Chapter 4 Flashcards
artifacts
minor distortions that alter a preserved tissue’s condition. this is why most microscopic structures are not exactly like living tissue
epithelial tissue or epithelium
sheet of cells that covers a body surface or lines a body. 2 forms: covering and lining (lines outer layer of skin, digestive system, respiratory system and organs in ventral body cavity) and glandular (fashions the glands in the body)
functions include: protection, absorption, filtration, excreatoin, secretion and sensory reception
polarity
characteristic of epithelium. all epithelia have an apical surface (upper surface exposed to exterior) and a lower attached basal surface. these two differ and exhibit a polarity. also includes microvilli and basal lamina
microvilli
part of epithelium. fingerlike extensions of membrane that increase exposed surface area. intestinal is brush border
basal lamina
adjacent to basal surface and acts as a selective filter that determines which molecules diffusing can enter the epithelium. connects epethelium to underlying connective tissue
specialized contacts
characteristic of epithelium. epithelial cells fit closely together. tight junctions and desmosomes bind adjacent cells together to help keep things from diffusing in
supported by connective tissue
characteristic of epithelium. the basal lamina and reticular lamina form the basement membrane which reinforces the epithelium sheet and prevents stretching and tearing
avascular but innervated
characteristic of epithelium. epithelium contains to blood vessels (avascular) and is supplied by nerve fibers (innervated).
regeneration
characteristic of epithelium. epithelial cells can reproduce themselves rapidly when some are destroyed. they replace lost cells by cell division
simple squamous epithelia
single layer of flattened cells. diffusion and filtration, protection is not important here. located in kidney, air sac of lungs, heart lining, blood vessels, serosae and lymphatic vessels
simple cuboidal epithelia
single layer of cube cells. secretion and absorption. located in kidney tubules, ducts of smallglands and ovary surface
simple columnar epithelia
single layer of tall cells. secretion and absorption of mucus and enzymes. located in digestive tract, gallbladder and excretory ducts of uterus
stratified squamous epithelia (non keratinized)
protects underlying tissues from abrasion. thick membrane of several cell layers. basal cells are cuboidal/columnar and they do mitosis to replace surface cells. located in the moist linings of esophagus, mouth ad vagina
stratified squamous epithelia (keratinized)
protects underlying tissues from abrasion. thick membrane of several cell layers. basal cells are cuboidal/columnar and they do mitosis to replace surface cells. located in the skin
endothelium
type of simple squamous epithelium. provides slick, friction-reducing lining in lymphatic vessels and in cardiovascular system organs (blood vessels and heart)
mesothelium
type of simple squamous epithelium. in serous membranes, lines the ventral body cavity and covers its organs
pseudostratified columnar epithelium
single layer of cells with differing heights. all start at basemen membrane. located in sperm carrying ducts, ducts of large glands, trachea and upper respratory tract
transitional epithelium
type of stratified epithelia. stetch to store urine. basal cells are cuboidal or columnar, surface cells depends on stretching. located in the uterus or bladder.
gland
one or more cells that make and secrete a product, called a secretion. classified by where they release their product (encorine or exocrine) and their cell number (unicellular, multicellular)
secretion
- product of gland, an aqueous fluid that usually contains fluids
- the process glands go through to make and release this product. glands obtain substances from the blood and transform them chemically into this product
endocrine glands
secrete internally. ductless glands. structurally diverse. they produce hormones (messenger chemicals) that they secrete by exocytosis into extracellular space. hormones travel by blood to target organs and prompt these organs to respond. e.g. pituatary gland, testes, ovaries, thyroid
exocrine glands
secrete externally onto the body surface (skin) or body cavities. they are diverse. unicellular produce mucus and do not have ducts. multicellular produce sweat, oil and have ducts
connective tissue
connects all parts of body together. most abundant and widely distributed primary tissue. 3 main components: ground substance, fibers, and cells. 4 main classes: connective tissue proper (fat and fibrous tissue of ligaments), cartilage, bone and blood.
functions are: 1. binding and supporting, 2. protecting, 3. insulating, 4. storing resserve fuel and 5. transporting substances
ground substance
structural element of connective tissue. acts as a medium for nutrients to diffuse between blood capillaries and the cells. made of fluid, adhesion proteins and proteolycans. fills space between cells
connective tissue fibers
a structural element of connective tissues. these provide support. 3 types of fibers: collagen fibers, elastic fibers and reticular fibers
collagen fibers
type of connective tissue fibers. the strongest and most abundant. stronger than steel. constructed of the fibrous protein collagen
elastic fibers
type of connective tissue fibers. long, thin fibers that form branching networks in the extracellular matrix. made of protein elastin, which stretches and recoils like rubber bands. these are located where elasticity is needed (skin, lungs and blood vessel walls and aorta).
