1. Muscular System

2. How many muscles do we have?
Over 650!
Our over 650 muscles fall into three categories –
1. skeletal,
2. cardiac &
3. smooth.

3. Fun Facts There are 50 muscles in your face alone.
It takes 17 muscles to smile and 40 muscles to frown.
Your heart muscle NEVER gets any rest neither do the muscles of your intestines!
The most active muscles are those in your eyes. They move more than 100,000 times a day!

4. Biggest, Strongest, and Hardest Working
The gluteus maximus is the largest muscle in the human body.
The strongest muscle in your body is the masseter, located on each side of your mouth. These muscles help you bite down with 150 pounds of force!
The hardest working muscle is the heart. Every day the heart pumps at least 2,500 gallons of blood.

5. In one day, your blood travels nearly 12,000 miles.

6. Three Types of Muscle Cells
Skeletal
Cardiac
Smooth

7. Skeletal Muscle a.k.a. striated muscle
Nuclei are on the periphery of the cells

8. 2. Smooth Muscle

9. 3. Cardiac Muscle

10. Do Now! 3. What kind of muscle? 1. What kind of muscle? (C, Sm, Sk?)
4. Lines hollow organs (C, Sm, Sk?)
5. Makes up the heart walls (C, Sm, Sk?)
6. Connected to bone (C, Sm, Sk?)
7. Involuntary (C, Sm, Sk?)
8. Used to push substances along internal passageways. (C, Sm, Sk?)
9. Voluntary (C, Sm, Sk?)
10. Moves bones (C, Sm, Sk?)
2. What kind of muscle?
(C, Sm, Sk?)

11. Practice Practical Muscle Quiz
                                                                      
1. Identify the type of tissue.
A) Dense regular connective tissue
B) Smooth muscle
C) Cardiac muscle
D) Skeletal muscle
2. In question 1, above, what was the most distinctive identifying feature?
Striations
Branched fibers
Peripheral nuclei
A and C
A, B, and C

12.                                                                      
3. Identify this tissue:
A) Dense regular connective tissue
B) Smooth muscle
C) Cardiac muscle
D) Skeletal muscle
4. In question 3, above, what was the most distinctive identifying feature?
A) Striations
B) Branched fibers
C) Central nuclei
D) A and C
E) A, B, and C

13.                                                                                                             
5. This specialized junction separates cells in:
A) Cardiac muscle
B) Skeletal muscle
C) Smooth muscle
D) Tendons

14. 6. Identify this tissue.
A) Dense regular connective tissue
B) Smooth muscle
C) Cardiac muscle
D) Skeletal muscle
E) Dense irregular connective tissue

15. 7. Identify this tissue.
A) Dense regular connective tissue
B) Smooth muscle
C) Cardiac muscle
D) Skeletal muscle
E) Dense irregular connective tissue

16.                                                                          
8. Identify this tissue:
A) Dense regular connective tissue
B) Smooth muscle
C) Cardiac muscle
D) Skeletal muscle
E) Dense irregular connective tissue
9. In question 8, above, what was the most distinctive identifying feature?
A) Striations
B) Branched fibers
C) Peripheral nuclei
D) A and C
E) A, B, and C

17.                                                                            
10. Identify the name of the connective tissue around each fiber:
A) epimysium
B) endomysium
C) perimysium
D) meromysium
E) sarcomysium

18.                                                                         
11. Identify the structures noted by the arrows:
A) striations
B) sarcomeres
C) Intercalated discs
D) Sarcoplasmic reticulum
E) endomysium

19. Skeletal Muscle Fibers
Connect to bones
Forms the smoother contours of the body
Very long and cylindrical in shape
Multinucleated
Largest of the 3 muscle types
A.K.A. Striated muscles
Only muscle type under voluntary control
Can also be activated by automatic reflexes

20. How can they be so strong?
Each fiber is wrapped in connective tissue called endomysium.
Several fibers are then wrapped in a courser membrane called a perimysium to form a fascicle.
The fascicle is bound together by an even tougher cover called an epimysium.
Endomysium

21. The epimysium (outer layer) can blend into strong cordlike tendons or
Into sheet-like aponeuroses (fascia) which attach muscle indirectly to bone, cartilages, or other connective tissue coverings.

22. Label this skeletal muscle using the diagram on the next slide

24. What do you remember?

25. Origin vs. Insertion
The muscles origin is attached to the immovable bone.
At its other end, the insertion is attached to the movable bone.
You’ll need this for lab!

26. The endomysium can be further divided.

28. The myofilaments of a myofibril are arranged in a regular fashion so that their ends are all lined up.
This is what gives the muscle its striated appearance.
The contractile units of the cells are called sarcomeres.

