Structural Organisation in Animals

Comprehensive vocabulary flashcards covering animal tissue types, structural components, and cockroach morphology based on the provided lecture transcript.

Tissue

A group of similar cells alongwith intercellular substances that perform a specific function.

Epithelium (Epithelial Tissue)

A tissue with a free surface facing either a body fluid or the outside environment, providing a covering or lining for parts of the body.

Simple Epithelium

A type of epithelium composed of a single layer of cells that functions as a lining for body cavities, ducts, and tubes.

Compound Epithelium

A type of epithelium consisting of two or more cell layers with a main function of providing protection against chemical and mechanical stresses.

Squamous Epithelium

Made of a single thin layer of flattened cells with irregular boundaries, found in the walls of blood vessels and air sacs of lungs.

Cuboidal Epithelium

Composed of a single layer of cube-like cells commonly found in ducts of glands and tubular parts of nephrons.

Columnar Epithelium

Composed of a single layer of tall and slender cells with nuclei located at the base, found in the lining of stomach and intestine.

Ciliated Epithelium

Columnar or cuboidal cells bearing cilia on their free surface used to move particles or mucus in a specific direction.

Glandular Epithelium

Specialised columnar or cuboidal cells for secretion, which can be unicellular (goblet cells) or multicellular (salivary gland).

Exocrine Glands

Glands that release products like mucus, saliva, and digestive enzymes through ducts or tubes.

Endocrine Glands

Ductless glands whose products, called hormones, are secreted directly into the fluid bathing the gland.

Tight Junctions

Specialised junctions that help to stop substances from leaking across a tissue.

Adhering Junctions

Junctions that perform cementing to keep neighbouring cells together.

Gap Junctions

Junctions that facilitate cell communication by connecting the cytoplasm of adjoining cells for rapid transfer of ions and small molecules.

Connective Tissue

The most abundant tissue in complex animals, named for its function of linking and supporting other tissues and organs.

Areolar Tissue

A type of loose connective tissue present beneath the skin that serves as a support framework for epithelium.

Adipose Tissue

A loose connective tissue located beneath the skin specialised to store fats from excess nutrients.

Tendons

Dense regular connective tissues that attach skeletal muscles to bones.

Ligaments

Dense regular connective tissues that attach one bone to another.

Chondrocytes

Cells of cartilage enclosed in small cavities within the matrix they secrete.

Osteocytes

Bone cells present in spaces called lacunae.

Blood

A fluid connective tissue containing plasma, red blood cells ($RBC$), white blood cells ($WBC$), and platelets.

Myofibrils

Numerous fine fibrils that compose long, cylindrical muscle fibres.

Smooth Muscle

Involuntary, non-striated muscle fibres that are fusiform (taper at both ends) and found in internal organ walls.

Intercalated Discs

Communication junctions in cardiac muscle that allow cells to contract as a unit by stimulating neighbours.

Neurons

Excitable cells that serve as the unit of the neural system.

Neuroglia

Cells that protect and support neurons, making up more than one-half the volume of neural tissue.

Periplaneta americana

The common species of adult cockroach, approximately $34-53\,mm$ long with wings extending beyond the abdomen in males.

Sclerites

Hardened plates of the cockroach exoskeleton, termed tergites dorsally and sternites ventrally.

Arthrodial Membrane

A thin and flexible articular membrane that joins the sclerites of a cockroach.

Hypopharynx

A median flexible lobe acting as a tongue within the mouthparts of a cockroach.

Tegmina

Opaque, dark, and leathery mesothoracic forewings of a cockroach that cover the hind wings at rest.

Anal Styles

Short, thread-like structures present in male cockroaches but absent in females.

Anal Cerci

A pair of jointed filamentous structures found on the $10^{th}$ segment in both male and female cockroaches.