Mar 12 Muscle Physiology 1 Flashcards
3 Types of Muscles in The Human Body
Type
Strait or smooth
Voluntary or involuntary
Where?
3 Types of Muscles in The Human Body
Skeletal
- straited tubular
- Voluntary control
- Used in Movement
Cardiac
- straited branched
- involuntary control
- Only in the heart
Smooth
- Smooth spindled
- involuntary control
- Internal organs
Types of contractions (6)
Types of contractions
Circular
Convergent
Multipennate
Paraellel
Unipennate
Bipennate
Types of muscle contractions
Name 3
Types of muscle contractions
Isometric - no movement
Eccentric - Bicep uncurl
Concentric - Bicep curl
Skeletal Muscles HEALTH?
Skeletal muscle also helps?
Skeletal Muscles HEALTH?
Skeletal muscle also helps regulate body temperature, and it can secrete over 600 different proteins or products that impact your overall health and function!
Exercise Myokines
*Myokines are?
Exercise Myokines
*Myokines are proteins (or other secretory products) released from skeletal muscle that have mostly beneficial effects on various tissues (sometimes called exerkines)
Skeletal Muscle Structure
(5 things)
Skeletal Muscle Structure
Each muscle fiber is a single cylindrical muscle cell that contains multiple myofibrils.
Muscle fibers (cells) are bundled together to form fascicles.
An individual skeletal muscle may be made up of hundreds or thousands of muscle fibers bundled together and wrapped in a connective tissue covering.
Each muscle is surrounded by a connective tissue sheath called the epimysium.
Fascia, connective tissue outside the epimysium, surrounds and separates the muscles.
Components of Muscles
(Name 5 and what they do)
Components of Muscles
Nucleus
- Governs cell behaviours
- Controls DNA
Sarcolemma
- Muscle cell membrane
Sarcoplasm
- Muscle cytoplasm
- Fluids that hold organelles
Sarcoplasmic Reticulum
- Key calcium storage and release
- Calcium is needed for muscle contractions
Myofibrils
- Contains filament where muscle contraction takes place
- Overlap to form sacromeres
A sarcomere is defined as?
The striated appearance of skeletal muscle fibers is due to?
A sarcomere is defined as the region of a myofibril contained between two cytoskeletal structures called Z-discs (also called Z-lines or Z-bands).
The striated appearance of skeletal muscle fibers is due to the arrangement of the thick (myosin) and thin (actin) myofilaments within each sarcomere.
The dark striated A band is composed of?
The thick filaments are anchored at?
The dark striated A band is composed of the thick filaments of myosin, which span the center of the sarcomere extending toward the Z-dics.
The thick filaments are anchored at the middle of the sarcomere (the M-line) by a protein called myomesin. The lighter I band regions contain the thin actin filaments anchored at the Z-discs by a protein called
α actinin.
A sarcomere is defined as?
However?
This is called the?
A sarcomere is defined as the distance between two consecutive Z discs or Z lines; when a muscle contracts, the distance between the Z discs is reduced. So….for a muscle cell to contract, the sarcomere must shorten.
However, thick and thin filaments, the components of sarcomeres, do not appear to shorten with contraction…. Instead, they “slide” by one another, causing the sarcomere to shorten while the filaments remain the same length. When a sarcomere shortens, some regions shorten, whereas others stay the same length!
This is called the sliding filament theory of muscle contraction, which was developed to fit the differences observed in the named bands on the sarcomere at different degrees of muscle contraction and relaxation.
During contraction, the:
The length of the:
During contraction, the myofilaments themselves do not change length but slide across each other, so the distance between the Z-discs shortens, resulting in the shortening of the sarcomere.
The length of the A band does not change (the thick myosin filament remains a constant length), but the H zone and I band regions shrink.