29. Sarcomere
The myofibrils have distinct, repeating microanatomical units, termed sarcomeres.
The sarcomere is composed of thick and thin filaments – myosin and actin, respectively.
Chemical and physical interactions between the actin and myosin cause the sarcomere length to shorten (contract).
The interactions between actin and myosin serve as the basis for the sliding filament theory of muscle contraction.

30. Sliding Filament Theory
The sliding filament theory is the basic summary of the process of skeletal muscle contraction.
Myosin moves along the filament by repeating a binding and releasing sequence that causes the thick filament to move over the thinner filament.
This progresses in sequential stages. By progressing through this sequence the filaments slide and the skeletal muscles contract and release.

31. Naming Skeletal Muscles
Named based on structural or functional characteristics.
1. Direction of fibers: Rectus (straight or parallel to an imaginary line) or oblique (at a slant)

32. Naming Skeletal Muscles
2. Size of muscle:
Maximus (largest),
Minimus (smallest) and
Longus (long)

33. Naming Skeletal Muscles
3. Location of the Muscle
Some are named for the bone they attach are associated with.
Ex. The temporalis muscle lays over the temporal bones of the skull.

34. Naming Skeletal Muscles
4. Number of Origins
Ex. Bicep muscle has two heads, triceps have three and quadriceps have four.

35. Naming Skeletal Muscles
5. Location of Muscle’s origin and insertion.
Ex. Sternocleidomastoid has its origin on the sternum (sterno), and clavicle (cleido) and inserts on the mastoid process of the temporal bone.

36. Naming Skeletal Muscles
6. Shape of the Muscle
If a muscle has a definitive shape, it is used to help identify them.
Ex. Deltoid (triangular)

37. Naming Skeletal Muscles
7. Action of the Muscle
Adductor:
A motion that pulls a structure or part towards the midline of the body, or towards the midline of a limb
Flexor: Closes a joint
Bending movement that decreases the angle between two parts. For ex. bending the elbow, or clenching a hand into a fist
Extensor: opens a joint
a straightening movement that increases the angle between body parts
Abductor: moves away from midline

38. Four functions of skeletal muscles.
Maintain posture
Stabilize joints
Generate heat
Produce movement

39. Aging and Muscles
After 30, your muscle mass dwindles some 3-8 percent each decade. Once you hit 60, these losses accelerate even more quickly.
Decreased muscle mass means you'll burn far fewer calories.
Muscles require a lot of calories to maintain. (Think of them as a bunch of high-strung, active family members visiting your home. They're always up, moving around. As a result, they're hungry and require a lot of food.)
The strength of your muscles is related to the strength of your bones. When your muscles are weak, your bones are more likely to be weak. (This is esp. important for women who have higher risk of osteoporosis.)

40. Muscle Pairs
Muscles are usually in (Antagonistic) pairs. When one muscle contracts, the other extends.
Adrenaline allows your muscles to use 4 to 6 times more oxygen than usual thus creating a huge amount of energy.
Extreme strength:
Two man strength performance:

42. Disorders of the Muscular System
Muscular Dystrophy: Occurs when a particular gene on the X chromosome: a. fails to make the protein dystrophin.
b. makes low amounts of dystrophin.
the membranes around muscle cells become weak and tear easily, eventually leading to the death of muscle fibers.
More common in males.

43. DMD
Types of MD
A. When one of these proteins, dystrophin, is absent, the result is Duchene’s muscular dystrophy.
B. Poor or inadequate dystrophin results in Becker’s muscular dystrophy.
Animation:
A family’s story:

44. Disorders of the Muscular System
2. ALS: Amyotrophic lateral sclerosis: disease of the nerve cells in the brain and spinal cord that control voluntary muscle movement.
AKA Lou Gehrig's disease.
The symptoms usually do not develop until after age fifty.
Persons with this disease have a loss of muscle strength and coordination that eventually gets worse.
Breathing or swallowing muscles may be the first muscles affected. As the disease gets worse, more muscle groups develop problems.
Life expectancy of an ALS patient averages about two to five years from the time of diagnosis.

45. Amyotrophic lateral sclerosis (ALS) is caused by the degeneration and death of motor neurons in the spinal cord and brain. These neurons convey electrical messages from the brain to the muscles to stimulate movement in the arms, legs, trunk, neck, and head. As motor neurons degenerate, the muscles are weakened and cannot move as effectively, leading to muscle wasting.

