Ch 5 Tissues Flashcards
What is a tissue?
a group of cells that are similar in structure and perform a common function
What does extracellular mean?
outside of the cell
What are the 4 major types of tissues and what are their functions?
epithelial - cover and line
connective - support and bind
nervous - control and coordinate
muscle - movement
What is histology?
the study of tissues
What is epithelial tissue?
sheet of cells that covers a body surface or lines a body cavity
How does epithelial tissue occur in the body?
covers and lines epithelium
glandular epithelium
What are some of the epithelial characteristics?
always has a free (apical) surface - exposed to outside or free internal space (lumen)
underside (basal surface) attached to connective tissue by basement membrane
avascular - no blood vessels
innervated - has nerve supply
divide readily - easy to repair/replace
tightly packed - good barrier
other functions - secretion, absorption, excretion, and sensory reception
What are the epithelial functions?
cover and line - outside on skin
secretion - spit out the good stuff
absorption
excretion - spit out the bad stuff
diffusion
What does the 2 part naming system consist of?
First name (# of cells; simple or stratified) + second name (cell shape; squamous, cuboidal, or columnar)
What is the difference between simple and stratified?
simple - single cell layer
stratified - more than one layer
What is the difference between squamous, cuboidal, and columnar?
squamous - flat
cuboidal - cube
columnar - elongated
What is simple squamous epithelium?
Appearance - single layer of thin and flat cells; looks like a fried egg from the top
Location - lining of blood vessels and air sacs (alveoli) of lungs
Function: diffusion (thin), secretion, filtration
What is simple cuboidal epithelium?
Appearance - cube - shaped cells; round nuclei
Location - the lining of kidney tubules, covers surface of ovary, lens of eye; ducts of glands
Function - secretion and absorption
What is simple columnar epithelium?
Appearance - cells are elongated, ciliated or non - ciliated, nuclei at same level, goblet cells secrete mucus
Location - in small bronchial (lungs) and uterine tubes
Function - absorption of nutrients from digested food, secretion, protects underlying tissue
What is pseudostratified columnar epithelium?
Appearance - all cells on basement membrane, but very in height; nuclei at different levels
Location - ciliated with goblet cells in upper respiratory, nonciliated in sperm and ducts of some glands
Function - secretion (mucus) and absorption
What is stratified squamous epithelium?
Appearance - several layers of cells, flat on top
Location - keratinized epidermis of the skin, water - proofing; nonkeratinized lining of mouth, vagina, esophagus and tongue
Function - protection from abrasion
What is stratified columnar epithelium?
Appearance - rare, several cell layers, basal cells cuboidal, top cells columnar
Location - small amounts in male urethra and salivary glands
Function - protection and secretion (mucus)
What is transitional epithelium?
Appearance - apical cells may be domed or squamous like depending on whether bladder is full or empty
Location - lining of urinary organs
Function - stretches
What is glandular epithelium?
Gland - one or more cells that produce and secrete substances into ducts or body fluids
What is the difference between exocrine and endocrine glands?
exocrine - secrete into ducts that open onto some internal or external surface
endocrine - secrete products into tissue fluid or blood
What are exocrine glands?
Secretions include sweat, mucus, oil, ear wax, and digestive enzymes
Examples: sweat gland and salivary glands
Unicellular (goblet cells) or multicellular (sweat gland, salivary glands)
Divided into merocrine, apocrine, and holocrine
What is merocrine?
watery product released by exocytosis
What is apocrine?
product and portion of cell pinch off; a piece of cell
What is holocrine?
entire cell with product disintegrate; whole cell
What are endocrine glands?
Ductless glands
Secretions enter the extracellular fluid and then directly diffuse into the bloodstream
Secretions are called hormones
Examples: pituitary, thyroid, adrenal
What are hormones?
they regulate many metabolic and physiological functions to maintain homeostasis
What is connective tissue?
most common tissue, amount varies by organ
What are the 4 main classes of connective tissue?
Connective tissue proper
Cartilage
Osseous (bone)
Blood
What are the functions of connective tissues?
binding and support
protection
insulation
transportation of substances within body (blood)
What are the common characteristics of connective tissue?
