skeletal muscle revie · 2013-01-24 · when the muscle contracts it will shorten the distance...
TRANSCRIPT
![Page 1: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/1.jpg)
Muscular System Anatomy of Muscle Fibrils Physiology of Muscle Contraction
![Page 2: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/2.jpg)
websites
• http://www.biologycorner.com/anatomy/chap8.html
![Page 3: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/3.jpg)
Did you know that ?
- More than 50% of body weight is muscle !
- Muscle is made up of proteins and water
![Page 4: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/4.jpg)
![Page 5: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/5.jpg)
The Muscular System
• Muscles are responsible for all movement of the body
• There are three basic types of muscle • Skeletal (Striated or Voluntary) • Cardiac (Heart) • Smooth (Involuntary)
![Page 6: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/6.jpg)
3 Types of Muscles
![Page 7: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/7.jpg)
Info About Muscles • Only body tissue able
to contract • Create movement by
flexing and extending joints
• Body energy converters (many muscle cells contain many mitochondria)
![Page 8: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/8.jpg)
Functions of Muscles
• Produce external movement • Maintain posture – hold body still or in a
particular position • Stabilize joints
• Movement of substances inside the body – cardiac and smooth (visceral) muscles transport blood and food
• Generate heat by contractions – High metabolic rate of contracting produces lots of waste heat; small contractions to maintain body temperature
![Page 9: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/9.jpg)
Three types of muscle Skeletal Cardiac Smooth
![Page 10: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/10.jpg)
Muscle Terms
All muscles share some terminology • Prefixes myo and mys refer to
muscle • Prefix sarco refers to flesh
![Page 11: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/11.jpg)
Classification of Muscle Skeletal Cardiac Smooth
Limbs Heart Viscera Movement Heartbeat
Move food & and other substances through the body
Striated Multi- nucleated Fibers in bundles
Striated and Branched Uni-nucleated Lots of mitochondria
Not striated Uni-nucleated Fibers in sheets
Voluntary Contracts in short, strong bursts
Involuntary All fibers contract at the same time
Involuntary Contracts slowly, but steadily
![Page 12: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/12.jpg)
Skeletal Muscle • Also called Striated Muscle • Always connect to skeleton in at least one place
• Most attached to two bones by a tendon
• Act independently of neighboring muscle fibers
![Page 13: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/13.jpg)
Skeletal or Striated Muscle
• Striated - have stripes, banding • Multi-nucleated - cells have more than
one nucleus • Voluntary - subject to conscious
control, CNS • Long cylindrical fibers are arranged in
bundles
![Page 14: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/14.jpg)
Muscles move Bones
• Muscles move by shortening their length, pulling on tendons, and moving bones closer to each other. • Tendons – strong collagen fibers
• One bone is pulled toward the other bone, which remains stationary.
![Page 15: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/15.jpg)
How are Muscles Attached to Bone?
• Muscle connected to stationary bone by tendons at the Origin. The basis for the action.
• Muscle connected to moving bone by tendons at the Insertion. The effects of the action.
• Muscles are always attached to at least 2 points
• Movement is attained due to a muscle moving an attached bone
![Page 16: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/16.jpg)
Muscle Attachments
Origin
Insertion
![Page 17: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/17.jpg)
Naming Muscles
• Location •Origin and Insertion •Number of Origins •Shape, Size and Direction •Function
![Page 18: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/18.jpg)
Three types of Connective Tissue
The layers of connective tissue are the cement that holds the muscle cells and bundles together
• Epimysium – surrounds the whole muscle • Perimysium – surrounds the Fascicle
(individual bundles of muscle cells) • Endomysium – surrounds the Muscle
Fiber (Muscle Cell)
![Page 19: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/19.jpg)
Bone to Muscle Fiber / cell
![Page 20: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/20.jpg)
Progression of Anatomy
![Page 21: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/21.jpg)
Structure of skeletal muscle
• Each Muscle Cell or Fiber is long and cylindrical
• 50-60 mm in diameter, and up to 10 cm long (length is greater than width)
• The contractile elements of skeletal muscle cells are Myofibrils
• Sarcolemma – special cell membrane that conducts electrochemical signals
![Page 22: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/22.jpg)
![Page 23: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/23.jpg)
Sarcotubular System
Vesicles and Tubules that surround the Muscle Fiber (cell)
• T-System or Tubules – connect to sarcolemma and transmits the nerve impulse to the middle of the cell and all the thousands of myofibrils that make up the muscle cell
• Sarcoplasmic Reticulum - forms a curtain around each myofibril and a storehouse of the calcium ions (Ca + 2) that are part of the contraction mechanism
![Page 24: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/24.jpg)
Sarcomere
![Page 25: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/25.jpg)
Dark and Light Bands
Myofibrils – muscle fiber structure; contractile elements
A Bands - Dark and thick – Myosin H Band (zone) – darker area in the middle of the A Band
I Bands – Light and thin – Actin Z Line (band, disc) – narrow, dark band in the central region of the I Band Sarcomere – area between two Z Lines – functional unit of muscle fiber
![Page 26: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/26.jpg)
![Page 27: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/27.jpg)
3 Factors cause a Muscle Contraction
1. Neuroelectrical Factors – Nerve impulse causes Potassium ions (K +) and Sodium ions (Na¯ ) to switch places across the cell membrane and create an Action Potential that travels along the T-System.
