Basic Tissues - Lecture 4 Flashcards
What are the four basic tissue types?
○ Epithelia
○ Connective Tissue
○ Muscle Tissue
○ Nervous Tissue
Main functions of the epithelial tissue?
○ Covers surfaces
○ Lines cavities and tubes
○ Forms glands
Characteristics of epithelial tissue
○ Attached to a basement membrane
○ Avascular (no blood vessels)
○ Capable of regeneration
○ Has polarity (apical and basal sides)
Describe simple squamous epithelium; include its function and location
○ Description: Flat cells, one layer
○ Function: Exchange of nutrients and gases
○ Location: Blood vessels, alveoli
Describe keratinised stratified squamous epithelium; include its function and location
○ Description: Flat surface cells, many layers, contains keratin
○ Function: Protection, waterproof barrier
○ Location: Skin
Describe non-keratinised stratified squamous epithelium; include its function and location
○ Description: Flat surface cells, many layers, no keratin
○ Function: Protection, barrier
○ Location: Oral cavity, oesophagus
Describe simple cuboidal epithelium; include its function and location
○ Description: Square cells, one layer
○ Function: Secretion and Absorption
○ Location: Glands, kidney tubles
Describe simple columnar epithelium; include its function and location
○ Description: Tall cells, one layer
○ Function: Absorption and secretion
○ Location: Gastrointestinal tract
Describe pseudostratified columnar epithelium with goblet cells; include its function and location
○ Description: Appears layered, but all cells touch basement membrane, contains cilia and goblet cells
○ Function: Mucociliary escalator
○ Location: Trachea and large respiratory airways
What are desmosomes?
○ Very strong connections between adjacent cells
○ Resist stretching and twisting
What are tight junctions?
○ Interlocking proteins tightly bind cells together near the apical edge
○ Prevent the passage of water and solutes between cells (e.g., in the digestive tract)
What are gap junctions?
○ Cells are held together by interlocking membrane proteins containing a central pore
○ Allow the movement of small molecules and ions between cells
What are hemidesmosomes?
○ Attach cells to the basement membrane
○ Stabilise the position and anchor cells
Functions of connective tissue
○ Forms a structural framework
○ Supports, surrounds, and interconnects other tissues
○ Protects delicate organs
○ Transports fluids and materials
○ Stores energy
○ Defends against microorganisms
Main components of connective tissue
○ Cells (fibroblasts, adipocytes, macrophages, mast cells)
○ Extracellular matrix (ground substance, tissue fluid, fibres)
What are the two main classifications of connective tissue?
○ Specialised (blood, bone, cartilage)
○ Connective tissue proper (loose or dense)
Describe loose (areolar) connective tissue; include its components and location
○ Description: Lots of ground substance, few fibres, variety of cells
○ Location: Under the epithelium
Describe dense irregular connective tissue; include its components and location
○ Description: Little ground substance, many haphazard collagen fibres, few cells
○ Location: Dermis
Describe dense regular connective tissue; include its components and location
○ Description: Little ground substance, many parallel collagen fibres, few cells
○ Location: Tendons and ligaments
Describe skeletal muscle; include its function and innervation
○ Description: Long, cylindrical, striated, multinucleated
○ Function: Moves and stabilises the skeleton, forms sphincters, respiration
○ Innervation: Somatic nervous system
Describe smooth muscle; include its function and innervation
○ Description: Short, fusiform, non-striated, single nucleus
○ Function: Gastrointestinal movement, alters diameter of airways and blood vessels
○ Innervation: Autonomic nervous system
Describe cardiac muscle; include its function and innervation
○ Description: Branched, striated, 1-2 central nuclei, intercalated discs
○ Function: Circulates blood, maintains blood pressure
○ Innervation: Autonomic nervous system