46.
Fans, for the past two weeks you have been reading about the bad break. Today I consider myself the luckiest man on the face of this earth. That I might have been given a bad break, but I have an awful lot to live for. Thank you.
His record for most career grand slam home runs (23) still stands today (Alex Rodriguez has 22, Manny Ramirez has 21)

47. Disorders of the Muscular System
3. Myasthenia gravis: is caused by a defect in the transmission of nerve impulses to muscles.
Its a disease in which the immune system attacks the body's own tissues ("autoimmune" disease);
Causes a weakness of voluntary muscles without pain that gets worse with repeated or sustained use of the muscle (fatigued muscle weakness).
In two thirds of patients with MG, the first muscles to be affected are those controlling eye movements (causing double vision) and those holding the eyelids up (causing drooping of the eyelids).
There are medications to treat the disorder. It is not fatal.

48. 4. Chronic Fatigue Syndrome: Symptoms of chronic fatigue syndrome include loss of memory, difficulty concentrating, fatigue, random muscle pain, headaches, unrefreshing sleep and sore throats.
5. Fibromyalgia: results in widespread pain throughout every muscle in a person's body. Approximately 2% of the entire US population is affected by fibromyalgia. Symptoms of fibromyalgia include joint tenderness, fatigue problems, and sleep disturbances. No cure.

49. 6. Cerebral Palsy:
Cerebral palsy is condition that can involve brain and nervous system functions such as movement, learning, hearing, seeing, and thinking.
There are several different types of cerebral palsy.
Cerebral palsy is caused by injuries or abnormalities of the brain.
Most of these problems occur as the baby grows in the womb, but they can happen at any time during the first 2 years of life, while the baby's brain is still developing.

50. Botulism & Botox
Difficulty swallowing or speaking
Facial weakness on both sides of the face
Blurred vision
Drooping eyelids
Trouble breathing
Nausea, vomiting and abdominal cramps (only in food-borne botulism)
Paralysis
Botulism is a rare but serious condition caused by toxins from bacteria called Clostridium botulinum.
can be fatal
A weakened botulinum toxin (BOTOX) has been used to reduce facial wrinkles by paralyzing muscles beneath the skin, and for medical conditions, such as eyelid spasms and severe underarm sweating.

51. Botulism: What is this toxin. http://video. google. com/videosearch
Botulism: Cerebral Palsy treatment and Botox

52. Poisons vs. Venom
Terms are often used interchangeably, but they actually have very different meanings.
It is the delivery method that distinguishes one from the other.
Poison is absorbed or ingested; Ex. Toxin in skin or organs. (frogs, puffer fish, poison ivy)
Venom is always injected. Ex. Stab with tails. Slash with spines. Pierce with fangs. Spike with spurs. Shoot with harpoons. Chew with teeth. (snakes, spiders, bees)

53. Poisons (venom) Effects of snake venom:
Stiletto Snake bite:
Part 1 : Envenomation
Part 2:
Part 3: surgery
Part 3 automatically plays first so select Part 1
Effects of snake venom:
Part 3: Rattlesnake Compartment Syndrome
Part 2:Symptoms of the Bite
Part 1: Bitten By a Rattler

54. Two Types of Venom and What They Do To The Body
1. Neurotoxin acts on the victim's nervous system, causing excitation (cramps, vomiting, convulsions) or depression (paralysis, respiratory or cardiac depression or arrest).
Black Widow Spider
Cobra
Coral Snakes
Gila monster
Puffer fish
Short-tailed shrew
Kraits

55. Two Types of Venom and What They Do To The Body
2. Hemotoxin ("blood poison") breaks down the victim's tissues, usually by an acid or a toxin that prevents or causes blood clotting, or destroys red or white blood cells. Venom usually contains both types, but one dominates.
scorpion
Copperhead
Rattlesnakes
Water Moccasin/Cottonmouth

56. You are 9X more likely to die by lightening strike than getting bit by a venomous snake.

58. Hey You!
Label my muscles!

61. Steroids anyone?

62. Steroid use: 15minutes (some bad lang.)
Part 3:
Part 4:
Tyra: Greg Today:

63. Muscle System Test
3 types of muscles: chara. of each one, and ID a picture.(matching description with muscle type)
Four functions of skeletal muscles.
Produce movement
Maintain posture
Stabilize joints
Generate heat
Basic Microscopic Anatomy/sliding filament theory. Label muscle cell.
7 ways to name muscles & ex of each.
Name the main anterior and posterior muscles.
Disorders/diseases (M.D., cerebral palsy, ALS, myasthenia gravis, botulism, snake venom) : treatment: Botox

