5-Muscle-Tissue.pdf, Schemes and Mind Maps of Histology

Download 5-Muscle-Tissue.pdf and more Schemes and Mind Maps Histology in PDF only on Docsity!

MUSCLE TISSUE

Larry Johnson Texas A&M University

Objectives

• Histologically identify and functionally characterize each

of the 3 types of muscle tissues.

• Describe the organization of the sarcomere as seen in

light and electron microscopy.

• Identify the endomysium, perimysium, and epimysium CT

sleeves in muscle.

• Relate the functional differences of the three muscle cell

types.

From: Douglas P. Dohrman and TAMHSC Faculty 2012 Structure and Function of Human Organ Systems, Histology Laboratory Manual

MUSCLE

• DISTRIBUTION:

SKELETAL – STRIATED MUSCLES

MOSTLY ASSOCIATED WITH THE

SKELETON

MUSCLE

• DISTRIBUTION:

SKELETAL – STRIATED MUSCLES

MOSTLY ASSOCIATED WITH THE

SKELETON

CARDIAC – STRIATED MUSCLES

ASSOCIATEWD WITH THE HEART

MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE – VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI

MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE – VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI CARDIAC MUSCLE – SHORT BRANCHING STRIATED MUSCLE CELLS WITH CENTRALLY LOCATED NUCLEI

MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE – VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI CARDIAC MUSCLE – SHORT BRANCHING STRIATED MUSCLE CELLS WITH CENTRALLY LOCATED NUCLEI SMOOTH MUSCLE – CLOSELY PACKED SPINDLE-SHAPED CELLS WITH A SINGLE CENTRALLY PLACED NUCLEUS AND CYTOPLASM THAT APPEARS HOMOGENEOUS BY LIGHT MICROSCOPY

Myoepithelial cells

Muscle Tissue Skeletal Muscle Smooth Muscle Cardiac Muscle Longitudinal sections

• Peripheral nuclei
• Striations
• No branching Longitudinal sections
  • Central nuclei (often fusiform)
  • Meshwork appearance of cells
  • No striations Longitudinal sections
    • Central nuclei (often elongated)
    • Striations
    • Branching cells
    • Intercalated discs Cross section
• Peripheral nuclei
• Massive cytoplasm Cross section
  • Central nuclei
  • Low cytoplasm to nucleus ratio Cross section - Central nuclei - High cytoplasm to nucleus ratio
• Muscle cells specialized for contraction with apparatus of actin

and myosin proteins.

• 3 types:

Slide 052: Skeletal muscle (longitudinal and cross sections) Cross striations (A and I bands) Muscle fibers with peripheral nuclei Capillary

Slide 052: Skeletal muscle (longitudinal and cross sections) Cross striations (A and I bands) Muscle fibers with peripheral nuclei Capillary The increase in muscle mass during exercise results from stimulating formation of new myofibrils and enlargement in the diameter of individual muscle fibers (hypertrophy = increase in size).

CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE

• EPIMYSIUM - COARSE CT
• PERIMYSIUM - LESS COARSE CT EPIMYSIUM PERIMYSIUM

CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE

• EPIMYSIUM - COARSE CT
• PERIMYSIUM - LESS COARSE CT
• ENDOMYSIUM - DELICATE CT EPIMYSIUM PERIMYSIUM ENDOMYSIUM

Slide 11: Skeletal muscle (longitudinal and cross sections) Epimysium Perimysium Endomysium

Slide 052 Skeletal muscle (longitudinal and cross sections) Perimysium Endomysium with its capillaries