Chapter 3 - Tissue Types Flashcards
what are the two components of a tissue?
cells and matrix
what is epithelial tissue?
-sheets of cells that cover every exposed body surface and line internal cavities and passageways that are avascular, organized in sheets that are highly regenerative
what are the 4 functions of epithelial tissue?
1) protection - through regeneration
2) controls permeability
- blood vessel = single layer of epithelial tissue
3) sensation (neuroepithelial - cells responsible for special senses)
4) specialized secretions - glandular epithelium
what is the function of cilia?
-these are longer than microvilli and help move stuff
what is the function of microvilli?
-line passageways where we need more absorption (increase surface area)
which structures are affected in smokers lungs? Crohn’s disease?
smoker: cilia (hard to move stuff out of respiratory tract)
Crohn’s: microvilli (absorption)
how are epithelial tissues classified?
1) layering
- simple
- stratified
- pseudo-stratified
2) shape of cells
- squamous
- cuboidal
- columnar
squamous cell
- flat cell, usually thin (e.g. epithelial lining of skin; cross-section of blood vessel)
- lining of tongue; internal mouth
- peritoneum of heart
where is the nucleus of a columnar cell?
usually at basement membrane
how do we classify the type of epithelial cell?
by the top (superficial) layer
cuboidal cell
- cube-shaped
- found in different ducts
- nucleus in center of cell
- e.g. stratified: sweat and mammary gland ducts
- e.g. simple: glands, ducts, nephron tubules
columnar cell
-lines almost entire length of digestive tract (simple columnar) except for mouth and anus (stratified squamous)
give examples of simple columnar cell-type tissues
-stomach, intestinal tract, uterine tubes, excretory ducts
give examples of stratified columnar cell-type tissues
-pharynx, urethra, anus, excretory ducts
pseudo stratified cell
- all cells im contact with basement membrane
- usually picture of this type of cell looks messy
- e.g. nasal cavity, trachea, bronchi
transitional epithelium
- shape different depending on what state the organ is
- empty bladder vs full
- when full - cells stretch; look more squamous
- when empty - cuboidal appearance
- urinary tract is region where it’s most common
in what 3 ways of glandular epithelia classified?
1) types of secretions
2) structure of gland
3) method of secretion
what are the 2 types of glandular secretions?
1) exocrine
2) endocrine
exocrine glands
- glands that secrete onto the body surface or into passageway connected to the exterior
- e.g. sweat gland
_____ epithelium can be keratinized or nonkeratinized
stratified squamous
keratin - def
tough, fibrous protein component of nails, hair, calluses, and the general integumentary surface
keratinized - def
containing large quantities of keratin
_____ stratified squamous epithelium are tough and water resistant
keratinized
_____ stratified squamous epithelium resist abrasion but must be kept moist
nonkeratinized
what are the 3 types of exocrine glands, based on the secretions they produce?
1) serous glands
- secrete watery solution that usually contains enzymes, such as salivary amylase in saliva
2) mucous glands
- secrete glycoproteins called mucins that absorb water to form slippery mucus (e.g. saliva)
3) mixed exocrine gland
- more than one type of gland cell and may produce both serous and mucus secretions
endocrine gland
-gland that secretes hormones into the blood
what are the two types of glandular structures?
1) unicellular
2) multicellular
unicellular glands
- the cell alone is the entire glandular tissue
- secrete mucins
what are the two types of unicellular exocrine glands?
1) mucous cells
2) goblet cells
multicellular exocrine gland
-when multiple cells combine together to make a gland
what are the 3 methods of glandular secretion?
1) eccrine
2) apocrine
3) holocrine
what is the most common mode of secretion?
eccrine (merocrine) secretion
what are the 3 basic components of CT?
1) cells
2) fibers
3) ground substance
what are the 3 types of CT?
1) CT proper
2) fluid CT
3) supporting CT
what are the main functions of CT?
1) establish structural framework for the body
2) transport fluids and dissolved materials from one region of body to another
3) protect delicate organs
4) support, surround, interconnect other tissue types
5) store energy, especially in lipids
6) defend body from invasion by microorganisms
what are the two types of CT proper
1) loose
2) dense
what are the 3 types of loose CT proper?
1) areolar
2) adipose
3) reticular
what are the 3 types of dense CT proper?
1) dense irregular
2) dense regular
3) elastic
what are the two types of fluid CT
1) blood
2) lymph
what are the two types of supporting CT
1) cartilage
2) bone
what are the 3 types of cartilage?
