Hist Lab 5 - Muscle

All three types of muscle (skeletal, cardiac, and smooth) are composed of cells (also
called fibers) specialized to shorten, or contract. All muscle fibers have an elongated
shape, oval euchromatic nuclei, and acidophilic cytoplasm filled with contractile
filaments (actin and myosin). Skeletal and cardiac muscle fibers have visible
cytoplasmic striations due to the complex arrangement of the actin and myosin
filaments into repeating units called sarcomeres and myofibrils.

Skeletal muscle (longitudinal section). You can see the cross striations consisting of dark and light lines (known as A and I bands).
*need to know longitudinal section vs. cross section (said in lecture).
-lots of nuclei

Smooth muscle (longitudinal section). The arrows are pointing to smooth muscle nuclei.

Cardiac muscle (longitudinal section). The arrows are pointing to intercalated discs. The branching cardiac muscle have striations but they are not visible in the slide.

Skeletal muscle (longitudinal)

spongy bone

Osteoblasts

Hyaline cartilage

Osteon (Haversian system) in compact bone

endosteum

dense regular connective tissue

chondrocyte

fibrocartilage

adipose tissue

Cardiac Muscle (longitudinal), has striations, and intercalated discs (red arrows). The branching nature of the fibers is evident

-know bands

loose connective tissue

simple squamous epithelium

Intercalated disc

A single Purkinje fiber

simple squamous endo of the endocardium of the heart

Purkinje fiber in endocardium

Purkinje fiber

smooth, pointing to cigar shaped nuclei,

smooth muscle running concentrically in the wall of a muscular artery

Transitional

Collagen (type I) fiber

nuclei of smooth muscle (green) vs fibroblast (yellow triangle)

– skeletal muscle (in cross section, x.s.)

hyaline cartilage (with lots of cells)

smooth longitudinal is L and cross is X

serous cell

Loose connective tissue with a lot of cells

smooth muscle

Mast cells

cardiac and cross

Intercalated discs

skeletal muscle

smooth muscle (around a vessel)

Hyaline cartilage

spongy

– smooth muscle (in a vessel)

smooth muscle

smooth muscle

transitional epithelium

dense irregular connective tissue