Lab 06 & 07 - Part I: Connective Tissue & Musculoskeletal System

Connective Tissue

Connective Tissue Proper

• Classification:
  • Made up of loose and densely packed elastic fibers, fibroblasts, and collagen fibers

Loose Connective Tissue

• Functions: Hold organs and other tissues in place by providing a flexible network of fibers embedded in a gel-like ground substance

1. Areolar Tissue:

   • Located in the papillary layer of the dermis
   • Contains loosely arranged collagen and elastic fibers with scattered fibroblasts

2. Reticular Tissue:

   • Located in the liver, spleen, bone marrow, lymph nodes, etc.
   • Composed of loosely arranged reticular fibers

3. Adipose Tissue:

   • Found under the skin, around organs, and in bone marrow
   • Stores excess calories as fat, containing adipocytes.

Dense Connective Tissue

• Structure: Primarily composed of tightly packed collagen fibers and fibroblasts, making it flexible and resistant to tension

1. Dense Regular Tissue:

   • Located in tendons and ligaments
   • Densely arranged with a collagen fiber matrix and a few cells (fibroblasts); fibers are parallelly arranged

2. Dense Irregular Tissue:

   • Located in the deep dermis
   • Composed of a dense matrix of collagen fibers with randomly oriented fibers

Special Connective Tissue: Bone & Cartilage

Cartilage

• Composed of a rigid matrix formed by chondroblasts, chondrocytes, collagen fibers, and elastic fibers.
• Types of Cartilage:

1. Hyaline Cartilage:

   • Amorphous and rigid matrix
   • Location: Articular cartilage in long bones, costal cartilage (ribs to sternum), embryonic skeleton

2. Elastic Cartilage:

   • Similar to hyaline but has more elastic fibers
   • Location: Ear, epiglottis

3. Fibrocartilage:

   • Contains thick collagen in the matrix, less firm than hyaline cartilage; absorbs shock
   • Location: Intervertebral discs, knee joints

Bone

• Has a rigid matrix formed of collagen fibers, osteoblasts, and calcium salts
• Osteocytes: Mature bone cells
• Functions of Bone:
  • Protection, Support, Movement, Mineral storage.

Musculoskeletal System

• Composed of bones, muscles, joints, tendons, ligaments, cartilage, and connective tissue

Upper Body Anatomy

• Skull Bones:

  • Occipital, Parietal, Temporal, Sphenoid, Mandible, Frontal, Lacrimal, Nasal, Ethmoid, Zygomatic, Maxilla

• Skull Sutures:

  • Sagittal suture, Coronal suture, Lambdoid suture, Squamous suture

• Vertebral Column:

  • Composed of 7 cervical, 12 thoracic, 5 lumbar vertebrae, sacrum & coccyx

• Muscles of the Thoracic Region:

  • Inspiration:
  • External intercostals (contracts to elevate ribs), diaphragm (expands thoracic cavity)
  • Expiration:
  • Internal intercostals (pulls ribs down), diaphragm (relaxes to reduce thoracic cavity)

• Muscles of the Back:

• Latissimus Dorsi: Side bending, rotation of head, elevating and depressing shoulders

• Trapezius: Medial rotation, adduction, and extension of humerus, respiration

• Muscles of the Abdominal Region:

  • Rectus Abdominis: Flexes vertebral column, tenses abdominal wall
  • Internal Oblique: Compresses abdominal viscera, flexes spine, laterally flexes trunk
  • External Oblique: Compresses abdomen, flexes spine, rotates trunk to opposite side