reticular ribers
type of connective tissue fibers. short branching fibers, collagenous fibers that branch extensively and form delicate fibers that surround small BV and support soft tissue of organs (in spleen). abundant where connective tissue is in contact with other tissue types
connective tissue cells
structural element of connective tissues. in extracellular matrix. help in binding, support, insulation, and protection. these exist in immature and mature forms. immature cells have the “-blast” suffix and are active cells that secrete the ground substance. mature cells have the “-cyte” suffix which are less active and maintain the health of the matrix.
other types include fat cells, white blood cells, mast cells and macrophages
mast cells
a type of connective tissue cell. they cluster around blood vessels and detect foreign microorganisms and initiate local inflammatory responses against them and secrete chemicals that mediate inflammation. release histamine
mesenchyme
a common embyonic tissue that gives rise to mature connective tissues. it arises during early weeks of embryonic development and differentiates into all types of connective tissue cells. some of these cells remain and provide a source of new cells in mature connective tissues.
connective tissue proper-loose connective tissues subclass
type of conntective tissue. these have 3 subdivisoins: areolar, adipose and reticular
areolar connective tissue
type of connective tissue proper (loose connective tissue). it is a gel-like matrix with fibroblasts, macrophages, mast cells and WBC and loose arrangement of fibers. it supports and binds tissues, wraps and cushions organs. hold tissue fluids and helps defend against infections and inflammation.
widely distributed under epithelia in body. forms lamina propia of mucous membranes. package organs and surround capillaries
adipose tissue
type of connective tissue proper (loose connective tissue). it is a sparse matrix made of closely packed fat cells (adipocytes). it provides a reserve food fuel, insulation, supports/protects organs. located under the skin in subcutaneous tissue, around kidneys and eyeballs, and in abdomen and breasts.
reticular tissue
type of connective tissue proper (loose connective tissue). limited to certain sites, found in loose ground network. forms soft internal skeleton (stroma) and supports other cells (WBC,mast and macrophages). located in lymphoid organs (lymph nodes, bone marrow and spleen).
connective tissue proper (dense connective tissue)
type of connective tissue proper. this has 3 sub divisions: dense regular connective tissue (often called fibrous connective tissue) and dense irregular connecive tissue and elastic connective tissue
dense regular connective tissue
type of connective tissue proper (dense connective tissue). closely packed parallel collagen fibers that withstand great resistance to being pulled. these are in tendons (attach muscles to bones) and ligaments (bind bones together at joints).most common cell is fibroblast.
dense irregular connective tissue
type of connective tissue proper (dense connective tissue). this withstands tension exerted in many directions because its arranged irregularly. provides structural strength. located at joints and skin and digestive tract. irregularly arranged collagen. main cell type is fibroblast.
elastic connective tissue
type of connective tissue proper (dense connective tissue). allows tissue to recoil after strething. maintains pulsatile flow of blood through arteries. in walls of large arteries, ligaments and walls of bronchial tubes. contains elastic fibers
cartilage
type of connective tissue. stands up to tension and compression. is an intermediate between dense connective tissue and bone. tough but flexible. avascular. 3 types: hyaline cartilage, elastic cartilage and frbriocartilage. has gel matrix and cells inside lacunae. separated from surrounding tissues by a pericardium
hyaline cartilage
type of cartilage. most abundant cartilage in the body. provides support/cushion. Fibers are not normally visible. covers ends of long bones, in the nose, ribs, trachea, larynx. forms most of embryonic skeleton
elastic cartilage
type of cartilage. similar to hyaline cartilage but has more elastic fibers. maintains shape of structure while allowing great flexibility. supports external ear and epiglottis
fibrocartilage
type of cartilage. provides strong support and withstands heavy pressure, very tough. absorb shock. in knee joints and intervertebral discs
bone (osseous tissue)
type of connective tissue. many collagen fibers and osteocytes, supports and protects, lever for moving. stores calcium, marrow inside bones is the site for blood cell formation. highly vascularized
blood
type of connective tissue. red and white blood cells in fluid matrix. transport respiratory gases, nurtients and wastes. located in blood vessels. erythrocyte (RBC) makes up half the volume
muscle tissue
tissues that are highly cellular, well-vascularized and responsible for body movement. cells in these contain myofilaments (cause movement/contraction). 3 types: skeletal, cardiac and smooth
skeletal muscle
type of muscle tissue. attached to bones of the skeleton. pull on bones or skin and cause body movement. also called muscle fibers. voluntary movement. have multiple nuclei and striated. contain myofilament cells
cardiac muscle
type of muscle tissue. in the walls of the heart. its contractions propel blood through blood vessels. they are striated and have only one nucleus. branching cells that fit together tightly are intercalated discs
smooth muscle
type of muscle tissue. no striations. have one nucleus. located in the walls of organs other than the heart. involuntary movement. move food, urine, baby.
nervous tissue
main component of nervous system (brain, spinal cord and nerves). regulates and controls body functions. contains 2 major cell types: neurons and supporting cells. transmits electrical signals via axons. dendrits receive info. this is branching
neurons
type of cells in nervous tissue. highly specialized nerve cells that generate and conduct nerve impulses. branching cells that transmit electrical signals from sensory receptors to effectors (muscles and glands) that control their activity.
