Anatomy Exam 2

Identify and describe the events of protein synthesis

• Transcription

Bases on DNA are transcribed to corresponding bases on a strand of RNA

RNA is modified, then leaves the nucleus to direct actual building of the

protein in the cytosol

Identify and describe the events of protein synthesis

• Translation

Triplet code on the mRNA is converted to the “language” of amino acids

mRNA interacts with other kinds of RNA to build a protein (or strand of amino acids)

What are the beads on a string in DNA/chromosomes

condensed chromosomes make loops that attatch to a protein scaffold

string of nucleosomes coil to from 30nm in diameter

the nucleosomes: DNA winds around a histone core to make a “bead”

DNA is the string and histones are the beads

what proteins help organize DNA

histones

3 BASE ‘TRIPLET’ =

1 amino acid

Protein synthesis is directed by

genetic info or DNA in the nucleus

in protein synthesis 3 steps

DNA —> RNA —> Protein

what are 2 arrows in protein synthesis

DNA —> RNA —> protein

1st transcription DNA—> RNA

2nd translation RNA —> protein

how is mRNA made in transcription

initation phase

DNA is unziped by enxayme then RNA polymerase attaches to the promoter sequence

how is mRNA made in transcription

elongation phase

RNA polymerase dose complmentary base pairing of free ribonucleotides with exposed bases of DNA and they are H-bonded together. Pre-mRNA is made from genes until it reads the terminator sequence

how is mRNA made in transcription

termination phase

RNA polymerase reads the terminal sequence, and newly formed premRNA strand is released from DNA, and transcription is complete

DNA twists itself

how is RNA similar to DNA 1

both have Sugar phosphate “backbone” with nitrogen-containing bases

how is RNA differnet from DNA 3

Uracil replaces thymine as the nitrogen-containing base

Ribose replaces deoxyribose as the sugar in the “backbone”

RNA is always found as a single strand*

define T-RNA

transfer RNA

Picks up amino acids in the cytosol and brings them to the ribosome for

polypeptide synthesis

uses ATP to pick up amino acids

define R-RNA

ribosomal RNA

Makes up part of the ribosome

define M-RNA

messenger RNA

The “copy” of the DNA sequence that travels to the ribosome and directs

protein synthesis

define template vs coding strand

template strand: DNA strand that RNA polymerase runs along

coding strand: strand of DNA that is left alone which is complementary to the template strand and the same as the new mRNA (besides T will be U)

what direction dose RNA polymerase run

what direction is mRNA made

reads: 3' to 5' direction,

mRNA should be read: 5' to 3'

Exons vs Introns

Exons will be translated into protein and are spliced together (EXported out of the nucleus): uncrease flexibity of how many protein one gene can make because can mix thier order

Introns will be removed before translation (stay IN the nucleus and code for ncRNA): are snipped and deleted

after premRNA is transcribed, what happens to amke mRNA

Exons are spliced together, and Introns are snipped and deleted by the snRNP enzyme with ATP

introns may __ and _

regulate gene expression and promote alternative splicing

what are parts of tRNA

colverleaf model with anticodon at bottom and amino acid accpetor end at top

what are parts of rRNA

A(attach) P(protein) E(exit )site

with smaller subunit on bottom and larger subunit on top

what are names of A P site

Aminoacyl

Peptidyl

what are parts of mRNA

start codon (AUG)

codons

stop codon (UAA)

steps of translation

mRNA comes out of the nucleus and then loops into a ring

Initiator tRNA attaches to a start codon AUG with anticodon UAC

Ribosome subunits sandwich onto the mRNA, with the larger subunit on top and the smaller on the bottom, with initiator tRNA in the P site

tRNA grabs amino acids from a pool of free amino acids and delivers them to rRNA (ATP??)

amino acid connected to initiator tRNA via its anticodon is added to the P site of rRNA

another amino acid connected to tRNA via its anticodon is added to the A site of rRNA

The amino acids in the P and A site from a peptide bond and are now only connected to the A-site tRNA

then A site tRNA moves to P site so chain in coming out of the P site

Initiator tRNA that was in the P site moves to E and exits the rRNA to be used again

This cycle keeps happening till the ribosome reaches the stop codon on mRNA, for which there is no tRNA for?

then lager and small subunits dissociate and are at end of mRNA circle so can quickly come back together to make same protein agian

Then proteins fold in the rough ER and leave in a vesicle

____ on the template strand of DNA

base triplets

And these are the same as the anticodons(besides U instead of T)?

