BIO220H1 Chapter 5: Chapter 5 chapter notes

68 views2 pages

skymammoth432

25 May 2011

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

qq919649100 and 40133 others unlocked

BIO220H1 Full Course Notes

Verified Note

38 documents

Document Summary

Chapter 5: chemical messengers (selected based on lecture) Classes of chemical messengers: paracrines chemicals that communicate with neighboring cells. E. g. histamine responsible for allergic rxns and inflammations. secreted to ecf and reach target cell by diffusion. includes growth factors proteins that stimulate proliferation and differentiation of. cytokines cells function like paracrines and hormones travel thru bloodstream. Peptides release from immune system functioning as body defense and: neurotransmitters. Post synaptic target cell: hormones chemicals release from endocrine glands into if whre they can diffuse to blood to target cells. Neurohormones release by special class of neurons called neurosecretory cells though similar mechanism to nt release. Adh or vasopressin which is synthesized by neurosecretory cells originating in hypothalamus. Adh located in posterior pituitary glands travels in blood to its target. Lipophilic hydrophobic lipid soluble and ready to cross plasma membrane e. g. steroids, Eicosanoids paracrines that is lipids and insoluble to water.

Related Questions

Match the statements below with the correct mode of cellsignaling by placing the letter in the blank.

A. Paracrine

B. Endocrine

C. Autocrine

__ The adrenal gland releasesadrenaline into the bloodstream to act on muscle cells

__ A neuron releasesneurotransmitters into the synapse to bind to another neuron

__ B cells of the immune systemrelease cytokines that bind to their own receptors to stimulatecell proliferation

__ The pancreas releases insulin intothe bloodstream to act on liver cells

crimsoncockroach373

Glucose can be released from the liver and transported to many other tissues where it is taken up and induces a variety of biological effects. Glucose concentrations in animals range between 40 and 150 mg/100 mL. Based on this information, would you consider glucose to be a hormone? Why or why not? One important characteristic that distinguishes hormones from other chemical messengers is that hormones circulate in extracellular fluids in very low concentrations; that is, at concentrations ranging from picograms (1012 g) to nanograms (109 g) per mL of blood. This is much lower than concentrations of vitamins, minerals, and metabolites, which are present in concentrations of micrograms (106 g) and milligrams (103 g) per mL of blood. based on this is glucose a hormone

GnRH, a peptide hormone produced by hypothalamic neurosecretory cells, and a steroid hormone produced by the ovary, each exert effects on LH-producing cells of the anterior pituitary gland. In general terms, compare and contrast how these hormones act to affect LH release by pituitary cells.

thank you

From the following list, select all options that are correctwith respect to the synapse.

Question 5 options:

A)	the synapse is the site where the plasma membrane that coversthe axon terminal of one neuron makes direct contact with and fusesto the plasma membrane on the cell body or dendrite of anotherneuron

B)	the action potential travels through extracellular fluid in thesynapse to get from one neuron to the next

C)	presynaptic nerve terminals release chemical messengers into thesynapse in response to arrival of an action potential

D)	signaling molecules in the synapse can be broken down by enzymesthat are present on the post synaptic cell membrane

E)	signaling molecules in the synapse can bind to 're-uptake'receptors and be taken back into the presynaptic neuron forbreakdown or for repackaging/reuse

F)	signaling molecules can be taken into and degraded within thepostsynaptic cell

G)	signaling molecules in the synapse function as chemicalmessengers that regulate the opening of ligand-gated channels inthe plasma membranes of post synaptic cells