human anatomy chapter 9
1. Many of our physiological processes
2. Virtually all our dynamic interactions with the environment
humans rely on muscles for (2)
1. skeletal muscle
2. cardiac muscle
3. smooth muscle
three types of muscle tissue
1. produce skeletal movement
2. maintain posture and body position
3. support soft tissue
4. regulate entering and exiting of material
5. maintain body temp.
1. skeletal muscle functions
1. Pushes blood through arteries and veins
2. Rhythmic contractions
2. cardiac muscle functions
1. Pushes fluids and solids along the digestive tract, for example
2. Involuntary contraction
3. Smooth muscle functions
1. excitability: The ability to respond to stimuli
2. contractility: The ability to shorten and exert a pull or tension
3. extensibility: The ability to continue to contract over a range of resting lengths
4. Elasticity: The ability to rebound toward its original length
Four basic properties that all muscle tissues share
1. Overall organization of muscles
2. Connective tissue associated with muscles
3. Nerves associated with muscles
4. Blood vessels associated with muscles
Gross Anatomy of skeletal muscles is the study of... (4)
1. Myofibrils
2. Myofilaments
3. Sarcomeres
Microscpoic anatomy of skeletal muscles is the study of... (3)
1. Epimysium
2. Perimysium
3. Endomysium
Gross Anatomy
Connective tissue of muscle
1. dense tissue that surrounds the entire muscle
2. dense tissue that divides the muscle into parallel compartments of fascicles
3. dense tissue that surrounds individual muscle fibers
Gross Anatomy
Connective tissue of muscle
1. Epimysium
2. Perimysium
3. Endomysium
1. skeletal muscle (organ)
2. Muscle Fassicle (bundle of cells)
3. Muscle Fiber
4. Epimysium
5. Perimysium
6. Endomysium
1. Tenconds: connect a muscle to a bone
2. Aponeuroses: Connect a muscle to a muscle
Connective tissue of muscles
1. Epimysium
2. Perimysium
3. Endomysium
What converge to form tendons?(3)
1. Innervate the muscle
2. Chemical communication b/w a nerve and a muscle
3. "connected" to the muscle via the motor end plate---> this is the meuromuscular junction
Gross Anatomy
Nerves and Blood Vessels
1. Nerves....
2. There is a...
3. the nerve is...
4. Inntervate the endomysium of the muscle
5. branch to form coiled networks to accommodate flexion and extension of the muscle
Gross Anatomy
Nerves and Blood Vessels
4. Blood vessels...
5. they then...
1. neuromuscular synapse
2. skeletal muscle fibers
3. Axons
1. Membrane that surrounds the muscle cell
2. The cytosol of the muscle cell
3. A. Can be 30–40 cm in length
B. Multinucleated (each muscle cell has hundreds of nuclei)
C. Nuclei are located just deep to the sarcolemma
Microanatomy of skeletal muscle fibers
1. Sarcolemma
2. Sarcoplasm
3. muscle fiber(3)
1. myofibrils
2. the contraction of muscles
3. the sarcolemma at each end of the muscle cell
4. sarcoplasmic reticculum
1. the sarcoplasm contains...
2. myofibrisl are responsible for...
3. myofibrils are attached to...
4. surrounding each myofibril is the...
1. myofilaments
2. A. Actin
B. Myosin
1. Myofibrils are made of...
2. (these include...
1. (Thick filament)
2. Thin Filament
3. repeating units called sarcomeres
4. parallel to the long axis of the cell
Sarcomere Organization
1. myosin
2. actin
3. both are arranged in...
4. all the myofilaments are arranged....
1. Main functioning unit of muscle fibers
2. 10,000 per myofibril
3. overlapping actin and myosin
4. the striations that gibe the skeletal muscle its identifiable characteristic
Sarcomere Organization
1. is...
2. approximately...
3. consists of...
4. this over lapping creates...
A. Z line (Z disc)
B. I band
C. A band (overlapping A bands create striations)
D. H band
E. M line
Sarcomere Organization
5. each Sarcomere consists of... (5)
1. I band 4. H band
2. A band 5. thick filament
3. Z line 6. thin filament
A. skeletal muscles B. Muscle fascicles
C. muscle fibers D. myofibrils
E. sarcomeres F. myofilaments
G. actin H. myosin
Levels of organization
__A__ consists of __B__ -> Consists of __C__ -> consists of __D__ -> consists of __E__ -> consists of __F__ -> are made of __G__ and __H__
1. skeletal mmuscle 4. myofibril
2. muscle fascicles 5. sarcomere
3. muscle fibers
1. G Actin molecues
2. Active site
3. Myosin Cross- bridges
4. tropomyosin
5. troponin
Actin
1. twisted filament consisting of...
