1. THE MUSCULAR SYSTEM

2. Types of Muscle
Smooth – elongated, spindle-shaped, and flat; one nucleus; no ________; found in walls of hollow internal _____, blood ______, eye; in________; contracts ______; prolonged contractions; doesn’t easily _______
Smooth muscle video (2:53)

3. Types of Muscle
Cardiac – striated, cylindrical, and branched; one nucleus; interlock at ______ disks (allow synchronized _____; specialized _____); found only in the _____; involuntary; extremely resistant to fatigue (enormous # of m________ and myoglobin); pacemaker cells (_____- generate their own impulse; discovered by Theodor Engelmann)
Red arrow?
Blue arrow?
Yellow arrow?

4. Types of Muscle Skeletal muscle video (3:33)
Skeletal – striated, cylindrical; multi________; voluntary; can be involuntary (r_____); made of slow- and fast-twitch fibers
Slow-twitch = ______, endurance, _____ contractions, lots of blood, energy source is _____, duration is hours; contain lots of myoglobin (oxygen and iron-binding protein)
Fast-twitch = ______, quick bursts, less blood, energy source is _____ and ___________, duration is up to 30 min; nerves run throughout the muscle (innervated); not as much ________
Fast twitch energy: ATP and glycogen
Skeletal muscle video (3:33)

5. General Functions of Muscle
Stabilizes ________
Allows us to remain _____
Produces _____ (body, breathing, digestion, circulation, birth, excretion)
Contraction produces ______ (helps maintain body _____)

6. Muscle Anatomy (skeletal)
muscle  fascicle  muscle fiber  myofibril  actin(thin)/myosin(thick); sarcomere
_____
_____
_____
_____
_____
_____

7. Sliding Filament Theory
Sliding filament theory – when a myofibril contracts, the _____ filaments slide past the _____ filaments, causing the myofibril, and therefore the muscle fiber, to _____ and _____

8. Events at Neuromuscular Junction
1. Nerve impulse reaches _____ terminal (AT)
2. Ca2+ protein channels _____ and Ca2+ floods AT
3. Ca2+ causes synaptic _____ in AT to release ACh
4. ACh diffuses across _____ _____ and binds with protein receptors in the _____ of muscle fiber
5. ACh binds to sodium-potassium pump in the sarcolemma, causing the pump to allow the simultaneous passage of Na+ ions _____ and K+ ions _____ _____ the muscle fiber
6. When stimulus _____, the enzyme acetylcholinesterase _____ _____ ACh and the process ends

9. Events at Neuromuscular Junction
NMJ Animation (3:15)
What’s the purpose of the junctional folds?
Why are they found only at the NMJ of the sarcolemma?

10. Neuromuscular Junction

11. Generation of ATP Working muscles generate _____ in three ways:
1. Direct phosphorylation of ADP by creatine _____ (anaerobic; only in muscle fibers)
CP supplies exhausted in ~ 20 seconds
2. Lactic acid _____ (anaerobic)
3. Aerobic respiration (generates the most ATP)

12. Muscular System Terms
Prime mover – muscle that provides the major _____ for producing a specific movement
Synergists – assist ____ ____ by providing more _____ and preventing unnecessary movements
They enable us to have smooth, fluid movements
Antagonists – muscles that _____ the movement of a ____ ____

13. Muscular System Terms
Isotonic contraction – muscle contraction that causes _____
Isometric contraction – muscle contraction that causes ____ _____

14. Muscular System Terms Tone – continuous, partial _____ of a muscle
Hypertrophy – _____ in tissue size without cell _____
Increase in muscle mass due to forceful _____
Atrophy – the _____ ____ of tissue due to lack of _____

15. Muscular System Terms
Origin – point of _____ of a muscle; the end that does not _____
Insertion – point of _____ of a muscle; the end that does _____

16. Muscular System Terms
Latent period and contraction & relaxation phases
Latent – muscle prepares for _____
Contraction – ____ and ____ bind together; muscle _____
Relaxation – actin and myosin _____; contraction _____

17. Muscular System Terms Summation, tetanus, & fatigue
Summation – occurs when a skeletal muscle is _____ a second time before _____ is complete; contractions after second and subsequent stimuli progressively _____
Tetanus – occurs if the stimulus is _____ at a sufficiently high rate; the muscle will not _____ between each stimulus but will remain _____
Fatigue – occurs if a muscle is not allowed to _____; muscle _____ even though _____ continues to be administered; muscle has depleted _____ supply; serves as a protective mechanism against _____ to sarcolemma and sarcoplasmic reticulum

18. Summation, Tetanus and Fatigue

19. Muscular System Terms
All-or-none law – muscle fibers either _____ maximally or ____ at ____
Oxygen debt (EPOC) – occurs during the recovery period; even though muscles are _____, _____ rate is still high – Why, you ask? Good question!
1. _____ levels (and therefore ____ levels) in cells must be replenished to pre-exercise levels
2. Assists in the metabolism of _____ in _____ cells
3. Many cells and tissues throughout the body are still _____ after _____ (e.g. sweat glands, muscles, nerves)

20. Muscle Nomenclature
Muscles are named according to a number of characteristics.
This system of nomenclature makes learning their names and functions easier.
The characteristics are:
_________ (gluteus maximus)
_________ (deltoid)
___________ ___ _________ (rectus abdominis)
_____________ (frontalis)

21. Effects of Aging Muscle deteriorates and replaced by _______
Mitochondria break down  decrease of ________
Water content in tendons decreases = stiffness/pain
Less blood flow (oxygen) to muscle cells = less ________ respiration = less production of ______