170 terms

chapter 4 A&P

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tissues
groups of similar cells that perform a specific function in an organism
histology
the branch of biology that studies the microscopic structure of animal or plant tissues
epithelial tissue
membranous tissue covering internal organs and other internal surfaces of the body
functions of epithelium
1- protection 2 - absorption 3 - filtration 4 - excretion 5 - secretion 6 - sensory reception
what is the specialty of the glands
secretion
apical surface
the side of an epithelial cell that faces the outer body, a body cavity, or the lumen of an internal organ or duct
basal surface
The bottom layer of epithelial tissue that attaches to the basement membrane
apical - basal polarity
cell regions near the surface differ from those near the basal surface both in structure and function
microvilli
projections that increase the cell's surface area
cilia
short structures projecting from a cell and containing bundles of microtubules that move a cell through its surroundings or move fluid over the cell's surface
basal lamina
noncellular, adhesive sheet consists largely of glycoprotiens secreted by the epithelial cells plau some fine collagen fibers.
function of basal lamina
selective filter that determines which molecules dfffusing from the underlying connective tissue are allowed to enter the epithelium
function of basal lamina
acts as a scaffolding alonf which epithelial cells can migrate to repair a wound
specialized contacts
tight junctions, desmosomes, gap junctions
tight junctions
impermiable junctions prevent molecules from passing the the intercellular space
desmosomes
anchoring junctions bind adjacent cells together and help form an internal tension reducing network of fibers
gap junction
commuicationg junctions allow ions and small molecules to pass from one cell to the next foe intercellular communication
reticular lamina
a layer of extrcellular material containing a fine network of collagen fibers that belongs to the underlying connective tissue
innervated
supplied by nerve fibers
avascular
contains no blood vessels
regeneration
as long as epithelial cells recieve adequate nutrition they can replace lost cells by cell division
epithelial name
1st - indicates the number of cell layers present 2nd - describes the shape of the cells
simple epithialia
consist of a single cell layer
simple epithila - location
where absorption, secretion, and filtration occur and a thin epithilial barrier is desirable
stratified epithilia
composed of two or more cell layers stacked on top of each other
stratified epithilia - location
common in high abrasion areas where protection is important, such as skin surface and the lining of the mouth
squamous cells
flat and scalelike
cuboidal cells
box like and approximately as wide as they are tall
columnar cells
are tall and column shaped
nuclear shape
the nucleus is shaped like the cell
simple cuboidal epithelium
function: secretion and absorption
location: kidney tubules, ducts and secretory portions of small glands, ovary surface
simple cuboidal epithelium
simple columnar epithelium
function: absorption, secretion of mucus, enzymes and other substances cilliated type propels mucus (or reproductive cells) by ciliary action
location: nonciliated type lines most of the digestive tract (stomach to anal canal) gallbladder, and excretory ducts of some glands, cilliated varieties line small bronchi, uterine tubes and some regions of the uterus
simple columnar epithelium
pseudostratified columnar epithelium
function: secretion, particularly of mucus, porpulsion of mucus by cillary action
location: noncilliated type in males sperm- carrying ducts and ducts of large galnds, ciliated variety lines the trachea, most of the upper respiratory tract
pseudostratified columnar epithelium
stratified squamous epithelium
function: protect underlying tissues in areas subjected to abrassion
location: nonkeritinized type forms the moist linings of the esophogus, mouth, and vagina - keritanized variety forms the epidermis of the skin, a dry membrane
stratified squamous epithelium
transitional epithelium
function: stretches readily and permits distension of urinary organ by contained urine
location: lines the ureters, urinary bladder and part of the urethra
transitional epithelium
gland
consists of one or more cells that make and secrete aa particular product
secretion
an aqueos fluid that usually contains proteins but there is variation
secretion process
an active process - cells obtain needed substances from the blood abd transform them chemically into a product that is then discharged from the cell
endocrine glands
internally secreting, often called ductless glands because they lose their ducts, produce hormones, structuraly diverse
hormones
regulatory chemicals
exocrine glands
externally secreting, are numerous, excrete product onto body surface or into body cavities - mucous, sweat, oil, salivary glands, liver (secretes bile) pancreas (synthesizes digestive enzymes)
unicellular exocrine galnds
one celled glands - mucus cells and goblet cells
unicellular exocrine galnds (loc)
epithelial linings of the intestinal and respiratory tract amid columnar cells with other functions
unicellular exocrine galnds (fx)
produce mucin - which becomes mucus
mucin
glycoprotein that dissolves in water when secreted - once desolved becomes mucus
unicellular exocrine glands
mucous cells and goblet cells
goblet cells
distorted and look like a goblet
multicellular exocrine glands (desc)
have two basic parts - epthelium derived duct and s secretory unit
overview of tissue types
innervated
supplied by nerve fibers
avascular
contains no blood vessels
basement membrane is formed by
two laminae
shapes of cells
How are stratified tissues named?