And these are complementary to the base triplets of mRNA

columnar epithelial found in

lining of small intestine and stomach b/c they help absorb nutrients

simple squamous epithelial found in

skin

gas exchange

where is hyaline cartilage

On ends of long bones, where slippery is good

(chondrocytes and lots og glassy matrix)

(connective)

Glands are derived from ____

epithelium

Glands are …

one or more cells that make and secrete a particular product (therefore, some glands are single- celled(goblet) and some glands are multi-cellular)

Substances are secreted into ducts(exocrine), onto surfaces(sebasous), or into the blood(endocrine/hormones)

what do goblet cells do

Release mucus into epithelial tissues

Branch off of the lumen into epithelial tissue to release mucus into cells

Endocrine glands

Endocrine glands secrete their products into the interstitial fluid and, from there into the bloodstream; Endocrine glands are DUCTLESS; the most common example of endocrine secretions are hormones

exocrine glands

Exocrine glands secrete their products into ducts that empty onto a surface or into a lumen; Exocrine glands are DUCTED; ex: sebaceous gland on hair follicles that start in the dermis and end in epidermis/outside

how do sebaceous glands work

exocrine

release sebum into hair shaft

sebum: oily substances that softens, and waterproof hair

can ducted exocrine glands be complex

yes

ex: compound or branched ducts

Identify glands based on their function

eccrine

exocytosis where secretory vesicles release their contents into a lumen

ex: salivary galnds

apocrine

Secretion of contents by pinching off of a vesicle

includes part of membranse and the secretory contents

takes part of cell but cell is still alive

ex: mammary glands

holocrine

basal cells mitoisis pushes up dying cells into top of the gland capsule, and the dead cells are shed off as part of the secretion

Disintegrating cells become the secretion and are released

ex: sebaceous glands

Describe the general structure of cutaneous membranes

Covers the body-skin

Keratinized stratified squamous epithelium with a dense irregular connective tissue layer (epidermis and dermis)

“dry” membrane, meaning that it is exposed to the air

Epithelial and connective

Epithelial is KERATINIZED STRATIFIED SQUAMOUS EPITHELIUM

secretions?? sebum???

Describe the general structure of serous membranes

Lines closed body cavities

surrounds organs in motion that do not open to the outside: Pleura(lungs), pericardium(heart), peritoneum(digestive)

Simple squamous epithelium (endothelium or mesothelium) on a layer of areolar connective tissue with a thin layer of serous fluid between

DOUBLE LAYERS with serous fluid between

Describe the general structure of mucous membranes

Line body cavities that open to the outside (urinary, digestive system(mouth))

“wet” because the surface remains moist, bathed by secretions of the epithelium or some other substance (ie, urine)

Layers: mucus, epithelium(can be stratified???), lamina propria (areola connective tissue)

synovial membrane

Line synovial joints that do not open to the outside: joints

Not a true membrane because there is no epithelial layer

Synovial fluid lubricates the joint, provides nutrients for cartilage and removes waste

makes joints movable

Synoviocytes secrete synovial fluid into areolar connective tissue that also has adipocytes

dose not have epithelium??