2. Each G actin molecule has an...
3. ____ bind to the active site on actin
4. ____: a protein that covers the the binding sites when the musle is relaxed
5. ___: holds tropomyosin in position
A. sarcomere B. H bank
c. myofibril D. Z line
E. M line F. Actin
G. Z line H. Titin
I. troponin J. Active Site
K. Tropomyosin L. G actinmolecules
1. an elongated tail and a globular head (cross-bridges)
2. stationary molecule
A. M line
B. Titin connecting to the Z lines
Myosin
1. myosin filaments consist of...
2. Myosin is a ____. it is held in place by:
A. protein forming the...
B. a Core of...
1. shortens
2. interactions between thick and thin filaments within the sarcomere
3. the presence of calcium ions
4. ATP
5. slide toward each other
6. sliding filament theory
Muscle contraction
1. A contracting muscle ____ in length
2. Contraction is caused by
3. Contraction is triggered by
4. Muscle contraction requires the presence
5. When a muscle contracts, actin filaments
6. This sliding action is called the
1. get smaller
2. larger
3. closer together
4. remains constant throughout the contraction
The sliding filament theory
Upon contraction:
1. The H band and I band
2. The zone of overlap gets
3. The Z lines move
4. The width of the A band
1. impulse
2. acetylcholine is released
3. release its stored calcium ions
4. bind to troponin
Events leading to muscle conraction
1. an ___travels down the axon of a nerve
2. _____from the end of the axon at the motor end plate
3. This ultimately causes the sarcoplasmic reticulum to
4. Calcium ions
5. rotation of the troponin- tropomyosin complex
6. exposes the binding sites on the actin myofilament
7. myosin heads
8. cross-bridge pivot
9. muscle becomes shorter
Events leading to muscle contraction
5. This binding action causes a
6. This rotation
7. ____extend and bind to the binding sites on actin
8. the _____ thus sliding the actinmyofilament
9. As the actin myofilaments are pulled toward each other, the
1. A motor neuron controlling two or three musclefibers
A. the control over the eye muscles
2. A motor neuron controlling perhaps 2000 muscle fibers
A. the control over the leg muscles
Motor units and Muscle control
Motor units
1. Precise control (example)
2. Less precise control (example)
1. The frequency of stimulation
2. The number of motor units involved
Motor units and muscle control
Muscle tension Depends on
1. A. The tension of a muscle when it is relaxed
B. Stabilizes the position of bones and joints
2. These are specialized muscle cells that are monitored by sensory nerves
Motor units and muscle control
1. Muscle tone
2. Muscle spindles
The net effect is an enlargement of the muscle
Hypertrophy
Discontinued use causes decreased muscle size and muscle tone
Muscle Atrophy
1. Fast Fibers (white fibers)associated with eye muscles
2. Intermediate Fibers (pink Fibers)
3. Slow fibers (red fibers)associated with leg muscles
Three major types of skeletal muscle fibers
1. Large in diameter
2. Large glycogen reserves
3. Relatively few mitochondria
4. Muscles contract using anaerobic metabolism
5. Fatigue easily
6. Can contract in 0.01 second or less after stimulation
7. Produce powerful contractions
features of fast fibers (7)
1. Half the diameter of fast fibers
2. Take three times longer to contract after stimulation
3. Can contract for extended periods of time
4. Contain abundant myoglobin (creates the red color)
5. Muscles contract using aerobic metabolism
6. Have a large network of capillaries
Features of slow fibers (6)
1. Similar to fast fibers
A. Have low myoglobin content
B. Have high glycolytic enzyme concentration
C. Contract using anaerobic metabolism
2. Similar to slow fibers
A. Have lots of mitochondria
B. Have a greater capillary supply
C. Resist fatigue
Features of intermediate fibers
A. High density associated with eye and hand muscles
B. Sprinters have a high concentration of fast fibers
C. Repeated intense workouts increase the fast fibers
Distribution of fast, slow, and intermediatefibers
1. Fast fibers (3)
A. None are associated with the eyes or hands
B. Found in high density in the back and leg muscles
C. Marathon runners have a high amount
D. Training for long distance running increases the proportion of intermediate fibers
Distribution of fast, slow, and intermediatefibers
2. Slow and intermediate fibers (4)
1. Parallel muscle fibers
2. Convergent muscle fibers
3. Pennate muscle fibers
4. Unipennate muscle fibers
5. Bipennate muscle fibers
6. Multipennate muscle fibers
7. Circular muscle fibers
muscle classifications based on shape or arrangement of fibers (7)
Muscle fascicles are parallel to the longitudinal axis
Biceps brachii and rectus abdominis
1. PArallel Muscle fibers
Examples
A. Parallel muscle
B. PArallel muscle
Muscle fibers form a broad area but come together at a common point
