Chapter 30: Animal Hormones Flashcards
Target cell
the cell that signals travel to
have receptor proteins that recognize and bind to a signal even at low concentrations
Endocrine system
cells that produce and release hormones
Endocrine secretion
the secretion of substances into the extracellular fluid
Exocrine secretion
Secretion of substances into the outside world OR an internal body cavity
Is sweating endocrine or exocrine secretion?
exocrine secretion
Is the release of enzymes into the digestive tract endocrine or exocrine secretion?
exocrine secretion
Endocrine cells
cells that secrete endocrine signals
some are in larger organs on their lonesome [like in the digestive tract]
other hand out together to form organs
Endocrine glands
Secretory organs
Like the thyroid
Hormones
Long distance endocrine signals
Peptide and Protein hormones
relatively large
water soluble
easily transported in the blood
packaged in vesicles and released by exocytosis
Receptors for them MUST be on the exterior of the cell [because of polarity]
Biggest group of hormones
Steroid Hormones
Made from cholesterol Four interlinked rings Lipid-soluble Pass through the membrane of cells Don't dissolve well in blood, so they generally are carried by (guess what?) carrier proteins
Amine Hormones
Small molecules
from single amino acids
Polarity of amino acid determines whether or not the amino acid is soluble
Do sponges have nervous systems?
no, but they have intercellular communication
What controls molting??
Hormones [JH]
Instars
the growth stages between molts
What triggers a molt?
A blood meal
True or falseL Rhodinus survive for more than a week without its head
true `
True or false Rhodinus molts if decapitated an hour after its blood meal
false, one week
PTTH
protothoraciotropic hormone
controls molting in arthropods
produced by the brain
JH
juvenile hormone
determines the outcome of molting
in high concentrations, the bug becomes large juvenile after a molt
in low concentrations, the bug becomes an adult
complete metamorphosis
Dramatic Developmental change
Larva
what a fertilized egg hatches into
Pupation
the stage the larva enters after some number of molts
Pupa
major body reorganization
emerges as adult
What happens if a cell does not have a receptor for a particular protein?
It will not be affected by it
binding domain
part of peptide receptor
projects outside the plasma membrane
transmembrane domain
anchors receptor in protein
Cytoplasmic domain
initiates target cell response
fight-or-flight response
controlled by amine protein epinephrine
physiological response to stressful situations
adrenal glands
right above your kidneys
secrete epinephrine and norephinephrine
Adrenergic receptors
five different types G-protein linked receptors Two basic categories a-adrenergic and b-adrenergic
b-adrenergic receptor
cause a faster and stronger heartbeat
skeletal muscles dilate for RUNNING
fat breakdown in liver energy
a-adrenergic receptors
cause blood vessels in the skin to constrict
causes pallor and cold hands and feet
shut down receptors in digestive system and decrease blood flow there
downregulation
Continuous high concentration of a hormone decreases the number of receptors in the target cell’s cytoplasm
makes cells less sensitive
Ex. Type two diabetes
Upregulation
hormone is chronically low
make more receptors
ex. regular dose of beta blockers and go off medication, increase anxiety and bp
Neurohormones
hormones secreted by neurons
Pituitary
endocrine gland that serves as an intermediary between the nervous and endocrine systems
involved in the hormonal control of many physiological processes
anterior pituitary
releases four tropic hormones
makes and secretes its own hormones
but under control of hypothalamus
posterior pituitary
neurohormones released like ADH and oxytocin
tropic hormones
in control of endocrine glands
GH
acts on a wide variety of tissues to promote growth
portal blood vessels
begin in capillaries