cells are named according to the appical layer
simple squamous epithelium
simple squamous epithelium
function: allow passage of materials by diffusion and filtration in sites where protection is not important, secrete lubricating substances in serosae
location: kidney glomeruli, air sacs of lungs, lining of heart, blood vessels, and lymphatic vessels, ling of ventral body cavity (serosae)
endothelium
inner covering - provides a slick, friction - reducing lining in lymphatic vessels and in all hollow orgams of the cardiovascular system - blood vessels and the heart
mesothelium
middlecovering found in serous membranes lining the ventrl body cavity and covering its organs
keritinized
its surface cells contain keratin - a tough protective protein
4 types of connective tissue
1.connective tissue proper (includes fat and fibrous tissue of ligaments) 2. cartilage 3. bone tissue 4. blood
major functions of connective tissue
1. binding and support 2. protection 3. insulation 4. a sblood transportation of substances within the body
common characteristics of connective tissues
1. Mesenchyme as their common tissue of origin 2. Varying degrees of vascularity 3. Cells separated by nonliving extracellular matrix (ground substance and fibers)
mesenchyme
embryonic connective tissue,Gives rise to all other connective tissues, Gel-like ground substance with fibers and star-shaped mesenchymal cells
extracellular matrix
nonliving tissue - allows tissue to bear weight, withstand great tension,and endure abuses such as physical trauma and abrasion
three main elements of connective tissue
ground susbstance, fibers and cells
comparison of connective tissues
ground substance
Medium through which solutes diffuse between blood capillaries and cells,
Components:
Interstitial fluid
Adhesion proteins ("glue")
Proteoglycans
Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid)
Trap water in varying amounts, affecting the viscosity of the ground substance
three types of fibers
1. Collagen (white fibers) 2. Elastic 3. Reticular
collagen fibers
Strongest and most abundant type
Provides high tensile strength
elastic fibers
Networks of long, thin, elastin fibers that allow for stretch
reticular fibers
Short, fine, highly branched collagenous fibers
cell types
cells
Mitotically active and secretory cells = "blasts"
Mature cells = "cytes"
Fibroblasts in connective tissue proper
Chondroblasts and chondrocytes in cartilage
Osteoblasts and osteocytes in bone
Hematopoietic stem cells in bone marrow
Fat cells, white blood cells, mast cells, and macrophages
loose connective tissue
Areolar
Adipose
Reticular
dense connective tissue
Dense regular
Dense irregular
Elastic
connective tissue proper: loose connective tissue,areolar
function: wraps and cushions organs, its macropahges phagocytize bacteria, plays important role in inflamation, holds an dconveys tissue fluid
location: widely distributed under epithelia of body, forms lamina propria of mucus membranes, packages organs surrounds capilaries
connective tissue proper: loose connective tissue,areolar
fibroblasts
connective tissue cells that produce fibrous components of extracellular matrix like collagen and elastin
macrophages
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.
mast cells
a vertebrate body cell that produces histamine and other molecules that trigger the inflammatory response.
hyaluronidase
an enzyme (trade name Hyazyme) that splits hyaluronic acid and so lowers its viscosity and increases the permeability of connective tissue and the absorption of fluids
edema
swelling from excessive accumulation of serous fluid in tissue
lamina propria
A layer of loose connective tissue just deep to the basement membrane
white adipose tissue
Stores nutrients. Found beneath skin. Deposits occur around hard working organs like the heart and lymph nodes.
