Anatomy and Physiology: EXAM 2

what do cells come from?

pre-existing cells

cytoplasm

fluid between the nucleus and the surface membrane

plasma membrane

A selectively-permeable phospholipid bilayer surrounding the cell

Cytosol

The semifluid portion of the cytoplasm.

aka Intracellular Fluid

Extracellular Fluid (ECF)

fluid outside cells

aka tissue (interstitial) fluid

what percent of the membrane molecules are lipids?

98%

75% of which are phospholipids

Glycocalyx

a bacterial capsule that is made of a fuzzy coat of sticky sugars

acts as an identification tag

transmembrane proteins

Integral proteins spanning the entire membrane.

peripheral proteins

bound to the surface of the membrane

membrane receptors

Transmembrane protein molecules that act enzymatically or as ion channels to participate in signal transduction

only respond to one particular messenger

Ligand-gated ion channels

channels that respond to chemical messengers

Second Messengers

Small, non-protein water soluble molecules or ions that send messages throughout the cells by diffusion.

microvilli

increase surface area

specialized for absorption, like the epithelial cells in the intestines

Cilia

work as the cells antennae

Flagellum

tail of a sperm cell

capillary filtration

passage of fluid across the wall of the capillary; results from the force of blood "pushing" against the walls of the capillaries

water follows?

solute

what solution of NaCl is isotonic to human cells

0.9 (normal saline)

carrier medicated transport

a solute binds to a carrier protein in the plasma membrane, changing the shape and releases the solute to the other side

3 kinds of carriers

uniport, symport, antiport

uniport

carries one type of solute

symports

carry two substances across the membrane in the same direction

aka cotransport

antiports

carry two substances in opposite directions

aka countertransport

3 mechanisms of carrier mediated transport

facilitated diffusion, primary active transport, secondary active transport

facilitated diffusion

carrier-mediated transport of a solute through a membrane down its concentration gradient

requires NO energy

primary active transport

carrier moves a substance through a cell membrane against its concentration gradient

Requires Energy

secondary active transport

Form of active transport which does not use ATP as an energy source; rather, transport is coupled to ion diffusion down a concentration gradient established by primary active transport.

depends on the sodium potassium pump to keep it running

sodium-potassium pump

example of primary active transport

aka NaK ATPase

3 Na+ out, 2 K+ in

4 functions of the sodium-potassium pump

1. secondary active transport

2. regulation of cell volume

3. maintenance of a membrane potential

4. heat production

Endocytosis

vesicular transport into the cell

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

basic components of DNA

sugar, phosphate groups, nitrogenous bases

human cells have how many molecules of DNA?

46

Prymadines

Single ring structure (Cytosine and Thymine)

purines

double-ring structure (Adenine and Guanine)

how are DNA backbones held together?

hydrogen bonds

function of DNA

carries genetic information for synthesis of proteins

where does DNA function

the nucleus

mRNA function

takes genetic code for protein production from DNA to ribosome

Where does RNA function?

cytoplasm

RNA function

protein synthesis

codon

three-nucleotide sequence on messenger RNA that codes for a single amino acid

base triplet of DNA

a sequence of 3 DNA nucleotides that stands for 1 amino acid

Transcription

DNA to mRNA

Translation

mRNA to protein

Anticodon on tRNA

The region of a tRNA that is complementary to a codon on mRNA.

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the cytoplasam

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

cells make more than proteins

they make glycogen, fats, steroids, phospholipids

through enzymatic reactions

DNA helicase

unwinds the double helix (like a zipper)

DNA polymerase

assembles new bases across the existing ones

(like a matchmaker)

mitotic phase

The phase of the cell cycle that includes mitosis and cytokinesis.

creates 2 identical daughter cells

metaphase

Chromosomes line up in the middle of the cell

chromosomes occur in how many pairs?

23

homologous chromosomes

Chromosomes that have the same sequence of genes and the same structure (RR) or (rr)

heterozygous chromosomes

Chromosomes that have a different sequence of genes and a different structure. (Rr)

sex chromosomes

X and Y chromosomes.

autosomes

Any chromosome that is not a sex chromosome

haploid cells

A cell containing only one set of chromosomes (n).

diploid cells

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

germ cells

sex cells

alleles

Different forms of a gene

genotype

genetic makeup

phenotype

physical characteristics of an organism

sex linked traits

Traits controlled by genes located on sex chromosomes.

ex. color blindness

True or False? The hypodermis is part of the skin.

false

What type of tissue is found in the most superficial layer of skin?

stratified squamous epithelium

Which of the following is not a function of the skin?

vitamin C synthesis

Skin covering the ________________ has sweat glands but no hair follicles or sebaceous glands.

fingertips

Which cell is largely responsible for skin color?

melanocyte

Which cell stands guard against toxins, microbes and other pathogens?

dendritic cells

Which layer of the epidermis consists of up to 30 layers of dead cells?

stratum corneum

Female breasts develop mammary glands which are modified _______ sweat glands.

apocrine

What type of sweat glands are a source of sex pheromones?

apocrine

Which cutaneous glands are concerned with cooling the body?

eccrine

True or False? The pain of a third degree burn is greater than that of first and second degree burns.

false

Ear wax, secreted in the external ear, is also called

cerumen

hypodermis

subcutaneous tissue beneath the skin

sebaceous glands

oil glands

ceruminous glands

produce ear wax

only in external ear

skin disorders (ABCD rule)

A- asymmetry

B- border irregularity

C- color

D- diameter (greater than 6mm)

3 main functions of skeleton

protection, movement, blood formation

osseous tissue

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

Hardest substance in the human body

tooth enamel

4 types of bone cells

osteogenic cells, osteoblasts, osteocytes, osteoclasts

osteogenic cells

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

osteoblasts

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

Osteocytes

former osteoblasts that have become trapped in the matrix they deposited

(live inside the lacunae, maintain bone)

osteoclasts

large cells that resorb or break down bone matrix

often have a ruffled border

bone cell development

osteogenic cell -> osteoblast -> osteocyte

bone organic matter is synthesized by

osteoblasts, this includes collagen

bone inorganic matter consists of?

85% hydroxyapatite

what do minerals enable bone to do?

support body weight without sagging

without protein what happens to bone?

becomes brittle with little flexibility

what is the basic structural unit of compact bone?

osteon (haversian system)

what does spongey bone consist of?

trabeculae and spicules

intramembranous ossification

Produces flat bones of skull and clavicle

endochondral ossification

bone forms by replacing hyaline cartilage

epiphyseal plate

Growth plate, made of cartilage, gradually ossifies

how long is an epiphyseal plate present

infancy through adolesense