cutaneous membrane
organ system consisting of keratinized stratified squamous epithelium attached to a thick layer of connective tissue. it is skin that covers our body
mucous membranes or mucosae
membrane that lines all body cavities open to the outside of the body. e.g. digestion and urogential tracts (these are open to external environment). these are moist membranes. communicate with the exterior of the body
serous membranes or serosae
moist membranes in closed ventral body cavities. made of simple squamous epithelium resting on a loose connective (areolar) tissue. named for their site and organ associations. e.g. pleurae line the thoracic wall and cover lungs, pericardium encloses the heart and peritoneum encloses the abdominopelvic viscera. there is also a serous fluid that provides lubrication between membranes. Adhesions between abdominopelvic organs occur when this is damaged
regeneration
type of tissue repair. this replaces destroyed tissue with the same kind of tissue
fibrosis
type of tissue repair. permanent replacement of normal tissue by fibrous tissue. fibrous connective tissue proliferates (increase in number) to form scar tissue
inflammation
first step of tissue repair. severed blood vessels bleed. inflammatory chemicals are released. local BV become more permeable (allows WBC, clotting proteins, etc) to seep into injured area. clotting occurs and surface dries and forms a scab
organization
second step of tissue repair. clot is replaced by granulation tissue which restores vascular supply. fibroblasts produce collagen fibers that bridge the gap. macrophages eat dead cells. surface epithelial cells multiply and migrate over the granulation tissue
regeneration and fibrosis
third and last step of tissue repair. the fibrosed area matures and contracts, the epithelium thickens. a fully regenerated epithelium that resembles adjacent skin results. there is an underlying area of scar tissue
primary germ layers
one of the first events in embryonic development is the formation of these. they lie on top of each other. they are the ectoderm, mesoderm and endoderm. they will specialize and form the 4 primary tissues: epithelium, nervous tissue, muscle and connective tissue
ectoderm
type of primary germ layer. gives rise to epithelium and nervous tissue
mesoderm
type of primary germ layer. gives rise to epithelium and muscle and connective tissue
endoderm
type of primary germ layer. gives rise to epithelium and inner lining of digestive system
brown fat
warms the body, mainly on babies who cannot shiver
white fat
stores nutrients
edema
caused when areolar connective tissue soaks up excess fluid in an inflamed area
simple squamous epithelium
moves things along quickly, slick and slippery, does absorption. in BV, epicardium and kidneys
simple cuboidal epithelium
does absorption and secretion. lies kidney tubules. in thyroid
simple columnar epithelium
does absorption and secretion. cilia helps propel mucous and lines respiratory tract. non ciliated is in the digestive system (they have microvilli)
stratified squamous epithelium
protects us from abrasion, chemicals, virus. it is keratinized skin. also in esophagus and vagina
goblet cells
important unicellular gland. contains mucin that dissolves in water. produces mucus. golgi bodies are important to this. commonly found wedged between simple columnar epithelial cells and found within pseudostratified columnar epithelium
occluding junction
stops materials from moving between cells across an epithelium.
lamina lucida
A layer of glycoproteins that prevents leakage of materials from connective tissues into epithelia
Germinative cells
divide continually to produce new epithelial cells
fibroblast
most common cell in connective tissue proper. produce fibers in areolar connective tissues and reticular layer of the dermis. also produces collagen and protein. divide to produce mobile cells that repair the dermis. produce granulation tissue to repair skin
macrophages
2 classes: fixed and free. 2 types: neutrophils and eosinophils
Wharton’s jelly
a form of mucous connective tissue
Mesenchymal cells
respond to injury by dividing and differentiating into fibroblasts, macrophages, or other connective tissue cells.
pleura
the serous membrane lining the thoracic cavity
deep fascia
dense connective tissue that surrounds muscles and blends with the tendon
superficial fascia
framework of connective tissue between the skin and underlying muscles is called the
neurons
they conduct a nervous impulse. when mature, they lose the ability to divide. they are separated from one another by synapses. they are composed of a soma and axon.
axons
carries information electrically from one part of the body to another
neuroglia / glial cells
They perform phagocytosis, support neural tissue, supply nutrients to neurons.
dendrites
receive information
brush border
intestinal microvilli
lacuna
small pit found in bone and cartilage
plasma
liquid matrix of blood
tight junction
among epithelial cells lining the digestive tract
stroma
The supportive internal framework of an organ (or gland or other structure), usually composed of connective tissue. can support many free blood cells in lymph nodes, spleen and bone marrow
parenchyma
the functional tissue of an organ as distinguished from the connective and supporting tissue.
merocrine glands
most common and secrete products by exocytosis. produce secretions such as saliva, sweat, digestive enzymes
holocrine glands
accumulate products inside them until they rupture.
apocrine glands
secrete by accumulating their products and pinching off portions of the apex
