Structures and Functions of Animal Cells – Lecture 2.2

Vocabulary flashcards covering key terms from the lecture on animal cell structure, tissue types, and levels of biological organization.

Chemical level

Atoms and biomolecules (carbohydrates, proteins, lipids, nucleic acids) that form the basis of life.

Organelle level

Membrane-bound subcellular structures, such as mitochondria and the nucleus, that perform specific cellular functions.

Cell level

The smallest, basic functional unit of life; examples include skin cells, blood cells, and neurons.

Tissue level

Groups of similar cells working together to perform a specialized function.

Organ level

Groups of tissues cooperating to carry out a particular function—for example, the heart or lungs.

Organ system level

Groups of organs that coordinate to perform a body process, such as the circulatory or respiratory system.

Organism level

An individual living entity composed of interacting organ systems.

Population level

Members of the same species living in a defined area.

Community level

Different populations inhabiting and interacting within the same area.

Ecosystem level

A community of organisms interacting with each other and with their physical environment.

Biosphere level

All of Earth’s ecosystems—the global zone where life exists.

Epithelial tissue

Tightly packed cells forming body coverings, linings, and glands; functions in protection, absorption, and secretion.

Simple squamous epithelium

Single layer of flat cells (e.g., alveoli, capillaries) specialized for diffusion and filtration.

Simple cuboidal epithelium

Single layer of cube-shaped cells (kidney tubules, gland ducts) involved in absorption and secretion.

Simple columnar epithelium

Single layer of tall cells (gastrointestinal tract) containing goblet cells; specialized for absorption and mucus secretion.

Pseudostratified columnar epithelium

Single layer of cells with varying heights, often ciliated (respiratory tract), for secretion and movement of mucus.

Stratified squamous epithelium

Multiple layers of flat cells (epidermis, mouth lining) providing protection against abrasion.

Stratified cuboidal epithelium

Two or more layers of cube-shaped cells (sweat and salivary glands) for protection and secretion.

Stratified columnar epithelium

Several layers with surface column-shaped cells (male urethra, some gland ducts) for protection and secretion.

Connective tissue

Cells embedded in an extracellular matrix of ground substance and fibers; supports, binds, and protects body parts.

Bone (osseous tissue)

Rigid connective tissue with calcified matrix and collagen fibers that supports and protects body structures.

Cartilage

Flexible connective tissue with chondrocytes in a firm matrix; provides support and cushioning (hyaline, fibro, elastic).

Dense connective tissue

Matrix rich in closely packed collagen fibers with few cells; forms tendons and ligaments for strong attachment.

Loose connective tissue

Softer matrix with more cells and fewer fibers; includes areolar, adipose, and reticular tissues for cushioning and support.

Areolar tissue

Loose connective tissue that cushions organs, holds tissue fluids, and provides a soft packaging around body structures.

Adipose tissue

Fat-storing loose connective tissue that insulates, stores energy, and cushions organs—critical for polar bear survival in winter.

Reticular connective tissue

Loose network of reticular fibers that forms an internal framework supporting lymphoid organs.

Blood

Fluid connective tissue with plasma and formed elements; transports substances, defends, and clots.

Muscular tissue

Specialized tissue whose cells contract to produce movement.

Skeletal muscle

Long, multinucleated, striated fibers attached to bones; responsible for voluntary body movements.

Smooth muscle

Spindle-shaped, non-striated cells in walls of hollow organs; involuntary control of visceral functions.

Cardiac muscle

Striated, branched cells with intercalated discs in the heart; involuntary pumping of blood.

Nervous tissue

Tissue composed of neurons and glial cells that receive, process, and transmit electrochemical impulses.

Neuron

Nerve cell capable of generating and conducting electrical signals throughout the body.

Astrocyte

Star-shaped CNS glial cell that supports neurons and regulates their chemical environment.

Microglial cell

Small CNS glial cell that becomes phagocytic to remove neuronal debris and pathogens.

Ependymal cell

Ciliated CNS glial cell lining brain ventricles and spinal canal; forms a barrier between cerebrospinal fluid and nervous tissue.

Oligodendrocyte

CNS glial cell that produces the myelin sheath around nerve fibers.

Satellite cell (glia)

PNS glial cell that surrounds neuron cell bodies, providing support and regulating their environment.

Schwann cell

PNS glial cell that wraps nerve fibers and forms the myelin sheath.