Muscle Connective Tissue
Motor Unit
Micro anatomy of NMJ & Skeletal Muscle
Steps of Excitation @ NMJ
Contraction
100
What is the outermost layer of Connective Tissue that surrounds muscles?
Epimysium
100
In simple terms, what is a motor unit?
Where the muscular system meets the nervous system
100
What is the Neuromuscular Junction?
Where the synaptic end bulb comes in contact with muscle fiber to signal contraction
100
Step 1
Action potential arrives at the ___ of the motor neuron and causes the opening of ___
Synaptic end bulb
Voltage-Gated calcium channels
100
Define Spatial Summation
Recruitment of more motor units
200
What is the connective tissue layer surrounding individual Muscle fibers?
Endomysium
200
How many ____ are a part of a motor unit?
a) Motor Neurons (1 or multiple)
b)Muscle fibers (1 or multiple)
a) 1
b) Multiple
200
Identify these part of this image
C= Synaptic Vesicle
E= Synaptic End Bulb
F= ACH(Acetylcholine)
200
Step 2
Synaptic vesicles containing neurotransmitter ___ undergo exocytosis
Ach
Acetylcholine
200
Define Isometric Contraction w/ and example
Tension w/ No change in muscle length
ex: Wall sit
300
What is the connective tissue that surrounds fascicles?
Perimysium
300
Describe the ___ of Slow Muscle fibers
a) Contraction speed
b) Force Production
c) Resistance to Fatigue
a) slow
b) small
c) High
300
Identify the parts of the image
A= Synaptic End Bulb
B= Synaptic Cleft
G= Sarco Plasm
H= Axon of Motor Neuron
300
Step 3
ACH is released into the ___ and binds to ___ on the ___
Synaptic Cleft
ACH Receptors
Motor end plate
300
Define Isotonic contraction w/ an example
Tension is constant while muscle length changes
ex: Bicep curl
400
Identify the odd numbers for this image
1= Muscle Fiber
3= Fascicle
5= Skeletal Muscle
7= Tendon
400
Describe the ___ of Fast Muscle fibers
a) Contraction speed
b) Force Production
c) Resistance to Fatigue
a) Fast
b) High
c) Low
400
Identify all parts of the Image
A= Calcium
B= Voltage-gated calcium channels
C= Synaptic Vesicle
D= Motor End Plate
E= Synaptic end bulb
400
Step 4
___ open and allow ___ to enter the muscle fiber, in turn depolarizing the muscle fiber and generating an AP on the sarcolemma
ACH receptors
Na+ Ions/Sodium Ions
400
Define temporal Summation and the size principal
Increased frequency of contraction
Recruiting from smallest to largest for more force, Slow fibers > Fast Fibers with periods of spatial and temporal summation
500
Identify the Even Numbers for this image
2= Endomysium
6a= Perimysium
6b= Epimysium
500
Describe the ___ of Intermediate Muscle fibers
a) Contraction speed
b) Force Production
c) Resistance to Fatigue
a) Fast
b) Medium
c) Medium
500
Identify the Parts of a muscle fiber
A= Synaptic End Bulb
B= Synaptic Cleft
C= Motor End Plate
D= Sarcolemma
E= Myofibril
F= Endomysium
500
Step 5
Acetylcholine (ACH) is broken down by ___ into acetate and choline
Acetylcholine esterase
ACH esterase
500
What are the 2 types of isotonic contraction and define them
Concentric: The muscle is contracting and shortening
Eccentric: The muscle is contracting and lengthening