Muscles Flashcards
(45 cards)
1
Q
Cardiac Muscle Characteristics
A
Where: Heart Appearance: Striated Shape: Branching Y Action: Involuntary Nucleus: Uni-Bi Rhythmic: Rhythmic Intercalated Discs: Yes Speed of Contraction: Slow
2
Q
Smooth Muscle Characteristics
A
Where: Visceral (Internal Organs) Appearance: Non-striated Shape: Tapered point Action: Involuntary Nucleus: Uni Rhythmic: Either due to Blood Vessels (related to heart) Intercalated Discs: No Speed of Contraction: Slower
3
Q
Why do muscles have the ability to move?
A
- Contraction
- Irritability
- Extensibility
- Elasticity
4
Q
Connective Tissue Wrappings
A
- Cells are surrounded and bundled by connective tissue
- Endomysium: Enclosing a single muscle fiber
- Perimysium: Wraps around a fascicle (bundle) of muscle fibers
- Epimysium: Covers the entire skeletal muscle
- Fascia: On the outside of the epimysium
5
Q
Sites of Muscle Attachment
A
- Bones
- Cartilages
- Connective Tissue Coverings
6
Q
Skeletal Muscle Functions
A
- Movement
- Posture (Jelly Donut)
- Heat
- Stabilize Joints
7
Q
Sacrolemma
A
-Specialized plasma membrane
8
Q
Myosin Filaments
A
- Thick filaments
- Composed of the protein myosin
- Has ATPase enzymes
- have heads (extensions, or cross bridges)
- Myosin and actin overlap somewhat
9
Q
Actin Filaments
A
- Thin filaments
- Composed of a protein actin
- Anchored to the Z disc
10
Q
Sarcoplasmic Reticulum
A
- Specialized smooth endoplasmic reticulum
- Stores and releases calcium (calcium is important for energy production)
- Surrounds the myofibril
11
Q
Myofibrils
A
- aligned to give distinct bands
- I Band= Light band
- Contains only thin filaments (actin)
- A Band= Dark band
- Contains the entire length of the thick filaments (myosin)
- I Band= Light band
12
Q
Sacromere
A
- Contractile unit of a muscle fiber (z line to z line)
- Organization of the sacromere
- Myofilaments
- Thick filaments= myosin filaments
- Thin filaments= actin filaments
- Myofilaments
13
Q
What Skeletal Muscles need to Contract
A
- Strength of stimuli
- Ca+
- Na+
- Blood flow
- Glucose
- Red Blood Cells
- Oxygen (breaks down sugar)
- Iron (attracts oxygens)
- Phosphate bonds Cp+ ATP
- Number of mitochondria
- K+
14
Q
Graded Responses
A
-different degrees of skeletal muscle shortening
15
Q
How graded responses can be changed
A
- The frequency of muscle stimulation
- The number of muscle cells being stimulated at one time
16
Q
Twitch (Graded Response)
A
- Single, brief contraction
- Not a normal muscle function
17
Q
Tetanus (Type of Graded Response)
A
- Summing of contractions
- One contraction is immediately followed by another
- The muscle does not completely return to a resting state
- The effects are added
18
Q
Unfused Incomplete Tetanus (Graded Response)
A
- Some relaxation occurs between contractions
- The results are summed
19
Q
Fused Complete Tetanus (Graded Response)
A
- No evidence of relaxation before the following contractions
- The result is a sustained muscle contraction
20
Q
Flexion
A
- Ordinary Body Movement
- Decreases the angle of the joint
- Brings two bones closer together
- Typical of hinge joints like knee and elbow
21
Q
Extension
A
- Ordinary Body Movement
- Opposite of flexion
- Increases angle between two bones
22
Q
Rotation
A
- Type of Ordinary Body Movement
- Movement of a bone around its longitudinal axis
- Common in ball and socket joint
- Example is when you move atlas around the dens of axis (shake your head “no”)
23
Q
Abduction
A
- Ordinary body movement
- Movement of a limb away from the middle
24
Q
Adduction
A
- Ordinary body movement
- Opposite of Abduction
- Movement of a limb toward the midline
25
Circumduction
- Type of ordinary movement
- Combination of flexion, extension, abduction, and adduction
- Common in ball-and-socket joints
26
Dorsiflexion
- Ordinary movement
