Download Muscle Development: Understanding Skeletal, Cardiac, and Smooth Muscle and more Summaries Animal Anatomy and Physiology in PDF only on Docsity!
Muscle Tissue
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary SEM of partly unraveled skeletal muscle cell exposing the densely packed myofibrils within.
Muscle Tissue
1. Muscle is a highly cellular and vascular tissue
specialized for contraction via the interaction of
myofilaments (between thin and thick filaments );
it is responsible for movement of the body and for
changes in the size and shape of internal organs.
2. There are three basic types of muscle tissue
( skeletal , smooth , and cardiac ) classified according
to appearance of their contractile cells and location.
3. Striated muscle is formed during development by the
fusion of small individual muscle cells called
myoblasts into larger, multinucleated myotubes.
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary
Keywords
A-band
Cardiac muscle
Endomysium
Epimysium
Fascicles
I-band
Intercalated disc
Muscle fiber
Myoblast
Myocardium
Myocytes
Myofibrils
Myotube
Perimysium
Sarcoplasmic reticulum
Satellite cell
Skeletal muscle
Smooth muscle
Striated muscle
Striations
T tubule
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary
Slide 7: Larynx, Trichrome
look here to see
skeletal muscle in
longitudinal-section
look here to see
skeletal muscle in
cross-section
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary
skeletal muscle
surface of tongue;
what specific type
of tissue is this?
Slide 70: Tongue, H&E
skeletal muscle (or visceral striated muscle, as seen in the tongue) is generally responsible for voluntary
movement within the body, mainly of the skeleton but also other structures such as the eyes and upper
esophagus for swallowing; it is composed of long multinucleated cells called muscle fibers which generally
extend the entire length of a muscle from tendon to tendon (up to 2ft long in the sartorius muscle in the thigh)
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 70: Tongue, H&E
skeletal muscle
in longitudinal-section
skeletal muscle
in cross-section
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 8: Tongue, Trichrome
skeletal muscle
in longitudinal-section
skeletal muscle
in longitudinal-section
skeletal muscle fiber
in cross-section
fibroblast of the
endomysium CT
nucleus of a muscle fiber
displaced to the periphery,
directly under the sarcolemma
numerous capillaries can be seen in the
endomysium between the muscle fibers
using the know size of an RBC, estimate
the diameter of an adjacent muscle fiber
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 17 (464): Skeletal Muscle, H&E
cross-striations (fine lines) are the alternating dark and light bands formed by the arrangement of the
myofilaments of the sarcomere (best seen in electron micrographs); the dark bands are the A-bands
(overlapping actin and myosin filaments) and the light bands are the I-bands (actin filaments); the visible
striations are the reason both skeletal and cardiac muscle are classified as striated muscle
nuclei of skeletal muscle
fibers are displaced to the
periphery of the cells directly
beneath the sarcolemma
a few nuclei of fibroblasts,
forming the endomysium
or perimysium, may be
seen but can be difficult to
identify; the nuclei of
endothelial cells of
capillaries can also be seen
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 139: Heart, H&E
intercalated discs are highly specialized cell-to-cell adhesion junctions found in cardiac muscle; they
physically bind cells together to create long muscle fibers, so the force of contraction is transmitted between
the cells; they also promote the spread of action potentials from cell to cell via gap junctions
intercalated disc
(thick, dark lines)
“branching” of fibers
is characteristic of
cardiac muscle
cross-striations
(thin, faint lines)
round, centralized
nucleus of cardiac
muscle is distinct from
the multinucleated
peripheral, elongated
what is this nuclei of skeletal muscle
“wear and tear”
pigment found
near the nuclei
in cardiac fibers?
myofibrils
(parallel to fiber direction)
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 66: Esophagus, H&E
look in the inner layer to
see smooth muscle in
longitudinal-section
lumen
look in the outer layer to
see smooth muscle in
cross-section
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 66: Esophagus, H&E
skeletal muscle
fiber
(cross-section)
smooth muscle
fiber
(cross-section)
the upper 1/3 of the esophagus is under voluntary control so has skeletal muscle ( voluntary muscle ); the
lower 2/3 is under involuntary control so has smooth muscle ( visceral muscle ); on this slide, from the
middle portion of the esophagus, the transition between the two muscle types can be seen
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 66: Esophagus, H&E
unlike skeletal muscle, smooth muscle makes its own surrounding CT, so fibroblasts are much more rare;
however, scattered throughout the tissue, the nuclei of endothelial cells (simple squamous epithelium)
may be seen lining capillaries
cross-section
longitudinal
capillary
capillary
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 159: Fetal Mouse Head
look in the oral cavity at the
tongue to see developing
skeletal muscle
vertebrae
endochondral
ossification
developing brain
cartilaginous
nasal septum
newly-forming woven
bone of the mandible
Slide Overview
IUSM – 2016
I. Introduction II. Learning Objectives III. Keywords IV. Slides A. Types of Muscle
- Striated a. Skeletal b. Cardiac
- Smooth B. Muscle Development (Skeletal) V. Summary Slide 159: Fetal Mouse Head
during embryonic development, mesenchymal myoblast cells fuse to form multinucleated myotubes ,
which will later further differentiate to form mature, striated skeletal muscle fibers
myotubes
myoblasts are the
skeletal muscle
precursor cells found
interspersed amongst
the myotubes
