Chapter 04 | Tissues

Epithelial Tissue

Epithelial Tissue

Forms protective coverings for all body surfaces, lines hollow organs, body cavities, and ducts.

Connective Tissue

Provides support and structure; the most abundant tissue type, connecting different tissues and storing energy.

Muscle Tissue

Enables movement by contracting in response to stimulation, essential for bodily functions.

Nervous Tissue

Facilitates communication between different body parts through nerve impulses.

Avascular but Innervated

Describes epithelial tissues that do not have blood vessels but receive nutrients through diffusion.

Polarity in Epithelial Tissue

Epithelial cells have an apical surface (exposed) and a basal surface (attached to connective tissue).

Simple Epithelium

A single layer of cells typically found where absorption, secretion, and filtration occur.

Stratified Epithelium

Multiple layers of cells that offer protection against abrasion and are found in high-wear areas.

Squamous Cells

Thin, flat epithelial cells that facilitate efficient gas exchange and filtration.

Cuboidal Cells

Cube-shaped epithelial cells involved in secretion and absorption.

Columnar Cells

Tall, column-shaped epithelial cells specialized for absorption and secretion.

Transitional Epithelium

Epithelial tissue that changes shape depending on stretching, found in the bladder.

Simple Squamous Epithelium

Single layer of flat cells facilitating diffusion and filtration.

Stratified Squamous Epithelium

Multiple layers of flat cells providing protection against mechanical stress.

Keratinized Epithelium

Type of stratified squamous epithelium that provides a waterproof barrier.

Non-Keratinized Epithelium

Type of stratified squamous epithelium that lines moist body openings.

Simple Cuboidal Epithelium

Cube-shaped cells arranged in a single layer, involved in secretion and absorption.

Glandular Epithelium

Epithelial tissue that forms glands and secretes substances like hormones.

Simple Columnar Epithelium

Column-like cells specializing in absorption and secretion; may contain goblet cells.

Goblet Cells

Specialized cells in columnar epithelium that produce mucus.

Pseudostratified Epithelium

Appears layered but is actually a single layer with nuclei at different levels.

Cilia

Hair-like structures that help move substances across the epithelial surface.

Areolar Tissue

Loose connective tissue that holds organs together and provides a reservoir of water and salts.

Adipose Tissue

Connective tissue that stores energy, insulates, and cushions organs.

Fibrous Tissue

Dense connective tissue with collagen fibers providing strength and support.

Bone Tissue

Supportive connective tissue with a calcified matrix, aiding movement and protecting organs.

Cartilage

Flexible connective tissue that provides support and flexibility in areas like joints.

Hyaline Cartilage

Type of cartilage found in joints, providing smooth surfaces for movement.

Elastic Cartilage

Type of cartilage that maintains shape and flexibility, found in the ear.

Fibrocartilage

Type of cartilage that provides strength and absorbs shock, found in intervertebral discs.

Blood

A fluid connective tissue that transports gases, nutrients, and immune cells.

Skeletal Muscle Tissue

Muscle tissue responsible for voluntary movements, striated and multinucleated.

Cardiac Muscle Tissue

Involuntary muscle tissue found only in the heart, striated and branched.

Smooth Muscle Tissue

Involuntary muscle tissue found in the walls of hollow organs, non-striated and spindle-shaped.

Neurons

Specialized cells that transmit electrical impulses in the nervous system.

Neuroglia (Glial Cells)

Supportive cells that aid neurons in the nervous system.

Axon

Long projection of a neuron that carries impulses away from the cell body.

Dendrites

Branch-like structures on a neuron that receive signals from other cells.

Myelin Sheath

Insulating layer surrounding the axon of a neuron, increasing signal transmission speed.

Astrocytes

Glial cells that support neurons and form the blood-brain barrier.

Fibrosis

The process in which fibrous connective tissue replaces original tissue, leading to scarring.

