Muscle Anatomy Flashcards
What is the characteristic of skeletal muscles?
- Fibres are large and striate
- Multinucleated
What is the characteristic of cardiac muscle?
- Fibres striated but smaller than skeletal muscle
- Uninucleated
- Joined by intercalated disks
What is the characteristic of smooth muscle?
- Fibres are small
- Lask striation
What are tendons compromised of?
- Type I and III collagen
- Elastin
- Proteogylcans
- Tendon fibroblasts
What do tendons do?
Attach muscle to bone
What do ligaments do?
Attach bone to bone
What is the purpose of the T tubule?
Facilitate the rapid and synchronised transmission of electrical signals from the cell surface to the sarcoplasmic reticulum
What region is the sarcomere?
The region between two Z-lines
What are I bands?
Thin filaments not on thick filaments
What are A bands?
The entire length of a single thick filament
What are H zones?
Area of thick filament without any thin filament
What is the M line?
Is in the middle of the sarcomere and contains cross connecting elements of the cytoskeleton
What happens to the I band when contraction occurs?
It becomes smaller
What happens to the H zone when contraction occurs?
It become smaller
What is titin?
Filament which anchors the thick filament to the Z disc
What is the sarcoplasmic reticulum?
Specialised form of the endoplasmic reticulum found in muscle cells, crucial for calcium ion storage, release, and re-uptake
What are pacemaker cells?
Specialised heart cells that spontaneously initiate electrical impulses triggering each heartbeat and controlling heart rate
What is the purpose of gap junctions in intercalated disks?
Allow the electrical waves of depolarisation to travel from cell to cell allowing for almost simultaneous contraction of entire myocardium
What can smooth muscles be triggered by?
- Signal ligand
- Autorhythmic
- Stretch
What is single unit smooth muscle?
Smooth muscle that has cells connected by electrical transmitting gap junction
What is multi unit smooth muscle?
Smooth muscle that has cells that function independently of each other
