1. PowerPoint by John McGill Supplemental Notes by Beth Wyatt
Chapter 11 Supplement 2 Muscle Physiology CARDIAC AND SMOOTH MUSCLE TISSUE
PowerPoint by John McGill
Supplemental Notes by
Beth Wyatt

2. CARDIAC MUSCLE TISSUE LOCATION MAJOR FUNCTION TYPE OF CONTROL
Located in the Wall of the Heart
MAJOR FUNCTION
Pumps Blood (By Contraction)
TYPE OF CONTROL
Involuntary

3. Cardiac Muscle STRUCTURAL FEATURES
STRIATIONS
Present (Striated)
Means Sarcomeres Present
NUCLEUS
1/Cell

4. Cardiac Muscle STRUCTURAL FEATURES
T TUBULES
Present*
SARCOPLASMIC RETICULUM
* NOTE: Though Both Are Present, Their Arrangement Is Different Than in SMF’s (Less Extensive; Ca++ In From Outside the Cell)

5. Cardiac Muscle SPECIAL FEATURES
INTERCALATED DISCS
Junctions That Tightly Join Cardiac Muscle Fibers Lengthwise
BRANCHING
Transverse Connections Between Fibers

6. Cardiac Muscle METHOD OF CONTRACTION
SYNCYTIUM
Cardiac Muscle Tissue Contracts as a SYNCYTIUM (Unit of Combined Cells)
Due To Special Features (Intercalated Discs & Branching)(Creates a Continuous Sarcolemma)

7. Cardiac Muscle METHOD OF CONTRACTION
SELF‑EXCITING (myogenic)
Cardiac Muscle Tissue is Self‑Exciting
Doesn't Need Stimulation by Nerve Impulses
Stimulation Comes from Within the Tissue (Conduction System)

8. SMOOTH MUSCLE TISSUE LOCATION MAJOR FUNCTION TYPE OF CONTROL
Located in the Viscera
MAJOR FUNCTION
Movement of a Substance Through the Hollow Organ (By Contraction)
i.e., Food through Digestive System
TYPE OF CONTROL
Involuntary

9. SMOOTH MUSCLE TISSUE STRUCTURAL FEATURES
STRIATIONS
Absent (Nonstriated, Smooth)
Means Sarcomeres Absent
Thick and Thin Myofilaments Are Present
Not Arranged in Sarcomeres (Not as Extensive)
Arrangement of Thick and Thin Myofilaments Different
(Myofilaments Criss-cross and Attach to Sarcolemma)

10. SMOOTH MUSCLE TISSUE STRUCTURAL FEATURES
NUCLEUS
1/Cell
T TUBULES
Absent
SARCOPLASMIC RETICULUM
Present But Poorly Developed (Ca++ Comes In From Outside The Cell)

11. SMOOTH MUSCLE TISSUE METHOD OF CONTRACTION
Method of Contraction Depends upon Type of Smooth Muscle Tissue
VISCERAL (SINGLE UNIT): SYNCYTIUM/SELF‑EXCITING
Most Common Type of Smooth Muscle Tissue
Contracts Like Cardiac Muscle Tissue

12. SMOOTH MUSCLE TISSUE METHOD OF CONTRACTION
Method of Contraction Depends upon Type of Smooth Muscle Tissue
MULTI UNIT: INDIVIDUAL CONTRACTION/EXCITED BY NERVE IMPULSES
Contracts Like Skeletal Muscle Tissue (Motor Units Present)
Example: Arrector Pili Muscles