Week 3: Ch 4 - tissues, glands and membranes

tissues

groups of cells similar in structure arranged in a characteristic pattern and specialized for the performance of specific tasks

histology

study of cells; shows that the form, arrangement and composition of cells in diferent tissues account for their properties

stem cells

unspecialized precursors to all tissue

can divide repeatedly, can become specialized

what are 2 characteristics of stem cells?

embryonic stem cells, adult stem cells

what are 2 types of stem cells?

embryonic stem cells

found in early embryos, source of all body cells, can potentially differentiate into any cell type

adult stem cells

found in babies, children and adults; remain in body after birth; can differentiate into different cell types of their tissue of origin; assist with growth and repair

epithelial, connective, muscle, nervous

what are the 4 main tissue groups?

epithelium tissue

forms protective covering for body and organs; forms membranes and ducts; lines body cavities and hollow organs

squamous

flat and irregular

cubodial

square

columnar

long and narrow

simple

single cell layer

stratified

multiple cell layers

pseudostratified

appears multi-layered but is not

transitional

capable of great expansion and returning to its original state

single cell layer

allows materials to pass from one system to another

multiple cell layers

provide protection in areas of subject to wear and tear

glands

produce a chemical secretion necessary for normal body functioning

exocrine glands, endocrine glands

what are the 2 types of glands?

exocrine glands

have a duct associated with it; duct is a passageway that allows the secretion to be emptied directly into the location where the secretion is to be used

sweat and salivary glands, lacrimal glands

what are some examples of exocrine glands?

endocrine glands

ductless glands; secretion is deposited directly into surrounding tissue fluid then absorbed by bloodstream and carried to the region in which it is to be used (target tissues); secretes hormones

adrenal glands, pituitary, thyroid

what are some examples of endocrine glands?

connective tissue

supporting fabric of entire body; contains large amounts of matrix between cells

circulating CT, generalized CT

what are the 2 types of connective tissue?

circulating connective tissue

cells are in a liquid matrix; blood, lymph; located in blood vessels and lymphatic vessels

generalized connective tissue

provides support and protection; denser (tendons, ligaments); widely distributed and not highly specialized

bone and cartilage

what is an example of structural connective tissue?

loose connective tissue

soft matrix; provides support and protection

dense connective tissue

firm matrix with large numbers of collagen and elastic fibers; provides protection, support, flexibility and attachment

cartilage

strong and flexible with firm matrix; provides protection, structure, shock absorption and elasticity; chondrocytes

bone

made of osseous tissue, similar to cartilage in its cellular structure; solid matrix hardened with mineral salts; gives support, structure and protection; works with muscles to produce movement

skeletal muscle

voluntary control; works with tendon and bones to move the body; striated, multinucleated cells

cardiac muscle or myocardium

involuntary control; forms the bulk of the heart wall; contains intercalated disks

smooth muscle or visceral muscle

involuntary; forms the walls of the viscera or organs of the ventral body cavities

brain

center of all activity within the body

nerves

connects each structure in the body to the brain; come from all over the body and feeds into the spinal cord

spinal cord

communicates with the brain

neuron, neuroglia

what are two cell types of nervous tissue?

neuron

basic unit of nervous tissue; transmit nerve impulses to and from the cell body

dendrites

carries messages to the nerve cell body

axons

carries impulses away from the nerve cell body

neuroglia

specialized cells that support and protect nervous tissue; protects the brain from harmful substances, get rid of foreign organisms and cellular debris, form myelin sheath around axons; do not transmit nerve impulses

membranes

thin sheets of tissue; cover surfaces, serve as dividers, line hollow organs or body cavities, anchor organs, secrete lubricants to ease the movement of organs

epithelial membranes, connective tissue membranes

what are the 2 main categories of membranes?

serous membranes

lines body cavities and cover internal organs

mucous membranes

lines tubes and ducts that open to outside of the body

cutaneous membrane

outer layer of keratinizing, stratified squamous epithelium, inner layer of dense CT

serous membranes

lines body cavities and cover internal organs; do not connect to the outside of the body; secretes a thin, lubricating fluid

mesothelium

thin epithelium of serous membrane, smooth, glistening

parietal layer

the layer attached to the wall of a cavity or sac

visceral serous layer

membrane attached to the organs

potential space

area between the layers of serous membranes

pleurae, serous pericardium, peritoneum

what are 3 types of serous membranes?

pleurae

parietal layer lines the thoracic cavity; visceral layer covers the lungs

serous pericardium

parietal layer lines the pericardial sac; visceral layer covers the heart

peritoneum

parietal layer lines the abdominal cavity wall; visceral layer covers abdominal organs

mucous membranes

secrete mucus; line tubes and ducts that open to outside of the body; varies in structure and function

synovial membranes

line joint cavities, lubricates joints; line small cushioning sacs near joints called bursae

fascia

fibrous bands or sheets that support organs and hold them in place

benign tumors

do no invade other tissues or spread; often encapsulated; cells appear similar to normal cells; can cause harm, depending on size and location

malignant tumors

can cause death; spreads to neighbouring tissues or to different parts of the body; reproduce quicker than normal cells; appear different from parent cells

carcinoma

most common cancer; originates in epithelium

sarcoma

can be found anywhere; originates from CT