Tissue Review: Connective Tissue and Tissue Types (Lecture Notes)

Vocabulary flashcards covering key connective tissue concepts, tissue types, cell types, and structures from the lecture notes.

Connective tissue (CT)

A primary tissue type with cells and an extracellular matrix; functions include support, protection, framework, transport, and defense; examples include fat, blood, bone, and cartilage.

Extracellular matrix (ECM)

Material outside cells in CT that contains ground substance and protein fibers; provides structure and influences cell behavior.

Ground substance

The noncellular component of ECM; can be liquid, gel-like, or solid; surrounds cells and fibers and facilitates water retention and exchange of signals.

Fibroblast

The most important permanent CT cell; synthesizes and secretes collagen, elastic, and reticular fibers and helps form the ground substance.

Adipocyte

Fat cell; stores triglycerides; forms adipose tissue; provides insulation, padding, and energy reserves; associated with yellow bone marrow.

Mast cell

CT immune cell located near blood vessels; releases histamine during inflammatory responses to dilate vessels.

Macrophage

Wandering phagocytic white blood cell; clears debris and pathogens, increases after tissue injury.

Mesenchymal cell

Multipotent stem cell in CT that can differentiate into various CT cell types.

Areolar connective tissue

Loose CT; light and airy packing material containing all three fiber types; found under epithelium and in the dermis; mobile and widely distributed.

Loose connective tissue

CT with loosely arranged fibers and more space between cells; includes areolar and adipose tissues.

Dense connective tissue

CT with densely packed fibers and fewer cells; provides strength; includes dense regular, dense irregular, and elastic CT.

Dense regular connective tissue

Collagen fibers arranged parallel; resists stress in one direction; forms tendons and ligaments; avascular.

Dense irregular connective tissue

Collagen fibers arranged irregularly; resists stress in multiple directions; found in dermis and organ capsules.

Elastic connective tissue

CT rich in elastic fibers (elastin); allows stretch and recoil; found in lungs and large arteries.

Blood (fluid connective tissue)

Fluid CT consisting of plasma with cells (RBCs, WBCs, platelets); carries gases, nutrients, and wastes.

Lymph

Fluid CT that circulates in lymphatic vessels; part of immune surveillance and transport of immune cells and waste.

Cartilage

Firm, flexible CT with chondrocytes in lacunae; avascular and aneural; provides support and cushioning.

Chondrocyte

Cartilage cell that resides in a lacuna and maintains the cartilage matrix.

Lacuna

Small cavity in bone or cartilage housing an osteocyte or chondrocyte.

Hyaline cartilage

Most common cartilage; glassy extracellular matrix; found at bone ends, fetal skeleton, and nasal/respiratory regions; supports with some flexibility.

Elastic cartilage

Cartilage with abundant elastic fibers; found in the ear and epiglottis; more cells in lacunae.

Fibrocartilage

Strongest cartilage type; dense collagen fibers; found in intervertebral discs and menisci; highly durable.

Osteocyte

Bone cell located in a lacuna; maintains bone matrix; derived from osteoblasts.

Lacuna (bone)

Cavity within bone matrix housing an osteocyte.

Canaliculi

Small channels connecting lacunae; enable nutrient and waste exchange between osteocytes.

Compact bone

Dense bone tissue organized into osteons; central canal with lamellae and lacunae housing osteocytes; provides strength.

Osteon

Structural unit of compact bone; concentric lamellae around a central (Haversian) canal.

Intercalated disc

Specialized junctions between cardiac muscle cells; allow rapid electrical conduction and synchronized contraction.

Striations

Striped appearance in skeletal and cardiac muscle due to organized sarcomeres; helps identify muscle types.

Skeletal muscle

Voluntary, striated muscle attached to bones; multinucleated with peripheral nuclei; used for movement and heat generation.

Cardiac muscle

Involuntary, striated muscle of the heart; branched cells with intercalated discs; single or double central nucleus; pumps blood.

Smooth muscle

Involuntary, nonstriated muscle; spindle-shaped cells with a single nucleus; lines hollow organs and vessels; moves substances.

Nervous tissue

Tissue containing neurons and neuroglia; neurons conduct electrical impulses; neuroglia support and nourish neurons.

Neuron

Nerve cell that conducts electrical impulses.

Neuroglia

Supportive cells of nervous tissue; do not conduct impulses but nourish, protect, and support neurons.

Basement membrane

Thin layer that anchors epithelium to underlying CT; separates epithelium from connective tissue.

Subcutaneous layer

Layer beneath the dermis consisting of fat (adipose tissue) and areolar CT; not a true skin layer.

Epithelial vs connective tissue space

Epithelial tissue is tightly packed with little intercellular space; connective tissue has abundant extracellular matrix and space between cells.

Vascularity of CT and cartilage

Most CT is vascular; cartilage is avascular and heals slowly due to lack of blood supply.