Programme of next practicals April 17 th Revision

Programme of next practicals • April 17 th Revision practical + Microscopic structure of the heart and blood vessels. • April 24 th Blood cells: Cytology of formed elements of blood. Hematopoiesis – demonstration of developmental stages. Repetition test II (Epithelial tissue, muscle tissue and nervous tissue. ) • May 1 st, May 8 th - Holiday

General histology: Repetition Tissue types • • Connective and supporting (+blood) Epithelial Muscular Nervous

Connective tissue developed from mesenchyme consists of: • cells • intercellular matrix: a) amorphous ground substance b) fibers

Classification • connective tissue proper • specialized connective (supporting) tissue: cartilage ne bo Functions • mechanical (cartilage, bone) • nutritional (intercellular substance) • defensive (cells: histiocytes, plasma cells, leukocytes – immunocompetence, production of antibodies)

Connective tissue proper • • • mucous (jelly-like) loose collagenous (areolar) dense collagenous (regular, irregular) reticular elastic adipose tissue (white, brown)

Connective tissue proper Mucous (jelly-like) connective tissue

Loose (areolar) connective tissue

Dense connective tissue (regular, irregular)

Elastic tissue

Reticular tissue

Adipose tissue (white)

Cartilage composed of cells (chondrocytes) and intercellular matrix: fibers and amorphous substance (chondrocytes present in lacunae within the matrix) fibers: a) collagenous only b) combination of collagenous and elastic cartilage is nonvascular, without nerves perichondrium – dense irregular connective tissue on the surface: important for growth and nutrition of cartilage Classification according to the kind amount of fibers: – hyaline cartilage – elastic cartilage – fibrocartilage

Cartilage (hyaline)

Cartilage (elastic)

Fibrocartilage

Bone • Cells: osteocytes, osteoblasts, osteoclasts, osteoprogenitor cells • Intercellular matrix: collagenous fibers (type I), amorphous substance, inorganic salts • Macroscopically - 2 types: compact (dense) and spongy (cancelous) • Microscopically – 2 types according to the organisation of intercellular substance: woven (nonlamellar) and Haversian (lamellar)

Woven bone

Lamellar (Haversian) bone

Epithelial tissue Classification on the structural basis (arrangement of cells): • membranes – cells form sheets – the most common type, including most exocrine glands • trabecular – cells are arranged into anastomosing trabeculae – liver, endocrine glands • reticular – stellate cells form a network – thymus Classification on the basis of function : • Covering (lining) epithelia – epithelial membranes • Glandular epithelium • Absorptive epithelium – enterocytes (intestine) • Respiratory epithelium – pneumocytes (lung) • Sensory epithelium – olfactory ep. , taste buds • Myoepithelial cells (exocrine glands, m. dilatator pupillae)

Covering epithelia (epithelial membranes) • Simple squamous

Covering epithelia (epithelial membranes) • Simple cuboidal

Covering epithelia (epithelial membranes) • Simple columnar

Covering epithelia (epithelial membranes) • pseudostratified

Covering epithelia (epithelial membranes) • Stratified squamous nonkeratinized

Covering epithelia (epithelial membranes) • Stratified squamous keratinized

Covering epithelia (epithelial membranes) • Stratified columnar

Covering epithelia (epithelial membranes) • transitional

Glandular epithelium Unicellular glands Goblet cells Paneth cells

Glandular epithelium multicellular glands – ducts and secretory portions (acini, tubules)

Glandular epithelium • Multicellular glands – serous acini and mucous tubules

Muscle tissue Morphological unit of: • Skeletal muscle cell is called muscle fiber – rhabdomyocyte (multinucleated, nuclei at periphery) myofibrils are structures inside the cell, consist of myofilaments (actin, myosin) • Cardiac muscle cell – cardiomyocyte (uninucleated, nucleus centrally) myofibrils, intercallated discs • Smooth muscle cell – leiomyocyte (uninucleated, nucleus centrally) no myofibrils, only myofilaments

Skeletal muscle

Cardiac muscle

Smooth muscle

Nervous tissue Anatomically: • CNS (central nervous system): brain, spinal cord • PNS (peripheral nervous system): nerves, ganglia Histologically it consists of 2 principal cell types: • nerve cells (neurons) – excitability (irritability) and conductivity • supporting cells (neuroglia)

Types of neurons: pyramidal cells

Types of neurons: Purkinje cell

Types of neurons: motor neurons of spinal cord

Types of neurons: pseudounipolar neurons

Peripheral nerve

Peripheral nerve