Plant and Animal Tissues Flashcards

Vocabulary flashcards covering animal and plant tissue types, structures, and functions based on the lecture material.

Striated Muscles

Muscles made up of long, cylindrical, multinucleate cells with light and dark bands (striations) attached to the skeleton that are voluntary in action.

Unstriated Muscles

Involuntary muscles composed of spindle-shaped cells with a single central nucleus and no striations, located along the walls of internal organs like the digestive tract and urinary bladder.

Cardiac Muscles

Specialized, involuntary, branched muscle cells present only in the heart that contain striations, a single nucleus per cell, and perform rhythmic contraction and relaxation tirelessly throughout life.

Neuron

A highly specialized nerve cell that receives and transmits messages across the body in the form of electrical impulses.

Cyton

The cell body of a neuron consisting of a mass of cytoplasm enclosed by a plasma membrane with a central nucleus.

Dendrites

Root-like branching structures extending from the cyton that receive signals from the axon terminals of other nerve cells.

Axon

A thin, elongated structure extending away from the cyton that transmits electrical signals over short and long distances to the axon terminal.

Myelin Sheath

An insulating covering surrounding the axon that allows efficient transmission of electrical impulses.

Cartilage

A flexible supportive connective tissue without blood supply that contains chondrocytes embedded in a matrix of collagen, elastic fibres, and calcium salts.

Astrocytes

Bone cells situated inside lacunae arranged in concentric rings of matrix called lamellae.

Haversian Canal

A central canal in bone tissue surrounded by concentric lamellae that carries blood vessels to supply oxygen and nutrients to bone cells.

Plasma

The straw-coloured liquid matrix of blood consisting of approximately $90\%$ water.

Erythrocytes

Red blood cells containing haemoglobin that transport oxygen throughout the body, possessing a lifespan of about $120\,\text{days}$.

Leucocytes

White blood cells that protect the body against disease-causing microorganisms and defend against infections.

Thrombocytes

Platelets that initiate the blood clotting process to stop bleeding following an injury.

Lymph

A straw-coloured watery fluid derived from interstitial fluid that contains white blood cells, water, proteins, glucose, and salts to defend against infection.

Areolar Tissue

A loose connective tissue with scattered cells and collagen and elastic fibres in a semifluid matrix that binds the skin to muscles.

Adipose Tissue

A loose connective tissue containing fat-storing adipocytes that cushions internal organs and protects against extreme cold and mechanical trauma.

Tendons

Cord-like, inelastic dense connective tissues composed of white fibrous tissue and collagen that connect skeletal muscles to bones.

Ligaments

Flexible dense connective tissues formed from yellow fibrous tissue containing collagen and elastic fibres that connect bone to bone at joints.

Cuticle

A waxy layer secreted by the leaf epidermis that prevents plant parts from drying out.

Parenchyma

Simple permanent plant tissue composed of thin-walled, living spherical or oval cells with prominent nuclei and large vacuoles, responsible for synthesizing and storing food.

Chlorenchyma

Photosynthetic parenchymatous tissue containing chloroplasts found mainly in leaves.

Aerenchyma

Parenchymatous tissue with large intercellular air spaces found in aquatic plants that provides buoyancy for floating.

Collenchyma

Simple permanent plant tissue made of living elongated cells with pectin-thickened corners that provides mechanical support, elasticity, and flexibility.

Sclerenchyma

Simple permanent plant tissue composed of dead, thick-walled cells impregnated with lignin that provide structural rigidity and mechanical strength.

Fibres

Elongated sclerenchyma cells with tapering ends and simple pits present in stems, leaf midribs, xylem, and phloem.

Sclereids

Small, irregular or branched sclerenchyma cells with thick lignified walls that give texture to seed coats and fruit pulp.

Xylem

Complex permanent tissue made of dead, thick-walled cells such as tracheids and vessels that transports water and mineral salts upward from roots to leaves.

Phloem

Complex permanent tissue composed of living sieve tubes and companion cells that conducts prepared food bidirectionally throughout the plant.

Secondary Xylem

Wood tissue formed by secondary growth from cambium in woody trees, primarily composed of tracheids and vessels.

Annual Rings

Concentric light-coloured and dark-coloured rings formed annually in woody trunks that indicate yearly growth patterns.