brown adipose tissue
- a type of fat tissue that has a greater # of mitochondria than the mroe common white adipose tissue; it can waste energy by producing heat
connective tissue proper: loose connective tissue, adipose
function: provides reserve food fuels, insulates against heat loss, supports an protects organs
location: under the skin in the hypodermis, around kidneys and eyeballs, within abdomen and breasts
connective tissue proper: loose connective tissue, adipose
connective tissue proper: loose connective tissue reticular
function: fibers form a soft internal skeleton (stroma) thst supports other cell types including white blood cells, mast cells and macrophages
location: lymphoid orgaans (lymph nodes, bone marrow, and spleen
connective tissue proper: loose connective tissue reticular
connective tissue proper: dense connective tissue, dense regular
function: attaches muscles to bones or to muscles, attaches bones to bones, withstands great tensile stress when pulling force is applied in one direction
location tendons most ligaments aponeuroses
connective tissue proper: dense connective tissue, dense regular
reticular cells
produce reticular fiber stroma (network for other cells)
stroma
internal framework that can support many free blood cells (largely lymphocytes) in lymph nodes the spleen and bone marrow
reticular connective tissue
Connective tissue that contains reticular fibers and cells; used to make the framework of major organs
fibrous connective tissues
3 varities of dense connective tissues have fibers as their prominent element
dense regular connective tissue
Connective tissue made from collagen fibers that run in the same direction (makes tendons and ligaments) parallel to the direction of pull
dense irregular connective tissue
interwoven meshwork in no consistent pattern; forms thick fibrous layer called capsule; provides strength to resist forces applied from many directions; helps prevent overexpansion of organs such as the urinary bladder
elastic connective tissue
A dense connective tissue with elastin being the predominant fibre type; found in the walls of the aorta, vocal cords and ligamenta flava
cartilage
strong connective tissue that supports the body and is softer and more flexible than bone
chondroblasts
cells that make cartilage
chondrocytes
mature cartilage cells - typically found in small groups within cavities called lacunae
hyaline cartilage
translucent cartilage that is common in joints and the respiratory passages
connective tissue proper dense connective tissue dense irregular
function: able to withstand tension exerted in many directions, provides structural strength
location: fibrous capsules of orgaans and of joints, dermis of skin, submucosa of digestive tract
connective tissue proper dense connective tissue dense irregular
connective tissue proper dense connective tissue elastic
function: aloows recoil of tissue following stretching maintains pulsatile flow of blood through arteries aids passive recoil of lungs following inspiration
locations: walls of large arteries; within certian ligaments asociated with the vertebral column, within the walls of the bronchial tubes
connective tissue proper dense connective tissue elastic
cartilage hyaline
function: supports and reinforces, has resiliant cushioning properties, resists comprehensive stress
location: forms most of the embryonic skeleton, covers the ends of the long bonesin joint cavities, form costal cartilage of the ribs, cartilages of the nose, trachea, and larynx
cartilage hyaline
elastic cartilage
Similar to hyaline cartilage but contains elastic fibers. Found in the external ear.
cartilage elastic
function: maintains the shape of a structure while allowing great flexibility
location: support the external ear (pinna) epiglottis
cartilage elastic
fibrocartilage
has a matrix containing strong collagen fibers. found in structures that withstand tension and pressure, such as the pads between the vertebrae in the backbone and the wedges in the knee joint.
cartilage fibrocartilage
function: tensile strength with the ability to absorb comprehensive shock
location: invertebral discs pubic symphisis discs of knee joint
cartilage fibrocartilage
osseous tissue
bone
bone
hard calcified matrix containing many collagen fibers, osteocytes lie in lacunae very well vascularized
bone : osseous tissue
function: bone supports and protects (by enclosing) provide leveres for the muscles to act on stores calcium and other minerals and fat, marrow inside bones is the site ofr blood cell formation (hematopoiesis)
bone : osseous tissue
lamella
a thin membrane that is one of the calcified layers that form bones
blood
red and white blood cells in a fluid matrix
plasma
colorless watery fluid of blood and lymph containing no cells and in which erythrocytes and leukocytes and platelets are suspended
neutrophil
a granular leukocyte, named for the neutral stain of its granules, that fights infection by swallowing bacteria (phagocytosis)
erythrocytes
red blood cells
lymphocytes
the two types of white blood cells that are part of the body's immune system: B lymphocytes form in the bone marrow and release antibodies that fight bacterial infections; T lymphocytes form in the thymus and other lymphatic tissue and attack cancer cells, viruses, and foreign substances.
