Anatomy/physiology Lecture 2
mucus
a lubricating fluid that is composed of water and mucins and is produced by unicellular and multicellular glands along the digestive, respiratory, urinary, and reproductive tracts
squamous epithelium
cells are flat and white with a disc shaped nucleus
columnar epithelium
cells are taller than they are wide
what are the characteristics of epithelial tissue
cellularity, polarity, attachment, avascularity, innervation, regeneration
transitional epithelium
change shape depending on the state of stretch in the tissue
what are the three categories of connective tissue?
connective tissue proper, supporting connective tissue, fluid connective tissue
lymph
derived from plasma and has no formed elements
holocrine secretion
destroys the cell, which becomes packed with secretions before finally bursting
what are the three embryonic tissue layers?
endoderm, mesoderm, ectoderm
macrophages
engulf damaged cells or pathogens that enter the tissue
examples of exocrine secretions
enzymes entering digestive tract, sweat, and breast milk
gland cells
epithelial cells that produce secretions
what are the 4 basic types of tissues?
epithelial, connective, muscle, nervous
gap junction
essential to coordination of muscle contraction
endo means
inside
epithelia cover ___ and ___ body surfaces
internal, external
apocrine secretion
involves the loss of cytoplasm as well as the secretory product
ecto means
outside
where are endocrine secretions produced?
pancreas, thyroid, pituitary gland
tight junction
prevents the passage of water and solutes between cells
synovial membrane
produces synovial fluid in joint cavities
what are the main functions of epithelial tissues?
protection, selective permeability, secretion, sensation
what are the functions of connective tissue?
protection, support, binding, storage, and transport
antibodies
proteins that destroy invading microorganisms or foreign substances
epithelia functions
provide physical protection, control permeability, provide sensation, produce specialized secretions
what are 3 common types of cell junctions
tight junctions, gap junctions, desmosomes
lymphatic vessels
transport lymph back to cardiovascular system
Hemidesmosomes
resemble half of a spot desmosome and attach a cell to the basement membrane
glands
secretory structures derived from epithelia
Perichondrium
separates cartilage from surrounding tissues
cardiac muscle tissue
short, branched, striated, single nucleus, interconnected by intercalated discs
smooth muscle tissue
short, spindle shaped, non striated, single nucleus
simple epithelium
single layer of cells
what does the mesoderm embryonic layer become?
skeleton, muscle, kidneys, heart, blood
what does the ectoderm embryonic layer become?
skin and nervous system
intercalated dics
specialized attachment sites containing gap junctions and desmosomes
muscle tissue
specialized for contraction
adipose tissue
stores energy, cushions organs, insulates against external environments
dense connective tissue
strong, has fibers (mostly collagen) packed tightly together
exfoliative cytology
study of cells shed or removed from epithelial surfaces
histology
study of tissues
What do connective tissues do?
support
areolar tissue
surrounds and protects, connects epithelium to deeper tissue
cutaneous membrane
the skin that covers the surface of your body
how many different types of cells are in the body?
200
tissues
Collections of specialized cells and cell products that perform a limited number of functions.
ligaments
Connect bone to bone
elastic fibers
Contain elastin, branched and wavy, return to original length after stretching
pseudostratified epithelium
Contains one layer of epithelial cells, but appears to have more than one
mast cells
A connective tissue cell that when stimulated releases histamine and heparin, initiating the inflammatory response,
cartilage
A connective tissue with a gelatinous matrix containing an abundance of fibers
basement membrane
A layer of filaments and fibers that attach an epithelium to the underlying connective tissue
chondocytes
cartilage cells
periosteum
Layer that surrounds a bone, consisting of an outer fibrous and inner cellular region
exocrine secretion
Secretion onto a body surface
what is connective tissue composed of?
cells and extracellular matrix
fibroblasts
The only cells that are always present in connective tissue proper, produce connective tissue fibers and ground substance
cuboidal epithelium
cells are as tall as they are wide, with a spherical nucleus
loose connective tissue
acts as packing material, found in spaces around organs
what is the cause of anencephaly
an incomplete anterior neural tube closure
reticular tissue
anchors epithelial tissues
epithelium
avascular layer of cells that forms a barrier that covers internal/external surfaces
meso means
between, middle
osteocytes
bone cells
What does the neural tube become?
brain and spinal cord (central nervous system)
connective tissue proper
contains collagen fibers, elastic fibers, and reticular fibers
myosin and actin
contractile proteins
what do nervous tissues do?
control
tendons
cords of dense regular connective tissue that attach skeletal muscles to bones
visceral layer
covers external surface of organs
what is the cause of spina bifida
incomplete posterior neural tube closure
fibrocartilage
extremely durable and tough
elastic cartilage
extremely resilient and flexible, forms external flap of external ear, epiglottis, and small cartilages in the larynx
adipocytes
fat cells
why have neural tube defects become less common?
folic acids
connexons
form a narrow passageway that lets small molecules and ions pass from cell to cell in a gap junction
dense irrecular connective tissue
forms organ capsules, bone/cartilage sheaths, deep dermis of skin
dense regular connective tissue
forms tendons and ligaments, collagen fibers run in a single parallel direction
what does the endoderm embryonic layer become?
gut, liver, lungs
elastic dense connective tissue
has the least amount of support
endocrine secretion
hormones, released by gland cells into surrounding tissue fluid
articulations
joints
mucous membranes (mucosae)
line passageways and chambers that communicate with the exterior
serous membrane
line the body's sealed internal cavities of the trunk
parietal layer
lines inner surface of body cavity
serous pericardium
lines pericardial cavity and covers heart
peritoneum
lines peritoneal cavity and covers abdominal organs
skeletal muscle tissue
long, cylindrical, multinucleate cells, striated
reticular fibers
made up of the same protein subunits as collagen fibers, but arranged differently. The least common of the three fibers, thinner than collagen fibers. forms branching, interwoven framework in various organs.
fibrocytes
maintain the connective tissue fibers of connective tissue proper
methods of glandular secretion
merocrine, apocrine, holocrine
Canaliculi
microscopic passageways between cells
stratified epithelium
more than one layer of cells
collagen fibers
most common fiber in connective tissue proper. long, straight, unbranched
merocrine secretion
most common method of secretion, product is released through exocytosis.
hyaline cartilage
most common type of cartilage, tough but flexible. covers breastbone, respiratory tract, and opposing bone surfaces within joints
what do muscle tissues do?
movement
ground substance
unstructured material that fills the space between the cells and surrounds fibers
leukocytes
white blood cells
avascular
without blood vessels
