few mitochondria
- few capillaries
- color is white
Describe primary differences between skeletal and cardiac muscles
- Structure
- Gap junctions
- Contracts as unit
- T tubules
- Sarcoplasmic reticulum
Skeletal muscle characteristics
- structure is long striated, cylindrical, multinucleate
- no gap junctions
- no contraction as a unit
- T tubules are abundant
- sarcoplasmic reticulum is elaborate
Cardiac muscle
- structure is long striated, branched, one or two nuclei per cell
- there is a gap junction between cells
- There is a contraction as a unit
- T tubules are wider and there are less of them
- sarcoplasmic reticulum is less elaborate
Bohr effect
downright shift of the O2 dissociation curve. as a consequence of decreased Ph increased body temp and O2 this downright shift of association curve will increase oxygen to working muscles which can be described as an increase in arteriole venus oxidation difference
Hamburger effect
also called chloride shift, is a process which occurs in the cardiovascular system and refers to the exchange of bicarbonate (HCO3) and chloride (CI) across red blood cell membranes
Four factors that muscle contraction is affected by
- Number of muscle fibers stimulated (recruitment)
- Relative size of fibers
- Frequency of stimulation
- degree of muscle stretch
Force velocity relationship
linear but negative relation between force and velocity, there is an inverted U relationship between resistance and power, peak power output corresponds to force and velocity
VO2 max
the maximum rate that oxygen can be taken up from the ambient air and transported to and used by cells for cellular respiration during physical activity
Functions of the blood
- Transport
- Regulation
- Protection
Transport
Delivering O2
Regulation
maintaining body temperature
Protection
Preventing blood loss
Erythrocytes
RBC’s, small diameter(7.5 um) cells that contribute to gas transport; have a biconcave disc shape; filled with hemoglobin for gas transport
Leukocytes
WBC’s
Blood plasma
about 90% water,
Causes of hypoxia
- decreased RBC numbers due t hemorrhage or increased destruction
- Insufficient hemoglobin per RBC(ex: iron deficiency)
- Reduced availability of O2(ex: high altitudes or lung problems)
Spectrin
is a protein that will flexibility to RBC’s
Right atrium
receives blood returning from systemic circuit
Left atrium
Receives blood returning from pulmonary circuit
Right ventricle
pumps blood through pulmonary circuit
Left ventricle
Pumps blood through systemic circuit
Atrioventricular valves
located between atria and ventricles
Semilunar valves
located between ventricles and major arteries
Tricuspid valve
(right AV valve): lies between right atria and ventricle
Mitral valve
(left AV valve, bicuspid valve): lies between left atria and ventricle