Keloid Formation

Overgrowth of collagen resulting in raised, thickened scars.

Regeneration

The process of repair and replacement of tissue, particularly evident in epithelial and connective tissues.

Tissue Repair

The mechanism by which the body restores tissue after injury, often involving regeneration.

Hematoma

A localized collection of blood outside of blood vessels, often forming after an injury.

Fibrocartilaginous Callus

A temporary tissue that forms during the healing of a bone fracture.

Osteoblasts

Bone-forming cells responsible for synthesizing new bone matrix.

Collagen Fibers

Strong protein fibers found in connective tissues that provide strength and support.

Collagen

The most abundant protein in the body, forming the primary structural component of connective tissue.

Myelination

The process of forming a myelin sheath around a neuron, which increases the speed of electrical impulses.

Electrical Impulses

Signals transmitted along neurons, enabling communication within the nervous system.

Extracellular Matrix

A complex network of proteins and carbohydrates outside of cells that provide structural and biochemical support.

Pseudostratified Ciliated Columnar Epithelium

Type of epithelium that appears stratified but is a single layer, containing cilia and goblet cells.

Fluid Matrix

A type of matrix in connective tissue, characterized by a liquid consistency, like blood plasma.

Striated Muscle Cells

Muscle cells with a banded appearance, as seen in skeletal and cardiac muscle.

Intercalated Discs

Specialized connections between cardiac muscle cells that allow synchronized contractions.

Goblet Cell Function

To produce mucus, providing lubrication and protection to epithelial surfaces.

Osteocytes

Mature bone cells that maintain the bone matrix.

Lacunae

Small cavities in cartilage and bone where chondrocytes or osteocytes reside.

Neurotransmitters

Chemicals released by neurons to transmit signals to other neurons or muscles.

Peristalsis

The involuntary contraction and relaxation of smooth muscle to move food through the digestive tract.

Regeneration in Connective Tissue

The process by which connective tissues repair themselves after injury.

Blood Clotting

The process of coagulation that prevents excessive bleeding and initiates healing.

Blood-Brain Barrier

A selective barrier that protects the brain from potentially harmful substances in the bloodstream.

Fibroblasts

Cells in connective tissue that produce collagen and other fibers.

Neuroglial Support

The variety of functions that glial cells perform to support and protect neurons.

Chondrocytes

Cells found in cartilage that maintain cartilage structure and function.

Apical Surface

The surface of epithelial cells that faces the body exterior or the lumen of an organ.

Basal Surface

The surface of epithelial cells that is attached to the underlying connective tissue.

Ground Substance

The non-cellular material that fills the space between cells in connective tissues.

Simple Columnar with Microvilli

Specialized simple columnar cells that have microvilli to increase surface area for absorption.

Inflammation

The body's response to injury or infection, often part of the healing process.

Scarring

The result of fibrosis where fibrous tissue replaces normal tissue, often affecting functionality.

Epithelial Cell Regeneration

The rapid division and movement of epithelial cells to heal and restore tissue integrity.

Connective Tissue Types

Includes areolar, adipose, fibrous, bone, cartilage, and blood.

Matrix Composition

Describes the variety of substances (fibers and ground substance) that make up the connective tissue matrix.

Voluntary Muscle Control

Control of muscle that requires conscious thought, typical in skeletal muscle.

Involuntary Muscle Control

Muscle movement that occurs without conscious control, as seen in cardiac and smooth muscle.

Cell Body (Neuron)

The part of a neuron that contains the nucleus and organelles.

Neural Communication

The process by which neurons transmit signals to each other or to muscles.

Tissue Types with High Regeneration

Epithelial and connective tissues, which typically regenerate effectively after injury.

Hematopoiesis

The process of blood cell formation occurring in the bone marrow.

Adipose Tissue Locations

Found under the skin, around internal organs, and in bone marrow.

Multinucleated Cells

Cells that contain more than one nucleus, characteristic of skeletal muscle fibers.