Types of Muscle Tissues

Characteristics of ALL Muscle Cells Changes-- _________________________ Respond to stimuli with electrical changes_________________ 2 Purposes– more than a local electrical change; leading to muscle contraction Consequences– of muscles ____________ –shortens when stimulated; pull on bones and other tissues ____________ -- capable of being stretched; in other cells— ____________-- returns to its original resting length after being stretched

There are 3 types of muscle tissue:  _________

Classification of Muscle Cells ______________________ striated have a banded appearance (stripes) _______________or multinucleated cells voluntarily (consciously) or involuntarily (automatically)

Skeletal Muscle Tissue

Cardiac Muscle Tissue

Smooth Muscle Tissue

Review What You’ve Learned… Muscle Type Striated? # of nuclei Voluntary or Involuntary

Muscle Fiber Anatomy

Skeletal Muscles- Organs of skeletal muscle tissue - ___________________________________________ Muscular System- Includes only skeletal muscles Skeletal Muscle Structures Muscle tissue (muscle cells or fibers) Connective tissues Nerves Blood vessels

6 Functions of Skeletal Muscles ___________________ Maintain body position and posture _______________________ Guard body openings (entrance/exit) ______________________ Store Nutrient reserves

How is muscle tissue organized at the tissue level How is muscle tissue organized at the tissue level? Organization of Connective Tissues Figure 10–1

Organization of Connective Tissues Muscles have 3 layers of connective tissues: 1. Epimysium-______________________ Connected to deep fascia Separates muscle from surrounding tissue 2. perimysium- _______________________-(fascicles) Contains blood vessel and nerve supply to fascicles 3. ___________

3. Endomysium Surrounds individual muscle cells (muscle fibers) __________________________________________________ Contains satellite cells (stem cells) that repair damage

Muscle Attachments Endomysium, perimysium, and epimysium come together: _________________ __________________________________________________________ i.e., tendon (bundle) or aponeurosis (sheet)

Nerves Skeletal muscles are voluntary muscles, controlled by nerves of the central nervous system Blood Vessels Muscles have extensive vascular systems that: ____________________ _____________________ carry away wastes

What are the characteristics of skeletal muscle fibers? _______________________________ Figure 10–2

Skeletal Muscle Fibers Are very long Develop through fusion of mesodermal cells (myoblasts- embryonic cells)) _____________________ Contain hundreds of nuclei –_______________ Unfused cells are satellite cells- assist in repair after injury

Organization of Skeletal Muscle Fibers Figure 10–3

The Sarcolemma The cell membrane of a muscle cell Surrounds the sarcoplasm (cytoplasm of muscle fiber) _____________________________________________________________ All regions of the cell must contract simultaneously

Transverse Tubules (T tubules) _______________________________________________________________ Allow entire muscle fiber to contract simultaneously Have same properties as sarcolemma Filled with extracellular fluid

Myofibrils- 1-2um in diameter Lengthwise subdivisions within muscle fiber Made up of bundles of protein filaments (myofilaments) Myofilaments - are responsible for muscle contraction 2 Types of Myofilaments Thin filaments: _____________________ Thick filaments: ____________________

Sarcoplasmic Reticulum (SR) A membranous structure surrounding each myofibril __________________________________ Similar in structure to smooth endoplasmic reticulum Forms chambers (terminal cisternae) attached to T tubules

A Triad _______________________________________________________________ Cisternae Concentrate Ca2+ (via ion pumps) Release Ca2+ into sarcomeres to begin muscle contraction

Structural components of the Sarcomeres -The contractile units of muscle -Structural units of ____________ -Form visible patterns within myofibrils Figure 10–4

Muscle Striations A striped or striated pattern within myofibrils: alternating dark, thick filaments ________and light, thin filaments _________

M Lines and Z Lines M line: Z lines: Zone of Overlap ____________________ at midline of sarcomere Z lines: the centers of the I bands _________________ Zone of Overlap The densest, darkest area on a light micrograph __________________

The H Zone The area around the M line _______________________________

Sarcomere Structure Figure 10–5

Sarcomere Function Transverse tubules encircle the sarcomere near zones of overlap Ca2+ released by SR causes thin and thick filaments to interact

Level 1: ____________ Level 2: __________________ Figure 10–6 (1 of 5)

Level 4: _____________l Figure 10–6 (3 of 5)

Level 5: ___________ Figure 10–6 (5 of 5)