All from the same embryonic tissue (mesenchyme)
Mainly composed of nonliving extracellular matrix; allows tissue to bear weight, withstand tension, endure abuses
What are the structural parts of connective tissue?
ground substance
fibers
cells - very diverse
What is the areolar connective tissue ground substance?
supports cells, binds them together and provides a medium through which substances are exchanged between the blood and cells
may be watery (blood) –> thick gel (cartilage) –> hard (bone)
fibers embedded within make it less pliable
What are the areolar connective tissue collagenous fibers?
collagen; extremely strong; crosslinked fibers banded together; ligaments and tendons
What are the areolar connective tissue elastic fibers?
made of resilient elastin (rubberlike protein); weaker than collagenous but stretch and snap back easily; vocal cords, skin, blood vessel walls
What are the areolar connective tissue reticular fibers?
fuzzy nets of delicate fibers; to collagen but extra fine; around capillaries and soft organ tissue
What are the 6 connective tissue cell types and functions?
Fibroblasts - secrete matrix
Macrophages - perform phagocytosis
Plasma cells - secrete antibodies
Mast cells - produce histamine in reaction to foreign invaders –> inflammatory response
Adipocytes - store fat
White blood cells - migrate from blood in response to infections
What are the connective tissue classifications?
Connective tissue proper - loose connective tissue (areolar, adipose, reticular) and dense connective tissue (dense regular, dense irregular, elastic)
Cartilage
Bone - cover with skeletal
Blood - cover with cardiovascular
What is loose connective tissue areolar?
gel like matrix
cells = fibroblasts
all three fiber types
wraps and cushions organs
holds tissue fluid
attaches skin to underlying tissue
What is loose connective tissue adipose?
nucleus pushed to side by large fat droplet
spare source of fuel for body
insulation
support for organs
What is loose connective tissue reticular?
similar to areolar, but only has reticular fibers
found in: lymph nodes, bone marrow, and spleen only
What is dense regular connective tissue?
Found in tendons and ligaments
Structure is parallel collagen fibers and fibroblasts
What is dense irregular connective tissue?
Irregular arrangement of collagen fibers
Can withstand tension in many directions
Dermis of the skin + fibrous capsules of joints and organs
What is elastic connective tissue?
High percent elastic fibers
Found where recoil of tissues is critical
What are the 3 types of cartilage?
Hyaline
Elastic
Fibrocartilage
What are chondrocytes?
they do not divide often
What is hyaline cartilage?
Cells: chondrocytes in lacunae
Appearance: glassy white/pink with “eyes”, many collagen fibers but they don’t show up against matrix
Functions: resilient, supports and reinforces, template for developing bone
Locations: embryonic skeleton, costal cartilage of ribs, end of nose, trachea, vocal cords
What is fibrocartilage?
Appearance: thick collagen fibers run in parallel
Function: absorbs shock well
Location: intervertebral and knee discs
What is elastic cartilage?
Appearance: like hyaline, but has threadlike elastic fibers in matrix
Function: provides shape and flexibility
Location: external ear
What is a bone?
Hard calcified matrix
Cells: osteocytes in lacunae
Good vascular supply
Functions: supports and protects, levers for movement, stores calcium, phosphorus, marrow is site for blood cell formation
What is blood?
Appearance: red and white blood cells in fluid matrix (plasma)
Function: transport of gases, nutrients, wastes
What is an epithelial membrane?
it consists of an epithelial layer overlying a connective tissue layer
What are mucous membranes?
lines cavities that open to the exterior such as the GI tract, oral, nasal; moist
What are serous membranes?
lines closed cavities and covers the organs in the cavities (like liver,heart, lungs, etc.)
What are cutaneous membranes?
the skin
What are synovial membranes?
they line joint cavities
How many cell types are in the nervous tissue? Name them.
2
Neuron and Neuroglia
What is a neuron?
generate and conduct nerve impulses; cytoplasmic processes
What is neuroglia?
nonconducting; support, insulate, protect
ATUW - adip
fat
ATUW - chondr
cartilage
ATUW - cyt
cell
ATUW - epi
upon
ATUW - glia
glue
ATUW - inter
between
ATUW - macr
large
ATUW - os
bone
ATUW - pseud
false
ATUW - squam
scale
ATUW - strat
layer