2. Chemical Interactions – Actin unites with Myosin to form Actomyosin.
3. Energy Sources – ATP
![Page 28: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/28.jpg)
Where Does the Energy Come From? • This all happens in the Mitochondria
• Energy is stored in the muscles in the form of ATP
• ATP comes from the breakdown of glucose during Cellular Respiration
![Page 29: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/29.jpg)
Neurotransmitters
• Acetylcholine – released from synaptic vesicles, stimulates a muscle impulse
• Cholinesterase – enzyme that stops action of acetylcholine
![Page 30: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/30.jpg)
Steps in a Contraction 1
• More Potassium ions inside the cell than outside. More Sodium ions outside the cell than inside. Inside the cell is negatively charged and outside is positively charged – Resting Potential
• At the neuromuscular junction (end of the axon), a nerve impulse causes release of acetylcholine from the synaptic vesicles into the synaptic cleft.
• Acetylcholine diffuses across the neuromuscular junction and binds to receptors on the sarcolemma (muscle cell membrane).
![Page 31: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/31.jpg)
Action Potential
![Page 32: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/32.jpg)
Steps in a Contraction 2
• Impulse spreads across sarcolemma and increases the permeability to K+ ions (depolarization) - the potassium ions rush outside the cell and the sodium ions rush inside the cell. This creates an electrical potential - and the Action Potential is generated.
• Action Potential travels by way of the T-Tubules to
all the cells and causes the Sarcoplasmic Reticulum to release Calcium ions that diffuse into the sarcoplasm.
![Page 33: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/33.jpg)
![Page 34: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/34.jpg)
Steps in a Contraction 3
• The Calcium ion concentration at the myofilaments increases and negates the troponin and tropomyosin which keeps the filaments apart. This causes the formation of cross bridges between the actin and myosin filaments and they slide between each other and make Actomyosin. The Z Lines move together.
• Contraction – the formation of the Actomyosin
shortens the myofibril which shortens the muscle fibers which shortens the muscles
![Page 35: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/35.jpg)
Actin and Myocin
![Page 36: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/36.jpg)
Steps in a Contraction 4
• Sodium –Potassium Pump operation restores the Na and K distribution to the resting potential. Calcium ions are actively reabsorbed (Calcium Pump using ATP) into the Sarcoplasmic Reticulum and the concentration in the myofilaments decreases.
• Contraction stops. The Z Lines move apart. The muscle cell relaxes and lengthens. Enzyme Cholinesterase stops action of the Acetylcholine.
![Page 37: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/37.jpg)
Too Little Oxygen & ATP Too Much CO₂
• Muscle Fatigue - a muscle is tired and unable to contract because of lack of oxygen, energy (ATP) and too many waste products.
• Oxygen Debt - the amount of oxygen that the body needs to restore muscle cells to resting state. You feel out of breath!
