Lab Exercise # 5

1. Lab Exercise # 5 Zoo- 145 HISTOLOGY Study of histological structure of different organs

2. Lab Exercise # 5 Zoo- 145 HISTOLOGY is the branch of Biology that studies the microscopic structure of the tissues, organs and systems under the microscope Type of Tissues Epithelial Tissue Muscular Tissue Connective tissue Nervous Tissue Spinal Cord Neuron Skeletal Muscle Cardiac Muscle Hyaline Cartilage *Blood Vessels: Arteries and Veins

3. Lab Exercise # 5 Zoo- 145 The Muscular Tissue Striated Muscle Skeletal muscle • Skeletal muscle is made up of individual components known as muscle fibers. • Each muscle fiber is formed of still finer fibers, myofibrils. • The identifying features of these muscles are haphazardغير منظم distribution of nuclei among the muscle fibers. • The fibers are also transversely marked with lines or striations, dark and light bands. • Each muscle fiber is encased in a membrane, myolemma.

4. Lab Exercise # 5 Zoo- 145 Nucleus Intercalated Disc Cardiac muscle • Muscle fibers form the unit of cardiac muscle like striated muscle. • Cardiac Muscle have all structures like that of striated muscles except the nucleus are very well arranged and equally distributed one in each muscle fiber. • Cardiac muscle fiber is jointed متصلةand each joint form a deep impression which is generally called Intercalated Disc.

5. Lab Exercise # 5 Zoo- 145

6. Lab Exercise # 5 Zoo- 145 The Connective Tissue Hyaline Cartilage • Hyaline cartilage is covered externally by a fibrous membrane, called theperichondrium. • The chondrocytes cells are round or oval in shape and are located in group of two or four in each cavity, Lacunae. • It contains lots of empty spaces in between the cells. The matter that support the cells and cavities is thick and is called the matrix.

7. Lab Exercise # 5 Zoo- 145 The Nervous Tissue Neurons Nucleus Dendrites • These are unit of Nervous Tissue and are specialized in function and shape. • The neurons or the nerve cells are star shaped bodies with few microns in diameter. • The sharp protrusions of these cells are named as dendrites and the number of such spine like extensions varies from 5 to 7. • Centrally, the star shaped mass is loaded with a small nucleus and cytoplasm around the nucleus

8. Lab Exercise # 5 Zoo- 145 The Nervous Tissue Spinal Cord • The Spinal cord is cylindrical structure present inside the vertebral column. • It is a bilobed tube and its dividing line toward dorsal side is called the dorsal fissure and the invaginating line toward ventral plane is called ventral fissure. • The depressed area on both planes is called the dorsal commissure toward dorsal side and ventral commissiure toward ventral side. • The central area is full of nerve cells and is named as grey matter which is perforated with a hole, central canal. • The area surrounding grey matter is called duramatter and the outer most covering of the spinal cord is termed as piamatter.

9. Lab Exercise # 5 Zoo- 145 The Nervous Tissue Spinal Cord

10. Lab Exercise # 5 Zoo- 145 Arteries and Veins Artery Vein • The basic structure of the artery is composed of three layers of different kinds of tissues: • outer most layer is composed of connective tissue and is called tunica adventitia. • the median layer is formed of unstriated muscles and is termed tunica media. • the inner most layer is formed of epithelial tissue and is termed as tunica intima. • The veins also contain three different layers of different tissue like arteries viz, Tunica Adventitia, Tunica Media and Tunica Intima. • The difference lies only in the thickness of these three layers. As a fact, the veins are thin walled vessels comparatively due to the thin muscular layer

11. Lab Exercise # 5 Zoo- 145 Thank you