Identify the tissue types present in skin (in both epidermis and dermis)

Epidermis: Keratinized, stratified squamous epithelium (Many cells in close

proximity; Organized in distinct cell layers)

Dermis: Connective tissue; Papillary region is areolar connective tissue; Reticular region is dense irregular

is the epidermis vascular? innervated?

no its avascular

yes innervated

Describe the layers of the epidermis, and the cells present in each layer

stratum corneum

** stratum lucicium

stratum granulosum

stratum spinosum

stratum basale/germinativum

stratum corneum

flat, dead, membrane-like sacs filled with keratin and glycolipids in the extracellular space

shed off regulary

gives protection\

kerotin envolopes

stratum lucidium

clear layer only found in thick skin

keratinocytes that compose the stratum lucidum are dead and flattened

cells are densely packed with eleidin, a clear protein, derived from keratohyalin, which gives these cells their

transparent

stratum granulosum

keratinocytes are flattened and, organelles are deteriorating and the cytoplasm is full of lamellar granules(release lipids) and keratohyaline granules what help with waterproofing

line of where cells are alive(below) or dead(above and within) cells diy here because they are too far away from the dermis vasuclarture that being oxygen and nutrients and wast removal

stratum spinosum

keratinocytes have thick bundles of intermediate filaments made of pre-keratin

Contains dendritic/Langerhans cells

spiny in appearance due to the protruding cell processes that join the cells via a structure called a desmosome.

keratinocytes in the stratum spinosum begin the synthesis of keratin and release a water-repelling glycolipid that helps prevent water loss from the body, making the skin relatively

waterproof.

stratum basale/germinativum

keratinocytes are actively mitotic pushing up cells to die and be part of upper layers

Contains melanocytes and Merkel cells and melanin granules form an umbrella

bond to the dermis via intertwining collagen fibers, referred to as the

basement membrane.

has dermal papilla

has basal cell

what is a basal cell

cuboidal-shaped stem cell that is a precursor of the keratinocytes of the epidermis.

A finger-like projection, or fold, known as the ___ is found in the superficial portion of the dermis.

and benfit

dermal papilla

increase the strength of the connection between the epidermis and dermis; the greater the folding, the stronger the connections made

cells in epidermis

keratinocytes: most common in all the layers; is a cell that manufactures and stores the protein keratin.

dendritic/langerhans cells: in the stratum spinosum between keratinocytes and part of the immune system and macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer

merkel/tacitle cells: sensory cells that connect to sensory nerve endings; cells are especially abundant on the surfaces of the hands and feet.

melanocytes: make melanin to distribute to keratinocytes by vesicles; for hiar and skin color and protection for UV rays

what is Keratin

intracellular fibrous protein that gives hair, nails, and skin their hardness and water-resistant properties.

Identify the layers of the dermis

Papillary region is areolar loose connective tissue (closer to the epidermis stratum basale dermal papillae)

Reticular region is dense irregular connective tissue (below papillary)(leather)

thick skin has alot of

demal papillae

is dermis vascular or innervated

is its vascular and has nerves

Identify at least 4 functions of the skin

tough

temp regulation

protect aginst light, water and abrasion

sensory: hair follicles and free nerve endings

making vitamin D

Describe the keratinization process of epidermal growth

Keratinocytes are made by basal cells in the bulb, and as new cells are made, the hair shaft is pushed through the follicle towards the surface

Keratinization is completed as the cells are pushed to the skin surface to form the shaft of our hair

Identify the skin appendages

hair

nails

5 types of glands present in the skin

Sebaceous

Sudoriferous

• Eccrine

• Apocrine

Ceruminous

Sebaceous glands

oil gland

found all over the body and helps to lubricate and waterproof the skin and hair

associated with hair follicles

generate and excrete sebum, a mixture of lipids

secretion of sebum is stimulated by hormones, many of which do not become active until puberty. Thus, sebaceous glands are relatively inactive during childhood

holocrine(sebum and dead cells)

Sudoriferous glands

sweat glands produce sweat to cool the body

develop from epidermal projections into the dermis and are classified as merocrine glands(excreted by exocytosis through a duct without affecting the cells of the gland)

Sudoriferous

• Eccrine

Not associated with hair; everywhere on body for thermoregulation

Produces a hypotonic(water and salts) sweat for thermoregulation help to maintain homeostasis

