Tissues - 4a Flashcards
What is a tissue?
A group of specialised cells and surrounding substances working together to perform a specific function.
What are the 4 basic tissue types?
Epithelial, connective, muscular, and nervous tissue.
Which tissue type covers surfaces and forms glands?
Epithelial tissue.
Which tissue type supports and protects the body and organs?
Connective tissue.
Which tissue type is specialised for contraction?
Muscular tissue.
Which tissue type detects and transmits nerve impulses?
Nervous tissue.
What is the function of tight junctions?
To form a fluid-tight seal between cells.
Where are tight junctions commonly found?
In the gastrointestinal tract and bladder.
What is the function of adherens junctions?
To help cells resist separation during contractile activity.
Where are desmosomes found and what is their role?
Found in skin and cardiac muscle; they provide strength and stability.
What do hemidesmosomes do?
Anchor epithelial cells to the basement membrane.
What is the function of gap junctions?
Allow communication between cells via connexins.
Is epithelial tissue vascular or avascular?
Avascular (no direct blood supply).
What are the three surfaces of epithelial cells?
Apical (top), lateral (sides), and basal (bottom).
What lies beneath the basal surface of epithelial tissue?
The basement membrane (made of basal lamina + reticular lamina).
What are the three arrangements of epithelial cells?
Simple, stratified, and pseudostratified.
What are the four epithelial cell shapes?
Squamous, cuboidal, columnar, and transitional.
Where is simple squamous epithelium found and what does it do?
In lungs, kidneys, and blood vessels; it aids diffusion and filtration.
Where is simple cuboidal epithelium found?
In kidney tubules, glands, and ovary surface.
What is the function of non-ciliated simple columnar epithelium?
Absorption and mucus secretion (often contains microvilli and goblet cells).
Where is ciliated simple columnar epithelium found?
In the respiratory tract and fallopian tubes.
What’s special about pseudostratified columnar epithelium?
Appears multilayered but all cells touch the basement membrane.
Where is stratified squamous epithelium found and what is its function?
Skin, mouth, vagina; provides protection.
What is transitional epithelium and where is it found?
A stretchy epithelium found in the bladder and ureters.