| - Lifting the foot so that the superior surface approaches the shin
27
Plantar Flexion
- Ordinary movement
| - Depressing the foot (pointing the toes)
28
Inversion
- Special Movement
| - Turn sole of foot medially
29
Eversion
- Special movement
| - Turn sole of foot laterally
30
Supination
- Forearm rotates laterally so palm faces anteriorly
- "Raise the roof"
- Special movement
31
Pronation
- Forearm rotates medially so palm faces posteriorly
| - Special movement
32
Opposition
- Move thumb to touch the tips of other fingers on the same hand
- Special movement
33
Types of Muscles
- Prime mover-- muscle with the major responsibility for a certain movement
- Antagonist: Muscle that opposes or reverses a prime mover
- Synergist: Muscle that aids a prime mover in a movement and helps prevent rotation
- Fixator-- Stabilizes the origin of a prime mover
34
Ways to Name Muscles
- By direction of muscle fibers (Ex: Rectus Abdominus
- By relative size of the muscle (Ex: Gluteus Maximus
- By location of the muscle (Ex: Temporalis)
- By the number of origins (Ex: Triceps= three heads)
- By location of the muscles origin and insertion (Sternocleidomastoid)
- By shape of the msucle (Ex: Deltoid)
- By action of the muscle ( Flexor &extensor)
35
Origin Vs. Insertion
- Origin= closer to the midline
| - Insertion= farthest from the midline
36
Anaerobic
- Starts w/ enzymes
- Glycolysis (splitting of glucose) C6H12O6--> c3h6o3 (pyruvic acid) and 2 ATP
- if oxygen does not get to it, it keeps breaking down to create lactic acid
- Produces:
- 2 ATP
- Lactic Acid
37
Aerobic Respiration
- Glucose --> pyruvic acid ---> Mitochondria uses Amino and fatty acids
- Produces:
- CO2
- h2o (water)
- 32 ATP (per glucose)
38
How much ATP is produced by each respiration cycle?
```
Krebs cycle= 2 ATP
Anaerobic = 2 ATP
Aerobic= 32 ATP
------------
36 ATP
```
39
Synaptic Cleft
- Gap between nerve and muscle
- Nerve and muscle do not make contact
- Area between nerve and muscle is filled with interstitial fluid
40
Neuromuscular Junction
-Association site of axon terminal of the motor neuron and muscle
41
Neurotransmitter
- chemical released by nerve upon arrival of nerve impulse
- The neurotransmitter for skeletal muscle is acetylcholine(ACh)
- Acetylcholine attaches to receptors on the sarcolemma
- Sarcolemma becomes permeable to sodium (Na+)
42
Tendons
- Cord-like structures
- Mostly collagen fibers
- Often cross a joint due to toughness and small size
43
Aponeurosis
- Sheet-like structures
| - Attach muscles indirectly to bones cartilages, or connective tissue coverings
44
Skeletal Muscle Characteristics
```
Where: Attached to bones
Appearance: Striated
Shape: Long Columnar
Action: Voluntary
Nucleus: Multi-nucleated
Rhythmic: Non-rhythmic
Intercalated Discs: No
Speed of Contraction: Slow to Fast
```
45
Steps to Muscle Contraction
1. An action potential in a motor neuron cause acetylcholine to release in the synaptic cleft
2. Acetylcholine binds with receptors on the cell membrane on the muscle fiber, opening Ca+ (Calcium) channels
3. Calcium is released from the terminal cisternae into the muscle fiber
4. Calcium binds to troponin
5. Troponin shifts tropomyosin, which was blocking the active site on the actin
6. Myosin heads attach to actin by breaking down ATP to ADP and a phosphate via Myosin-ATPase
7. The Myosin head forms a "cross bridge" on the active site of the actin filament
8. The cross bridge pulls actin, which slides over the myosin--- known as the Power Stroke
9. The release of ADP completes the cross-bridge movement and ATP attaches to myosin, breaking the actin-myosin cross-bridge
10. Every time ATP is split into ADP + P, the myosin head cocks into place to form another cross bridge with actin
-Entire process shortens the sarcomere, which is functional unit of a muscle cell
