Structural Organisation in Animals - Histology Lecture Notes

A collection of vocabulary flashcards covering the structural organization of animal tissues, including epithelial, connective, muscular, and neural systems, based on histology lecture notes.

Histology

The study of tissues.

BICHAT

Recognized as the Father of Histology.

Epithelial Tissue

A tissue that evolved first and forms first, characterized as being avascular and forming continuous layers on the outer or inner surfaces of body parts.

Basement Membrane

An acellular layer, also known as basal lamina, composed of glycoproteins and mucosaccharides that supports epithelial cells and facilitates chemical exchange between them and blood vessels.

Squamous Epithelium

A single layer of flattened polygonal cells with irregular boundaries; also known as Tessellated or Pavement epithelium.

Cuboidal Epithelium

A single layer of cube-like cells found in the ducts of glands, tubular structures, and the lining of the thyroid follicle and ovary.

Columnar Epithelium

A single layer of tall, slender cells with nuclei located at their base; they function in secretion and absorption.

Pseudostratified Epithelium

A single layer of cells that appears multilayered due to different cell sizes and nuclear positions, typically found in the trachea.

Exocrine Glands

Glands that pour their secretions through ducts, such as those for saliva, tears, oil, milk, sweat, and digestive enzymes.

Endocrine Glands

Ductless glands that pour hormones directly into the blood.

Compound Epithelium

A multilayered tissue that provides protection against chemical and mechanical stress, covering surfaces like the skin or the buccal cavity.

Transitional Epithelium

A type of stratified epithelium containing $4-6$ layers of cells.

Tight Junction

A leakproof cell junction that does not allow the movement of molecules and ions between cells, found in areas like the stomach and blood-brain barrier.

Adhering Junction

A junction that cements neighboring cells together; examples include hemidesmosomes.

Gap Junction

A cytoplasmic connection between cells that allows for the rapid chemical exchange of molecules and ions.

Mast Cells

Connective tissue cells that secrete histamine (a vasodilator), serotonin (a vasoconstrictor), and heparin (an anticoagulant).

Adipose Tissue

A type of loose connective tissue specialized to store fat, primarily found beneath the skin, around the heart, and in kidneys.

Signet Ring Cell

A cell found in adipose tissue where fat storage has pushed the nucleus and cytoplasm towards the periphery.

Tendon

A dense regular connective tissue that joins muscle to bone.

Ligament

A dense regular connective tissue that joins bone to bone.

Chondrocytes

Mature cartilage cells located in fluid-filled spaces called lacunae.

Haematopoiesis

The process of producing all types of blood cells, which occurs in the red bone marrow.

Osteocytes

Mature bone cells embedded in a hard, non-pliable matrix rich in calcium salts and collagen fibres.

Diapedesis

The process by which white blood cells (WBCs) move through the walls of blood vessels.

Skeletal Muscle

Striated, voluntary muscle tissue bundled together in a parallel manner and attached to bones.

Intercalated Disc

Communication junctions present in cardiac muscle that allow cells to contact and contract as a single unit.

Neuroglia

Non-excitable cells of the neural tissue that support, protect, and nourish neurons, constituting more than half the volume of nervous tissue.