![Page 38: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/38.jpg)
Contraction Physiology
• Motor Unit – one motor neuron and the muscle fibers (cells) that it sends impulses to; they all contract together • Average 150 muscle cells • 200 muscle cells for gross movement (hand) • 10 muscle cells for fine movement (eye)
• Muscle Cells have four properties: • Excitability – stimulated by a nerve cell (neuron) • Conductivity – response can travel throughout cells • Contractility – the response to the stimulus • Elasticity – return to original shape after contraction
![Page 39: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/39.jpg)
Contractions
Contraction Cycle - Latent Period to Contraction Period (Shortening of fibers) to Relaxation Period Strength of contraction depends on:
• Number of Motor Units sending signals • Strength of stimulus • Duration of stimulus • Speed of application • Weight of the load (table vs. coffee cup) • Temperature of the body (98.6⁰)
![Page 40: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/40.jpg)
All or None Law
A stimulus that elicits a response will produce a maximum contraction. The contraction occurs or it does not.
![Page 41: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/41.jpg)
Muscle Twitch
Single nerve impulse of a motor neuron will cause a motor unit to contract briefly before relaxing
• A single brief small contraction • Not a normal muscle function
![Page 42: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/42.jpg)
Muscle Tetanus
Motor neuron provides many nerve impulses in rapid succession, the muscle has a complete and lasting contraction.
• One contraction immediately followed by another • Effects are compounded • Remains in tetanus until the nerve signal slows or
the muscle too fatigued to continue • Muscle never completely returns to a relaxed
state
![Page 43: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/43.jpg)
Muscle Tone
A natural condition of in which a muscle stays partially contracted at all times.
• Some muscle cells will always be contracting while other muscle cells are at rest.
• Maintain body posture without tiring • Slight and steady pull on attached bones • Pressure on abdominal contents • Blood pressure in arteries and veins • Assists in digestion in stomach and intestines • Prevents damage to muscle and joints from sudden
movements
![Page 44: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/44.jpg)
Two types of Contractions
• Isotonic Contraction – tone or tension remains the same; the muscles become shorter and thicker; lifting a weight
• Isometric Contraction – muscles remain at a constant length while the tension against the muscle increases; push against a wall or lift a large rock
![Page 45: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/45.jpg)
Exercise and Muscles
• Isotonic - muscles shorten and movement occurs ( most normal exercise)
• Isometric - tension in muscles increases, no movement occurs (pushing one hand against the other); help develop tone or firmness in muscles
![Page 46: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/46.jpg)
More or Less
• Hypertrophy – increase in size due to repeated forceful contractions (exercise); 75% maximum effort
• Atrophy – disuse or very low intensity use causes muscle to shrink – fibers shorten and replaced with fat and connective tissue (CT).
![Page 47: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/47.jpg)
Smooth Muscle
• No striations • Spindle shaped • Single nucleus • Involuntary - no conscious
control, ANS • Found mainly in the walls of hollow
organs
![Page 48: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/48.jpg)
Location of Smooth Muscle
• Lines walls of viscera • Hollow Structures
• Intestines • Blood Vessels • Urinary Bladder
![Page 49: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/49.jpg)
Hollow Organs
![Page 50: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/50.jpg)
![Page 51: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/51.jpg)
![Page 52: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/52.jpg)
Intestines
• 2-Layer Arrangement • longitudinal and
circular layers • Alternate contraction
of circular & longitudinal muscle in the intestine leads to peristalsis
![Page 53: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/53.jpg)
Structure of smooth muscle
• Elongated Spindle shaped
uni-nucleated cells • Striations not observed • Actin and myosin filaments are
present (protein fibers) but not as regularly arranged
![Page 54: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/54.jpg)
Physiology of Smooth Muscle
• Slower and more rhythmic contractions
• Greater extensibility of the muscle • Slow wave of contraction over the
entire muscle mass
![Page 55: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/55.jpg)
![Page 56: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/56.jpg)
Cardiac Muscle
• Striations – very strong cells • Branching or y-shaped cells • Involuntary – ANS – autorhythmic • Uni-nucleated • Found only in the heart – responsible for
pumping blood • Cells connected by Intercalculated Discs
that spread signals quickly from cell to cell to beat as a unit