Abundant on the palms of the hand, the soles of the feet, and the forehead

They are coiled glands lying deep in the dermis, with the duct rising up to a pore on the skin surface, where the sweat is released.

eccrine so: exocytosis release of secretory vesicles

Sudoriferous

• Apocrine

Usually associated with hair follicles in densely hairy* areas, such as

armpits and genital regions.

larger than eccrine sweat glands and lie deeper in the dermis, sometimes even reaching the hypodermis

produce water and salts +includes organic compounds (make the sweat thicker and subject to bacterial decomposition and subsequent smell)

release sweat is under both nervous and hormonal control

apocrine so release of membrane bounded vesical with substance

assoicatied with hair follicle

Ceruminous glands

gland that makes ear max that protects us from bugs

Describe the structure of nails

derived from the epidermis and growth is the same as how skin grows and pushes dead cells up

**used to manipulate, not really for protection

epithelial

nail are derived from the __ tissue and made of __ cells

epidermis

epithelial

Specialized structure of the epidermis that is found at the tips of our fingers

and toes

is rich in blood vessels, making it appear pink

nail bed

what is formed on the nail bed, and protects the tips of our fingers and toes

as they are the farthest extremities and the parts of the body that experience the maximum mechanical stress

and is composed of densely packed dead keratinocytes.

nail body

what has a matrix of proliferating cells from the stratum basale that enables the nail to grow continuously.

nail root

where is nail matrix

closer and deeoer than nail root

The nail fold that meets the proximal end of the nail body forms the

nail cuticle or eponychium

thick layer of epithelium over the nail matrix forms a crescent-shaped region called

lunula

the area beneath the free edge of the nail, furthest from the cuticle, is called

consists of a thickened layer of stratum corneum

hyponychium

Describe the structure of hair

derived from the epidermis and grows like skin; when new cells are made they push old cells up

*made of epithelial tissue

what is something that can stop hair growth

what is something that can cause hair growth

tesoterone

PCOS or meds

if you get a burn all the way to deep dermis will hair grow back

no

hair from from the __ tissue even though it is found in the _

epidermis; the cells in the hair are made of epithelial cells

dermis

epidermal penetration of the demis where hair orginates is the

hair follicle

part of hiar not anchored to the follicle

hair shaft

part of hair that is anchored in the follicle and is below the surface of the skin

hair root

layer of mitotically active basal cells in in the hair bulb

hair matrix

What does the hair bulb surrounding that is made of connective tissue and contain blood capillaries and nerve endings

hair papilla

central core of hair

medulla

layer of compressed keratinzed cells in hair

cortex

outser layer of hiar that is very hard keratinized cells

cuticle

wall of cells that surround the root of growing hair and extends just up to the hair shaft

derived forom basal cells

internal/epithelial root sheath

Wall of cells that is an extension of the epidermis that encloses the hair root

made of basal cells at the bottoms and kerationus cells in the upper regions

external/connective root sheath

wall of cells that are thick and clear connective tissue sheath that covers the hair root and connects it to the dermis

glassy membrane

smooth muscle that contracts in response to nerve signals from the sympathetic nervous system

arrector pili

Outline the process of tissue repair involved in normal healing of superficial

wounds

four functions of bone tissue

Support

Protection: ex pituitary

Movement: attached to skeletal muscle

RBC production in red marrow: RBCs need to be replaced

Fat storage in yellow marrow

****Mineral homeostasis: hormones that regulate calcium storage in bones

Identify the major gross structures of the bone

eipiphysis

metaphysis

diaphysis

medullary cavity

periosteum

endosteum

diaphysis vs epiphysis

diaphysis is the tubular shaft that runs between the proximal and distal ends of the bone.

The wider section at each end of the bone is called the epiphysis

hollow region in the diaphysis is called the __

filled with __ marrow

medullary cavity

yellow

medullary cavity has a delicate membranous lining called the __ where bone growth, repair, and remodeling occur.

endosteum