chemical signaling

nervous system

brain, spinal cord, nerves

endocrine system

endocrine organs

nervous system distance from starget cells

near, almost touches it

synaptic cleft

a microscopic gap that separates the axon terminal of a sending neuron from a receiving

disntance from target cells for endocrine cells

far away

type of signal for nervous system

electrical (nerve impulse)

type of signal for endocrine system

chemical (hormone)

speed of signal for nervous system

travels fast

speed of signal for endocrine system

travels slowly

specificity of signal for nervous system

very specific

specificity of signal for endocrine system

not very specific

what do both nervous system and endocrine system act as

transducers

transducers

things that can take one form of energy or information and convert it into another form of energy or information

neural secretory cell

secrete neuro hormones

autocrine signaling (autocrines)

secretes back onto itself

short distance

paracrine signaling (paracrines)

secretes chemicals into body, never makes it to the blood

long distance

endocrine signaling (hormones and neurohormones)

into the extracellular fluid and bloodstream to regulate distant target cells

pheromonal signaling (pheromones) examples

prison effect, dorms

how do menstral cycles sync

from pharamones

oxytocin

brain chemical released.

Hormone is about affiliation not sex, feeling safe and familiar with someones

first messenger

extracellular

hormone, neurotransmitter, or paracrine or cytokine

most are polar, water soluble and can’t come in

second messenger

intracellular

brought into cell from outside SOMETIMES or mostly created on inside

keeps message going when 1st messenger can’t get in

nerotransmitters

first messenger

short distance (autocrines)

hormones

first messenger

long distance (paracrines)

cytokines

first messenger

comes out of traveling cells

immune system

calcium and cAMP examples of what type of messenger

second messenger

signal amplification

number of molecules keeps increasing because each enzyme can run multiple times

signal amplification by adenylate cyclase

first messenger activates receptor

cAMP activates protein kinase

each enzyme can be reused, causes a lot more made each step

G proteins

positive and negative G proteins

what does phospholipase c do

cuts lipids to create IP3 and DAG, 2 separate second messengers

slide 8 need to understand

go back to notes ask scarlett

is protein kinases second messenger

no, it gets activated by them

is NO and CO used as first messengers or second messenger

second messengers

NO pathway

L-arginine activates nirtic oxide synthase which goes to NO which activates guarylyl synthase. GTP finishes it

JAK (janus kinase)

intracellular, non-receptor tyrosine kinases that transmit chemical signals from outside the cell membrane to the nucleus via the JAK-STAT signaling pathway

Signal Transduction Using Inherent Tyr-K. where is tyrosine kinase

inside the receptor

phospholipase A

Cuts phospholipid and creates Arachidoric acid

lipid soluble messenger (steroids hormones and thyroid hormones)

can dissolve through membrane and enter the cell

does not need second messenger

Eicosanoid

shared by nervous and endocrine system

signals with many actions

what is Arachidonic acid effected by

cyclooxylgenase or lipoxygenase which are second messenger

A signal's specific message is determined by

The original chemical signal (= first messenger).

The specific chemical receptor for the signal.

The mechanism of signal transduction used by the receptor.

The enzymes/chemicals in the target cell that can respond to the signal transduction system

Signal transduction

the carrying of an extracellular signal across a membrane into a cell. This may

require creating a new chemical (second messenger) within the target cell.