![Page 57: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/57.jpg)
Cardiac muscle
• Main muscle of heart • Pumping mass of heart • Critical in humans • Heart muscle cells
behave as one unit • Heart always contracts
to full extent
![Page 58: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/58.jpg)
Structure of cardiac muscle • Cardiac muscle cells (fibers) are short,
branched and interconnected • Cells are striated & usually have 1
nucleus • Adjacent cardiac cells are joined via
electrical synapses (gap junctions) • These gap junctions appear as dark
lines and are called Intercalated Discs
![Page 59: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/59.jpg)
Contractions of Cardiac Muscle
• Rapid rhythm of contractions • Impulse – contract – relax - another
impulse – contract… • About 75 contractions per minute • Fibrillation – rapid uncontrolled
contractions of individual cells; blood is not pumped properly
![Page 60: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/60.jpg)
Muscle Control Type of muscle
Nervous control
Type of control
Example
Skeletal Skeletal Controlled by CNS
Voluntary Lifting a glass
Cardiac Regulated by ANS
Involuntary Heart beating
Smooth Controlled by ANS
Involuntary Peristalsis
![Page 61: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/61.jpg)
END OF ANATOMY AND PHYSIOLOGY
![Page 62: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/62.jpg)
Flexion
Types of Musculo-Skeletal Movement
![Page 63: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/63.jpg)
Extension
![Page 64: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/64.jpg)
Hyperextension
![Page 65: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/65.jpg)
Abduction, Adduction & Circumduction
![Page 66: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/66.jpg)
Rotation
![Page 67: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/67.jpg)
More Types of Movement……
• Inversion- turn sole of foot medially • Eversion- turn sole of foot laterally • Pronation- palm facing down • Supination- palm facing up • Opposition- thumb touches tips of fingers on the same
hand
![Page 68: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/68.jpg)
The Skeletal Muscles There are about 650 muscles in the human body. They enable us to move, maintain posture and generate heat. In this section we will only study a sample of the major muscles.
![Page 69: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/69.jpg)
Sternocleidomastoideus Flexes and Rotates Head
![Page 70: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/70.jpg)
Masseter Elevate Mandible
![Page 71: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/71.jpg)
Temporalis Elevate & Retract Mandible
![Page 72: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/72.jpg)
Trapezius Extend Head, Adduct, Elevate or Depress Scapula
![Page 73: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/73.jpg)
Latissimus Dorsi Extend, Adduct & Rotate Arm Medially
![Page 74: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/74.jpg)
Deltoid Abduct, Flex & Extend Arm
![Page 75: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/75.jpg)
Pectoralis Major Flexes, adducts & rotates arm medially
![Page 76: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/76.jpg)
Biceps Brachii Flexes Elbow Joint
![Page 77: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/77.jpg)
Triceps Brachii Extend Elbow Joint
![Page 78: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/78.jpg)
Rectus Abdominus Flexes Abdomen
![Page 79: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/79.jpg)
External Oblique Compress Abdomen
![Page 80: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/80.jpg)
External Intercostals Elevate ribs
![Page 81: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/81.jpg)
Internal Intercostals Depress ribs
![Page 82: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/82.jpg)
Forearm Muscles
• Flexor carpi—Flexes wrist • Extensor carpi—Extends wrist • Flexor digitorum—Flexes fingers • Extensor digitorum—Extends fingers • Pronator—Pronates • Supinator—Supinates
![Page 83: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/83.jpg)
Diaphragm Inspiration
![Page 84: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/84.jpg)
Gluteus Maximus Extends & Rotates Thigh Laterally
![Page 85: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/85.jpg)
Rectus Femoris Flexes Thigh, Extends Lower Leg
![Page 86: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/86.jpg)
Gracilis Adducts and Flexes Thigh
![Page 87: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/87.jpg)
Sartorius Flexes Thigh, & Rotates Thigh Laterally
![Page 88: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/88.jpg)
Biceps Femoris Extends Thigh & Flexes Lower Leg
![Page 89: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/89.jpg)
Gastrocnemius Plantar Flexes Foot & Flex Lower Leg
![Page 90: Skeletal Muscle Revie · 2013-01-24 · When the muscle contracts it will shorten the distance betwee\൮ the origin and insertion. The head will move when this muscle contracts](https://reader033.vdocument.in/reader033/viewer/2022041615/5e3b396aa504fa2b08324bf0/html5/thumbnails/90.jpg)
Tibialis Anterior Dorsiflexes and Inverts Foot