1) hyaline
2) elastic
3) fibrous
what are the two types of cells in CT proper? Provide examples of each
1) fixed cells (found in loose CT except for melanocytes)
- fibroblasts
- fibrocytes
- fixed macrophages
- adipocytes
- mesenchymal cells
- melanocytes
2) wandering cells (found in dense CT + melanocytes)
- free macrophages
- mast cells
- lymphocytes
- neutrophils and eosinophils
function of fibroblasts
-produce CT fibers
function of fibrocytes
- “activated fibroblasts’
- maintain CT fibres and matrix
function of fixed macrophages
-phagocytize pathogens and damaged cells
function of adipocytes
-store lipid reserves
function of mesenchymal cells
-CT stem cells that can differentiate into other cell types
function of melanocytes
-synthesize melanin
function of free macrophages
-mobile/traveling phagocytic cells (derived from monocytes in the blood)
function of mast cells
-stimulate local inflammation by releasing histamine and/or heparin
function of lymphocytes
- participate in immune response
- some develop into plasma cells that produce antibodies
function of neutrophils/eosinophils
-mobilize during infection or tissue injury
what are the most abundant type of fixed cell
fibroblasts
which 3 types of fibres make up CT proper?
1) collagen
2) reticular
3) elastic
CT proper: collagen fibers
-strong, insoluble protein fibres; most common fibre in CT proper
_____ connect skeletal muscles to bones
tendons
_______ connect bone to bone, or cartilage to cartilage
ligaments
what is the function of areolar tissue
- cushions organs
- provides support but permits independent movement
- phagocytic cells provide defence against pathogens
what is the function of adipose tissue
- provides padding and cushions shocks
- insulates
- store energy
what is the function of reticular tissue
-provides supporting framework
what are the functions of dense regular CT
- provides firm attachment
- conducts pull of muscles
- reduces friction between muscles
- stabilizes relative positions of bones
-e.g. tendon
what are the functions of elastic tissue
- stabilizes positions of vertebrae and penis
- cushions shock
- permits expansion and contraction of organs
-e.g. ligament
what are the functions of dense irregular CT
- provides strength to resist forces applied from many directions
- helps prevent over-expansion of organs
-e.g. deep dermis
name 3 differences between tendons and ligaments
1) tendons have relatively few fibrocytes
2) fibrocytes in tendons are located between bundles of collagen fibers, whereas in ligaments they’re among the bundles
3) in tendons, fibrocytes tend to be more elongated
what are the 3 components of blood
1) RBC (45%)
2) WBC (very small %)
3) platelets
what are cartilage cells called
chondrocytes
chondrocytes live in small chambers known as ______
lacunae
what separates cartilage from surrounding tissues?
perichondrium
what’s the most common type of cartilage? where is it found?
hyaline
-found between connections between ribs and sternum; supporting cartilages along conducting passageways of respiratory tract; articular cartilages covering opposing bone surfaces in synovial joints
what is the weakest type of cartilage?
hyaline
what’s the purpose of hyaline cartilage?
- provides stiff but somewhat flexible support
- reduces friction between bony surfaces
what is the purpose of elastic cartilage?
-provides support, but tolerates distortion without damage and returns to original shape
what is the purpose of fibrous cartilage?
- resists compression
- prevents bone-to-bone- contact
- limits relative movement
table 3.2: comparison of structural features of cartilage and bone
review
osteocyte - def
bone cells responsible for the maintenance and turnover of the mineral content of the surrounding bone
periosteum - def
layer that surrounds a bone, consisting of an outer fibrous and inner cellular region
sarcoplasm - def
cytoplasm of a muscle cell
sarcolemma - def
plasma membrane of a muscle cell
function of skeletal muscle tissue
- moves or stabilizes position of skeleton
- guards entrances and exits to digestive, respiratory, and urinary tracts
- generates heat
- protects internal organs
function of cardiac muscle tissue
- circulates blood
- maintains bp
function of smooth muscle tissue
- moves food, urine, reproductive tract secretions
- controls diameter of respiratory passageways
- regulates diameter of blood vessels
skeletal muscle tissue
- multiple nuclei, peripherally located
- rounded, cylindrical cells, minimal size variation
- striated
cardiac muscle tissue
- single nucleus, centrally located
- short branched cells, moderate size variation
- striated (intercalated discs)
smooth muscle tissue
- single nucleus, centrally located
- short spindle shaped (in longitudinal cross section); considerable size variation
- non-striated
which two basic types of cells make up nervous tissue
1) neurons
- functional cell of NS
2) neuroglia
- support cell for neutrons and NS
