Anatomy Exam 2

transcription

transcription

the process of copying genetic instructions from DNA to RNA

involves RNA polymerase

RNA polymerase

binds to the DNA and assembles the RNA

translation

converts the language of nucleotides into the language of amino acids; triplet code on the mRNA is converted to the language of amino acids

involves mRNA, tRNA, and ribosomes

occurs in three steps: initiation , elongation, and termination

messenger RNA

carries the genetic code from the nucleus to the cytoplasm

transfer RNA

binds free amino acids in the cytosol and delivers them to the ribosome to be added to a growing protein chain

glands

one or more cells that make and secrete a particular product; derived from epithelium

substances are secreted into ducts, onto surfaces, or into the blood

endocrine glands

secrete their product into the interstitial fluid and from there into the bloodstream; ductless

exocrine glands

secrete their products into ducts that empty onto a surface or into a lumen; ducted

cutaneous membrane

largest membrane of the body; keratinized stratified squamous epithelium with a dense irregular connective tissue layer

dry membrane - exposed to the air; skin

serous membrane

lines closed body cavities; simple squamous epithelium on a layer of areolar connective tissue

double layers with a thin layer of fluid in between

mucous membrane

lines body cavities that open to the outside; epithelium on a layer of areolar connective tissue and sometimes a layer of smooth muscle

wet membrane - surface remains moist; digestive, urinary, and reproductive tracts

synovial membrane

line synovial joints; no epithelial layer, just connective tissue

lubricates the joint, provides nutrients for cartilage and removes waste

stratum basale

most deep layer of the epidermis; a single layer of cuboidal to low columnar keratinocytes resting on the basement membrane; stem cells, melanocytes, and tactile cells

stratum spinosum

thickest stratum of the epidermis; several layers of keratinoctyes; deepest cells continue dividing, but as they’re pushed farther upward, they cease; dendritic cells

stratum granulosum

layer of the epidermis; three to five layers of flat keratinocytes; more in thick skin than in thin skin; dendritic cells

stratum lucidium

layer of the epidermis; thin zone of densely packed keratinocytes; only seen in thick skin

stratum corneum

most superficial layer of the epidermis; durable surface layer; consists of up to 30 layers of dead keratinized cells

papillary layer

layer of the dermis; thin zone of areolar tissue in and near the dermal papillae

reticular layer

deepest and thickest layer of the dermis; consists of dense irregular connective tissue

epidermis

a keratinized stratified squamous epithelium; five cell types and four to five layers

dendritic cells

immune cells that originate in the bone marrow but migrate; found in the stratum spinosum and stratum granulosum

tactile cells

receptors of touch; stratum basale

melanocytes

synthesize varieties of melanin; found in the stratum basale

stem cells

undifferentiated cells that divide and give rise to the keratinocytes; found in the stratum basale

keratinocytes

great majority of epidermal cells; synthesize keratin

dermis

connective tissue; two layers

sebaceous glands

produce an oily secretion called sebum; usually open into a hair follicle or directly onto the skin surface

ceruminous glands

modified apocrine glands found only in the external ear canal; yellow, waxy secretion combines with sedum and dead epidermal cells to form cerumen; coiled, simple tubular glands with ducts leading to hair follicles or the skin surface of the ear canal

apocrine sweat glands

scent glands that respond especially to stress and sexual stimulation; large lumen and ducts lead into nearby hair follicles

eccrine sweat glands

cool the body; simple tubular gland with a twisted coil in the dermis or hypodermis, and a coiling duct leading to a sweat pore on the skin surface

bone tissue

a connective tissue in which the matrix is hardened by the deposition of calcium phosphate and other minerals

function: support, protect, movement, RBC production, fat storage, mineral homeostasis

compact bone

outer shell of dense white osseous tissue; encloses the medullary cavity

spongy bone

loosely organized form of osseous tissue; at the ends of the bone

osteogenic cells

stem cells that develop from embryonic mesenchyme and then give rise to most other bone cell types

osteoblasts

bone forming cells that synthesize the organic matter of the bone and then promote its mineralization

osteocytes

former osteoblasts that have become embedded in the matrix they deposited

osteoclasts

bone dissolving cells on the bone surfaces

intramembranous ossification

produces the flat bones of the skull, most of the clavicle, and part of the mandible

endochondral ossification

development of a bone from a preexisting model composed of hyaline cartilage

bone elongation and widening

elongation: the epiphyseal plate consists of typical hyaline cartilage in the middle, with a transitional zone on each side where cartilage is being replaced

widening: appositional growth (deposition of new tissue at the surface)

bone remodeling

collaborative action of osteoblasts and osteoclasts that removes the matrix and gets rid of unnecessary mass (done by osteoclasts) and deposits new bone tissue and thickens it (done by osteoblasts)

calcitonin (calcium homeostasis)

secreted when the blood calcium concentration rises too high, and it lowers the concentration by osteoclast inhibition and osteoblast stimulation

parathyroid hormone (calcium homeostasis)

secreted when the blood calcium concentration is low, and it raises the calcium level by osteoclast stimulation, osteoblast inhibition, promoting urinary phosphate excretion, and inhibiting urinary calcium excretion

articulation

any point where two bones meet

joint functionality

synarthrosis, amphiarthrosis, or diarthrosis

joint structure

fibrous, cartilaginous, or synovial

fibrous joint - synarthrosis

a point at which adjacent bones are bound by collagen fibers that emerge fom one bone, cross the space between them, and penetrate into the other; three kinds - sutures, gomphoses, and syndesmoses

sutures

fibrous joint; immobile or slightly mobile; closely bind the bones of the skull to each other

gomphoses

fibrous joint; the attachment of a tooth to its socket

syndesmoses

fibrous joint; binds two bones by relatively long collagenous fibers

cartilaginous joint - amphiarthrosis

a point where two bones are linked by cartilage; two kinds - synchondroses and symphyses

synchondroses

cartilaginous joint; a joint in which the bones are joined by hyaline cartilage

sympheses

cartilaginous joint; a joint in which the bones are joined by fibrocartilage

synovial joints - diarthrosis

a point where two bones are separated by a narrow, encapsulated space filled with lubricating synovial fluid; relatively mobile joints; have accessory structures; six kinds - hinge, plane, condyloid, ball and socket, pivot, and saddle

tendons

a strip or sheet of tough collagenous connective tissue that attaches a muscle to a bone

ligament

a strip or sheet of tough collagenous connective tissue that attaches one bone to another

angular movements

movements that change the angle between two bones/structures, or between a bone and a midline

ex: flexion, extension, lateral flexion, abduction, adduction, circumduction

rotation movements

movements where a bone/structure rotates around its long axis or around a fixed

ex: rotation, circumduction, supination, pronation

gliding movements

movements where a bone/structure slides in the same plane

flexion

a movement that decreases a joint angle

extension

a movement that straightens a joint

hyperextension

a movement that extends a joint beyond the zero position

abduction

the movement of a body part away from the midline of the body

adduction

the movement of a body part back toward the midline

elevation

a movement that raises a body part vertically

depression

a movement that lowers a body part vertically

protraction

the anterior movement of a body part

retraction

the posterior movement of a body part

circumduction

a movement where one end of the appendage remains relatively stationary and the other end is moved in a circle

rotation

a movement in which a bone spins on its longitudinal axis

supination

a movement that turns the palm to face anteriorly or upward

pronation

a movement that turns the palm to face posteriorly or downward