65. The anatomy of a sarcomere
The entire array of thick and thin filaments between the Z disks is called a sarcomere.
The thick filaments produce the dark A band.
The thin filaments extend in each direction from the Z disk. Where they do not overlap the thick filaments, they create the light I band.
The H zone is that portion of the A band where the thick and thin filaments do not overlap.
The M line runs through the exact center of the sarcomere. Molecules of the giant protein, titin, extend from the M line to the Z disk. One of its functions is to provide a scaffold for the assembly of a precise number of myosin molecules in the thick filament (294 in one case). It may also dictate the number of actin molecules in the thin filaments.
Shortening of the sarcomeres in a myofibril produces the shortening of the myofibril and, in turn, of the muscle fiber of which it is a part.
[This electron micrograph of a single sarcomere was kindly provided by Dr. H. E. Huxley.]

66. Actin & Myosin

67. Actin & Myosin

68. Sliding Filament Theory1. 2.

69. 7 stages of the Sliding Filament Theory
First Stage: The first stage is when the impulse gets to the unit. The impulse travels along the axon and enters the muscle through the neuromuscular junction. This causes full two to regulate and calcium channels in the axon membrane to then open. Calcium ions come from extra cellular fluid and move into the axon terminal causing synaptic vessels to fuse with pre synaptic membranes. This causes the release of acetylcholine (a substance that works as a transmitter) within the synaptic cleft. As acetylcholine is released it defuses across the gap and attaches itself to the receptors along the sarcolemma and spreads along the muscle fiber. Second Stage: The second stage is for the impulse spreads along the sarcolemma. The action potential spreads quickly along the sarcolemma once it has been generated. This action continues to move deep inside the muscle fiber down to the T tubules and the action potential triggers the release of calcium ions from the sarcoplasmic reticulum. Third Stage: During the third stage calcium is released from the sarcoplasmic reticulum and actin sites are activated. Calcium ions once released begin binding to Troponin. Tropomyosin blocking the binding of actin is what causes the chain of events that lead to muscle contraction. As calcium ions bind to the Troponin it changes shape which removes the blocking action of Tropomyosin (thin strands of protein that are wrapped around the actin filaments). Actin active sites are then exposed and allow myosin heads to attach to the site. Fourth Stage: The fourth stage then begins in which myosin heads attach to actin and form cross bridges, ATP is also broken down during this stage. Myosin binds at this point to the exposed binding sites and through the sliding filament mechanism the muscles contract. Fifth Stage: During the fifth stage the myosin head pulls the Actin filament and ADP and inorganic Phosphate are released. ATP binding allows the myosin to detach and ATP hydrolysis occurs during this time. This recharges the myosin head and then the series starts over again. Stage Six: Cross bridges detach while new ATP molecules are attaching to the myosin head while the myosin head is in the low-energy configuration. Cross bridge detachment occurs while new ATP attaches itself to the myosin head. New ATP attaches itself to the myosin head during this process. Stage Seven: During stage seven the ATP is broken down and used as energy for the other areas including new cross bridge formation. Then the final stage (stage 8) begins and a drop in stimulus causes the calcium concentrate and this decreases the muscle relaxation.
Read more:

70. Resting and Action Potential
Neurons send messages electrochemically. This means that chemicals cause an electrical signal.
The important ions in the nervous system are sodium and potassium (both have 1 positive charge, +), calcium (has 2 positive charges, ++) and chloride (has a negative charge, -).
Resting Membrane Potential
When a neuron is not sending a signal, it is "at rest.“
Action Potential
An action potential occurs when a neuron sends information down an axon, away from the cell body. Neuroscientists use other words, such as a "spike" or an "impulse" for the action potential.
The action potential is an explosion of electrical activity that is created by some event (a stimulus).
There are no big or small action potentials in one nerve cell - all action potentials are the same size. Therefore, the neuron either does not reach the threshold or a full action potential is fired - this is the "ALL OR NONE" principle.
This is in reference to an individual muscle cell not the whole muscle therefore there can be a graded response in the muscle contraction.

72. Neuromuscular Junction
A skeletal muscle cannot contact unless stimulated by a motor nerve.
This junction between a nerve fiber (axon) and muscle cell is called a neuromuscular junction.
Watch it using flash player:

73. Acetylcholine
When acetylcholine is released from an axon terminal, it moves across the synaptic cleft to bind to a receptor on the other side of the synapse (on the post-synaptic membrane).
In the peripheral nervous system, acetylcholine is located at the "neuromuscular junction" where it acts to control muscular contraction.

74. Extra Credit 1. How does adrenaline make you stronger?
2. Muscles are usually in antagonistic pairs. What does that mean and give an example of a pair?