Pectoralis major
2. Convergent Muscle Fibers
examples
D. Convergent muscle
3. Muscle fibers form an oblique angle to the tendon of the muscle
4. All the muscle fibers are on the same side of the tendon
Extensor digitorum
3. Pennate Muscle Fibers
4. Unipennate muscle fibers
Example
E. Unipennate muscle
5. Muscle fibers are on both sides of the tendon
Rectus Femoris
5. Bipennate muscle fiber
example
F. Bipennate Muscle
6. The tendon branches within the muscle
Deltoid muscle
6. Multipennate muscle fibers
example
G. multipennate muscle
7. Muscle fibers form concentric rings
A. Sphincter muscles
B. Orbicularis oris and orbicularis oculi
7. Circular muscle fibers
A. AKA
B. examples
H. circular muscle
1. Point of muscle attachment that remains stationary
2. Point of muscle attachment that is movable
3. The function of the muscle upon contraction
Muscle Terminology
1. Origin
2. Insertion
3. Action
1. Prime Movers (agonists)
2. Antagonists
3. Synergists
4. Fixators
Muscles can be grouped according to their primary actions into four types:
1. Responsible for producing a particular movement
2. Actions oppose the action of the agonist
3. Assist the prime mover in performing an action
4. Agonist and antagonist muscles contracting at the same time to stabilize a joint
1. Prime Movers (agonists)
2. Antagonists
3. Synergists
4. Fixators
1. Biceps brachii – flexes the lower arm
2. Triceps brachii – extends the lower arm
3. Latissimus dorsi and teres major – contract to move the arm medially over the posterior body
4. Flexor and extensor muscles contract at the same time to stabilize an outstretched hand
1. Prime Movers (agonists) examples
2. Antagonists examples
3. Synergists examples
4. Fixators examples
1. Specific body regions or location
2. Shape of the muscle
3. Orientation of the muscle fibers
4. Specific or unusual features
5. Its origin and insertion points
6. Primary function
7. References to occupational or habitual action
Muscles can be named for
1. associated with the brachium of the arm
2. associated with the anterior tibia
Specific body regions or locations
1. brachialis
2. tibialis anterior
1. trapezoid shape
2. triangular shape
Shape of the muscle
1. trapezius
2. Deltoid
1. straight muscle of the leg
2. muscle on outside that is oriented with the fibers at an angle
Orientation of the muscle fibers
1. Rectus femoris
2. External oblique
1. two origins
2. long, big, rounded muscle
Specific or unusual features
1. Biceps brachii
2. Teres Major
1. points of attachment are sternum, clavicle, and mastoid process
2. points of attachment are chin and tongue
Origin and insertion points
1. Sternocleidomastoid
2. Genioglossus
1. a muscle that is near the radius and flexes the wrist.
2. a long muscle that adducts the leg
Primary functions
1. Flexor carpi radialis
2. Adductor longus
1. the buccinator area moves when playing a trumpet
2. derived from the Latin term (sartor), which is in reference to “tailors.” Tailors used to cross their legs to form a table when sewing material
References to occupational or habitual actions
1. Buccinator
2. Sartorius
1. action
2. Lever (a bone)
3. Fulcrum (joint)
4. Force acting in the opposite direction
Levers and Pulleys: A Systems Design for Movement
1. most of the time, upon contraction, a muscle causes...
2. this action is applied to a ____
3. This Lever moves on a fixed point called the ___
4. The action of the lever is apposed by a...
1. First class
2. second class
3. third class
There are three classes of levers
1. The fulcrum (joint) lies between the applied force and the resistance force (opposed force)
tilting the head forward and backward
classes of levers
1. first class
example
2. The resistance is located between the applied force and the fulcrum (joint)
standing on your tip toes
classes of levers
2. second class
example
3. The force is applied between the resistance and fulcrum (joint)
flexing the lower arm
classes of levers
3. third class
example
1. loop around a bony projection
2. pulley
3. lateral malleolus and trochlea of the eye
Levers and Pulleys: A Systems Design for Movement
1. sometimes, a tendon may...
2. this bony projection could be called...
3. example
1. Skeletal muscle fibers become smaller in diameter
2. There is a decrease in the number of myofibrils
3. Contain less glycogen reserves
4. Contain less myoglobin
5. There is a decrease in myosatellite cells
6. There is an increase in fibrous connective tissue
Changes that occur in muscles as we age
(6)
1. decrease in strength and endurance
2. Muscles fatigue rapidly
changes in muscles as we age
4. Contain less myoglobin results in(2)
1. Results in fibrosis
2. The ability to recover from muscular injuries decreases
changes occur in muscles as we age
6. There is an increase in fibrous connective tissue
A. Results in (2)