Muscle And Peripheral Neural Tissue (Foundations Exam 1)

Front 1

Smooth muscle features and locations

Back 1

- relatively weak, slow contractions, involuntary control
- contains few blood vessels, bordered by CT
- found in the walls of hollow organs -- gastrointestinal tract, portions of the reproductive and urinary tracts, walls of blood vessels, respiratory passages
- can regulate peristalsis in gut, blood pressure and air flow in blood vessels and bronchi

Front 2

Smooth muscle fibers

Back 2

- elongated cells,spindle-shaped
- single nucleus, located near center of cell
- profiles vary in diameter
- "cork screw" nuclei
- no special cells with stem-like properties
- "dense bodies" where actin filaments in smc's attach to each other and to plasma membrane

Front 3

skeletal muscle features

Back 3

- rapid, powerful contractions under voluntary control
- dense, collagenous sheath of CT
- blood vessels and nerves run in CT, penetrate outer sheath

Front 4

skeletal muscle fibers

Back 4

- size: large, ~uniform <10x RBC
- staining: eosinophilic
- Nuclei: multiple, peripheral
- long, straight, unbranched, striated
- form muscle fascicles
- satellite cells have stem-cell properties

Front 5

cardiac muscle features

Back 5

- regular, powerful contractions, not under voluntary control
- found only in the heart and the portion of the pulmonary veins where they join the heart
- lots of blood vessels and CT
- very few satellite cells or stem cells -->does not regenerate to any significant extent

Front 6

Cardiac muscle fibers

Back 6

- long, organized into fascicles, striated and contain sarcomeres
- stain eosinophilic
- branched
- 1 or 2 nuclei near center of cell
- intercalated discs

Front 7

Function of intercalated discs

Back 7

1. anchor sarcomeres
2. intercellular adhesion
3. allow rapid communication of electrical and chemical signals between muscle fibers

Front 8

Structural components of intercalated discs

Back 8

1. fascia adherens - anchors sarcomeres and contributes to cell-cell adhesion
2. desmosomes - contribute to cell-cell adhesion
3. gap junctions - rapid communication between cells

Front 9

parasympathetic ganglia

Back 9

contents: neuron cell bodies, unmyelinated neuronal processes, and schwann cells
- branch into submucosal plexus
- large nuclei belong to neuron
- small nuclei belong to schwann cells

Front 10

peripheral nerves

Back 10

- contain myelinated axons, unmyelinated axons or mixture of two
- sympathetic nerves is ganglia
- parasympathetic nerves in hollow organs
- nuclei belong to schwann cells
- three layers: epineurium, perineum, endoneurium

Front 11

myelin

Back 11

- multiple layers of wrapping around axons
- schwann cell wraps around portion of axon
- multiple nuclei seen on histology
- nodes of ranvier are unique to neural tissue
- increases conduction velocity