Histology Flashcards

Endomysium (C)

Smooth muscle

Perimysium (b)

Striated squeletal muscle

Z line (C) or I band (B)

Intercalated disk (D)

Capillary (C)

Endothelial cell (B)

M line aka Morales line chica (A)

Intercalated disk (D)

Perineurium (C)

Intima (A)

Adventica (C)

Venule (C)

Muscular artery (A)

Elastic lamina (C)

Lumen of a large vein (C)

Arteriole (D)

Intima (D)

Media (B)

Media (B)

Elastic artery (D)

Arteriole and venule (D)

Media (B)

B
What is the smallest repetitive subunit of the contractile apparatus?
Sarcomere from Z line to Z line (2-3mm)
What are the types of bands/lines that change form during muscle contraction?
Pseudo H and I band change (smaller when contracting) but NOT A and M bands
By what are composed the A and I bands?
- A bands are composed of myosin (thick filaments)
- I bands are composed actin filaments where the contraction occurs
What ion is essential to muscle contraction?
CALCIUM (Ca2+)
Mechanism: Myofibrils are surrounded by sacroplasmic reticulum which secretes the Ca2+ that leads to the contraction. TnI inhibit the actin myosin interaction, TnC binds Ca2+ and TnT anchors to Tropomyosin that contracts the cells. Then the calcium comes back into the sacroplasmic reticulum. Contraction in striated muscle fibbers is quick, forceful and usually under voluntary control.
True or false: hyperplasia is normal in cardiac muscle cells
TRUE
Hyperplasia is normal, but NOT hypertrophy (hypertrophy is normal in squeletal muscles)
Which type of muscle does not have sacroplasmic reticulum surrounding microfibrils?
Smooth muscle cells. Note that they still need calcium to contract.
What differentiates
- Elastic artery
- Muscular artery
- Arteriole
- Large vein
- Middle size vein
- Venules
- Elastic artery: smooth muscle and elastic membrane
- Muscular artery: 4 or more concentric layer of smooth muscle
- Arteriole: 1-2 layers of smooth muscle cells
- Large vein: muscular separated by CT
- Middle size vein: fewer muscular cells
- Venules: no smooth muscle