Animal Tissues - Vocabulary Flashcards

Flashcards of key vocabulary from the animal structural organisation lecture notes.

Tissue

A group of similar cells along with intercellular substances performing a specific function in multicellular animals.

Organ System

Two or more organs performing a common function by physical and/or chemical interaction.

Epithelial Tissue

Tissue with a free surface facing a body fluid or the outside environment, providing covering or lining for a body part; cells are compactly packed.

Simple Epithelium

Composed of a single layer of cells; functions as a lining for body cavities, ducts, and tubes.

Compound Epithelium

Consists of two or more cell layers; has a protective function (e.g., skin).

Squamous Epithelium

Single thin layer of flattened cells with irregular boundaries; found in walls of blood vessels and air sacs of lungs; involved in diffusion.

Cuboidal Epithelium

Single layer of cube-like cells; found in ducts of glands and tubular parts of nephrons in kidneys; functions in secretion and absorption.

Columnar Epithelium

Single layer of tall and slender cells; nuclei located at the base; found in the lining of stomach and intestine; helps in secretion and absorption.

Ciliated Epithelium

Columnar or cuboidal cells bearing cilia on their free surface; moves particles or mucus in a specific direction; found in bronchioles and fallopian tubes.

Glandular Epithelium

Columnar or cuboidal cells specialized for secretion; can be unicellular (goblet cells) or multicellular (salivary gland).

Exocrine Glands

Secrete mucus, saliva, earwax, oil, milk, digestive enzymes, etc., through ducts or tubes.

Endocrine Glands

Do not have ducts; secrete hormones directly into the fluid bathing the gland.

Tight Junctions

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

Adhering Junctions

Cell junctions that perform cementing to keep neighboring cells together.

Gap Junctions

Cell junctions that facilitate cell communication by connecting the cytoplasm of adjoining cells for rapid transfer of ions, small molecules, etc.

Connective Tissue

Tissues that link and support other tissues/organs of the body; range from soft connective tissues to specialized types like cartilage, bone, adipose, and blood.

Collagen/Elastin

Structural proteins secreted by connective tissue cells, providing strength, elasticity, and flexibility to the tissue.

Matrix

Modified polysaccharides secreted by connective tissue cells that accumulate between cells and fibers (ground substance).

Loose Connective Tissue

Cells and fibers loosely arranged in a semi-fluid ground substance (e.g., areolar tissue); serves as support framework for epithelium.

Fibroblasts

Cells in loose connective tissue that produce and secrete fibers.

Adipose Tissue

Type of loose connective tissue specialized to store fats; located mainly beneath the skin.

Dense Connective Tissue

Fibers and fibroblasts compactly packed; can be dense regular (collagen fibers in rows between parallel bundles) or dense irregular (fibers oriented differently).

Tendons

Dense regular connective tissues that attach skeletal muscles to bones.

Ligaments

Dense regular connective tissues that attach one bone to another.

Cartilage

Specialized connective tissue with solid and pliable intercellular material; resists compression; chondrocytes enclosed in cavities within the matrix.

Bones

Specialized connective tissue with hard and non-pliable ground substance rich in calcium salts and collagen fibers; provides structural frame to the body.

Blood

Fluid connective tissue containing plasma, red blood cells (RBC), white blood cells (WBC), and platelets; helps in the transport of various substances.

Muscle Tissue

Composed of long, cylindrical fibers (myofibrils); contracts in response to stimulation, then relaxes; plays an active role in body movements.

Skeletal Muscle

Muscle tissue closely attached to skeletal bones; striated muscle fibers bundled together in a parallel fashion.

Smooth Muscle

Muscle fibers that taper at both ends (fusiform) and do not show striations; found in the wall of internal organs; involuntary.

Cardiac Muscle

Contractile muscle tissue present only in the heart; cell junctions fuse plasma membranes, allowing cells to contract as a unit; communication junctions (intercalated discs).

Neural Tissue

Exerts the greatest control over the body’s responsiveness to changing conditions; neurons (excitable cells) and neuroglial cells (protect and support neurons).

Neurons

The functional unit of the neural system; excitable cells that generate and transmit electrical disturbances.

Neuroglia

Cells that protect and support neurons in the neural system.

Morphology

Study of form or externally visible features of organisms.

Anatomy

Study of the morphology of internal organs in animals.

Metameres

The similar short segments which the earthworm body is divided into (about 100-120 in number).

Prostomium

A lobe which serves as a covering for the mouth and as a wedge to force open cracks in the soil into which the earthworm may crawl. The prostomium is sensory in function.

Peristomium

The first body segment also known as buccal segment which contains the mouth.

Clitellum

A prominent dark band of glandular tissue covering segments 14-16 in a mature earthworm.

Nephridiopores

Numerous minute pores that open on the surface of the earthworm body.

Setae

S-shaped structures extended or retracted, embedded in the epidermal pits in the middle of each earthworm segment. Their principal role is in locomotion.

Calciferous glands

Present in the stomach of the earthworm. They neutralize the humic acid present in humus.

Typhlosole

The characteristic feature of the intestine between 26-35 segments of the earthworm which increases the effective area of absorption in the intestine.

Nephridia

Segmentally arranged coiled tubules in earthworms that regulate the volume and composition of the body fluids.

Cerebral ganglia

Integrate sensory input as well as command muscular responses of the earthworm body.

Spermathecae

Located in 6th-9th segments of the earthworm. They receive and store spermatozoa during copulation.

Spermatophores

Packets of sperms which are mutually exchanged between two worms during mating.

Oothecae

Capsules containing fertilized eggs which are encased in capsules in cockroaches.

Vermicomposting

The process of increasing fertility of soil by the earthworms.

Sclerites

Hardened plates of the exoskeleton in each cockroach segment (tergites dorsally and sternites ventrally).

Arthrodial membrane

A thin and flexible articular membrane by which sclerites are joined to each other.

Hypopharynx

A median flexible lobe, acting as tongue, that lies within the cavity enclosed by the cockroach mouthparts.

Tegmina

Forewings (mesothoracic) of the cockroach which are opaque dark and leathery and cover the hind wings when at rest.

Anal cerci

A pair of jointed filamentous structures borne on the 10th segment in both sexes of the cockroach.

Mosaic vision

Vision with more sensitivity but less resolution, being common during night which cockroach possess.

Urecose glands

The structure that also help in excretion in addition to the Malpighian tubules, fat body, nephrocytes.

Gonapophysis

External genitalia represented by male gonapophysis or phallomere (chitinous asymmetrical structures, surrounding the male gonopore).

Paurometabolous

Development meaning there is development through nymphal stage of P. americana.

Poikilotherms

Animals which do not have constant body temperature i.e., their body temperature varies with the temperature of the environment.

Mimicry

The protective coloration is called mimicry.

Aestivation

Summer sleep.

Hibernation

Winter sleep.

Nictitating membrane

A membrane that protects bulged eyes of frog when in water.