Week 4 Histopathology (Muscle)

Question 1

Indicate whether these muscle types are striated or non-striated. Skeletal: Smooth: Cardiac:

Answer 1

Skeletal: striated Smooth: non-striated Cardiac: striated

Question 2

Where is the nucleus found in the three types of the muscles? # of nuclei? cytoplasm:nuclei ratio?

Answer 2

Skeletal: periphery, multiple nuclei, large Smooth: centrally located, 1 nucleus, low c:n ratio Cardiac: centrally located, 1 nucleus, high c:n ratio

Question 3

What is this an image of?

Answer 3

Skeletal muscle (note: multiple nuclei on periphery)

Question 4

What is this an image of?

Answer 4

Skeletal muscle, longitudinal section

Question 5

What is circled in blue and green? Where is this image from?

Answer 5

This image is from the middle esophagus

Blue: Smooth musclue

Green: Skeletal muscle

Question 6

What is this an image of?

Answer 6

Smooth muscle, longitudinal (note: the elongated nucleus, centrally located, lack of striations)

Question 7

What is this an image of? Also, what is marked by the green arrow?

Answer 7

Cardiac muscle, longitudinal

Green arrows: intercalated disks

Question 8

Describe the difference b/t epimysium, perimysium, and endomysium.

Answer 8

Epimysium: heavy layer of connective tissue surrounding the entire muscle

Perimysium: Connective tissue surround each fasicle (group of skeletal muscle cells)

Endomysium: The ring around the ECM