blood
function: transport of respiratory gases nutrients wastes and other substances
location: contained within blood vessels
blood
nervous system
the brain spinal cord and nerves
neurons
Individual cells in the nervous system that receive, integrate, and transmit information.
axons
a part of a neuron that carries impulses away from the cell body
dendrites
branching extensions of neuron that receives messages from neighboring neurons
nervous system
function: transmit electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity
location : brain spinal cord and nerves
nervous tissue
muscle tissue
long cylindrical multinucliate cells obvious striations
myofilaments
The contractile proteins, actin and myosin, of muscle cells
actin
A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells.
myosin
A protein present in muscle fibers that aids in contraction and makes up the majority of muscle fiber
cardiac muscle
branching striated generally uninucleated cells that interdigitate at specialized junctions (intercalated discs)
smooth muscle
spindle shaped cells with central nucleai, no striations cells, arranged closely to form sheets
skeletal muscle
function: voluntary movement, locomotion: manipulation of the environment, facial expression, voluntary control
location: in skeletal muscles attached to bones or occassionaly to skin
skeletal muscle
cardiac muscle
function: as it contracts, it propels blood into the circulation, involuntary control
location: the walls of the heart
cardiac muscle
smooth muscle
function: propels substances or objects (foodstuffs urine a baby) along internal passageways involuntary control
location mostly in the walls of hollow organs
involuntary muscle
controlled by the autonomic nervous system
voluntary muscle
muscles that operate under your control
smooth muscle
cutaneous membrane
skin; covers the surface of the body; consists of statified epithelium and a layer of areolar tissue reinforced by underlying dense irregular connective tissue
mucous membrane
the layer of epithelial tissue that covers internal surfaces of the body and that secretes mucus
serous membrane
thin layer of tissue that covers internal body cavities, the cells of which secrete a fluid that keeps the membrane moist
lamina propria
A layer of loose connective tissue just deep to the basement membrane
pleura
the thin serous membrane around the lungs and inner walls of the chest
pericardium
a double-layered serous membrane that surrounds the heart
peritoneums
The serosa covering the abdominopelvic cavity and viscera.
steps of tissue repair
1. regeneration 2. fibrosis
regeneration
growth anew of lost tissue or destroyed parts or organs
fibrosis
proliferation of fibrous connective tissue called scar tissue
inflamation
Release of inflammatory chemicals
Dilation of blood vessels
Increase in vessel permeability
Clotting occurs
inflamation sets the stage
• Severed blood vessels bleed and inflammatory chemicals are released.
• Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins and other plasma proteins to seep into the injured area.
• Clotting occurs; surface dries and forms a scab.
steps in tissue repair
Organization and restored blood supply
The blood clot is replaced with granulation tissue
Epithelium begins to regenerate
Fibroblasts produce collagen fibers to bridge the gap
Debris is phagocytized
Organization restores the blood supply:
• The clot is replaced by granulation tissue, which restores the vascular supply.
• Fibroblasts produce collagen fibers that bridge the gap.
• Macrophages phagocytize cell debris.
• Surface epithelial cells multiply and migrate over the granulation tissue.
Regeneration and fibrosis
The scab detaches
Fibrous tissue matures; epithelium thickens and begins to resemble adjacent tissue
Results in a fully regenerated epithelium with underlying scar tissue
Regeneration and fibrosis effect permanent repair:
• The fibrosed area matures and contracts; the epithelium thickens.
• A fully regenerated epithelium with an underlying area of scar tissue results.
Primary germ layers:
ectoderm, mesoderm, and endoderm
primary germ layers
Formed early in embryonic development
Specialize to form the four primary tissues
Nerve tissue arises from ectoderm
Muscle and connective tissues arise from mesoderm
Epithelial tissues arise from all three germ layers
16 day old embryo
ectoderm -mesoderm - endoderm
epithelium
nervous tissue from ectoderm
muscle and connective tissue - mostly from mesoderm
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