Tissues Flashcards
What are the four types of tissue?
- Epithelial
- Connective
- Muscle
- Nervous
Where is epithelial tissue located?
- Exterior surfaces of body
- Lining of internal cavities and passageways
- Forms certain glands
Where is connective tissue usually found?
- Binds cells and organs together
- Protects and supports all parts of body
What are the three types of muscle tissue?
- Skeletal muscle
- Smooth muscle
- Cardiac muscle
Function of nervous tissue?
- Allows propagation of nerve impulses for communication in body
What are the three major cell lineages established within the embryo?
- Ectoderm
- Mesoderm
- Endoderm
In which layer does epithelial tissue originate in?
All three layers (ectoderm, mesoderm, endoderm)
In which layer does nervous tissue primarily originate from?
Ectoderm
In which layer does muscle tissue primarily originate from?
Mesoderm
What are the two types of tissue membranes?
- Connective
- Epithelial
Function of connective tissue?
Support and protect tissues and organs
What are the categories of connective tissue?
- Loose and dense
- Supportive
- Fluid
Where are connective membranes generally found in the body?
In the lining of movable joints and around organs
Where are epithelial membranes generally found in the body?
In the lining of body cavities and hollow passageways that open to external environment
Function of epithelial tissue?
- Protects internal environment
- Controls material exchange between internal and external environment
Which tissue type is most prone to genetic mutations and cancer?
Epithelial
This is due to epithelial tissue regularly dividing and reproducing throughout their lifespan due to wear and tear.
What are the five functional types of epithelia?
- Exchange
- Transporting
- Ciliated
- Protective
- Secretory
What is the function of tight junctions?
- Separates cells into apical and basal compartments
- Creates blood-brain barrier
What is the function of anchoring/adhesive junctions?
Stabilizes epithelial cells
Common on lateral and basal cell surfaces
What are the three types of anchoring/adhesive junctions?
- Desmosomes
- Hemidesmosomes
- Adherens
What is the function of gap junctions?
Form intercellular passageways between adjacent cell membranes to allow ion/molecule movement
Define:
Cadherins
Adhesion molecules embedded in patches, important for holding cells together
Define:
Integrins
Adhesion proteins
Define:
Squamous cell shape
Flat, thin
Define:
Cuboidal cell shape
Boxy
Define:
Columnar cell shape
Rectangular, taller
Define:
Simple cell layer
- One cell layer
- Basal lamina (thin layer of extracellular matrix between cells)
Define:
Stratified cell layer
Multiple cell layers
Define:
Transitional stratified cell layer
Specialized stratified epithelium in which cell shape varies
Define:
Pseudostratified cell layer
Single layer of irregularly shaped cells that look like multiple layers
Define:
Gland
Structure made up of one or more cells modified to synthesize and secrete chemical substances
What are the two types of glands?
- Exocrine
- Endocrine
Define:
Endocrine gland
- Ductless, release secretions directly into surrounding tissues and fluids
What is the function of endocrine glands?
- Secrete hormones into interstitial fluid
- Coordinate regulation and integration of body responses
Define:
Exocrine glands
Release contents via duct to epithelial surface
What are the two types of exocrine glands?
- Goblet cells (unicellular)
- Serous glands (multicellular)
Exocrine glands can be classified by:
- Mode of secretion
- Nature of substances released
- Structure of glands/duct shape
What is the most common type of exocrine secretion?
Merocrine secretion
What are the types of glandular secretion?
- Merocrine secretion
- Apocrine secretion
- Holocrine secretion
Define:
Merocrine secretion
Cell remains intact
Define:
Apocrine secretion
Accumulates near apical portion of cell and portion is pinched off and released
Define:
Holocrine secretion
Involves rupture and destruction of entire gland cell
What is the function of fixed cells?
- Local maintenance
- Tissue repair
- Energy storage
What are the type of fixed cells?
- Fibrocytes
- Adipocytes
- Mesenchymal cells
What is the function of mobile cells?
Defense
What are the three main types of connective tissue fibers?
- Collagen fibers
- Elastic fibers
- Reticular fibers
What is the function of collagen fibers?
- Resist stretching
- Hold connective tissues together during movement
What are the properties of elastic fibers?
Returns to original shape after being stretched/compressed
Where are reticular fibers mostly found?
In soft organs such as liver/spleen
What is the function of loose connective tissue?
Allows water, salts, and nutrients to diffuse through adjacent/embedded cells/tissues
Adipose tissue consists mostly of:
Fat storage cells with little extracellular matrix
What are the two types of dense connective tissues?
- Regular dense
- Irregular dense
How are collagen fibers arranged in regular dense connective tissue?
Parallel to one another
How are collagen fibers arranged in irregular dense connective tissue?
In mesh-like network
What are the three types of supportive connective tissues?
- Hyaline cartilage
- Fibrocartilage
- Elastic cartilage
Define:
Hyaline cartilage
- Most common
- Smooth surface
- Short and dispersed
- Found in rib cage, nose
Define:
Fibrocartilage
- Tough, thick collagen fibers dispersed throughout matrix
Define:
Elastic cartilage
- Contains elastic fibers, collagen, and proteoglycans
- Gives support and elasticity
What is the function of bone tissue?
Protects internal organs and supports body
What feature of bone tissue allows for quick recovery from injuries?
High vascularization
What type of connective tissue would bone tissue be classified as?
Supportive connective tissue
What type of connective tissue is blood classified as?
Fluid connective tissue
What are the two types of cells found in blood?
- Erythrocytes (red blood cells)
- Leukocytes (white blood cells)
What is the function of red blood cells?
Transports oxygen and carbon dioxide
What is the function of white blood cells?
Defends against harmful microorganisms or molecules
