chpt 10.1&10.2 test Flashcards
JAN 10
Hormones act as chemical messengers which enable
one part of the body to give instructions to another part
Local regulators act on – and may even self regulate, producing chemicals to –.
nearby cells rather than cells some distance away, stimulate their own cellular processes.
Hormones are secreted by the …
cells, tissues, and organs that compose the endocrine system
The endocrine system regulates and coordinates – and contributes to the control of –
- the functions of organs throughout the body
- growth, development, reproduction, behaviour, energy metabolism, and water balance
The nervous and endocrine systems are — related, but they control — in different ways.
- structurally, chemically, and functionally
- organ and tissue functions
The nervous system sends – and the speed of these nerve impulses enables an organism to interact rapidly with its external environment.
fast electrical signals along the nerves
The endocrine system uses hormones, with — so that hormones are released when needed.
slower/ longer-acting responses (to control organ and tissue functions and itself has to be controlled)
The nervous system can regulate –, it ultimately controls the –.
the release of most hormones, actions of the endocrine system
Endocrine glands are…
ductless secretory organs that secrete their hormones directly into the blood or extracellular fluid
Exocrine glands (such as the sweat and salivary glands) release their secretions into …
ducts that lead outside the body or into the body cavities
Hormones are then —. Most body cells are constantly exposed to a wide variety of hormones.
circulated throughout the body in the blood and other body fluids
Target cells will respond to a specific hormone because …
only they have receptor proteins that recognize and bind to that type of hormone.
Hormones are cleared from the body at a — by —…
- steady rate
- enzymatic breakdown in target cells/blood, or/organs and the breakdown products are reused or excreted.
There are more than — known hormones and local regulators in humans. Hormones are identified by their —.
60, chemical structure
Protein hormone is a hormone composed of —. It usually acts on —.
- chains of amino acids (3-200+) that is water soluble
- cell membrane receptors
protein hormone: produced in —, released into —, usually hydro— and —- through the blood and intercellular fluids.
— regulate the division and differentiation of many types of cells in the body
endocrine glands, blood/extracellular fluid, -philic, diffuse well, Growth factors
Steroid hormone is a hormone composed of — that is —. It usually passes through —.
cholesterol, not very water soluble, the cell membrane and acts on receptors inside the cell
steroid hormone:
-pass/diffuse —
-combine with hydrophilic carrier proteins to form —
- include aldosterone, cortisol, and the sex hormones.
Some similar structures but — (testosterone and estradiol). differ only in —
easily, water-soluble complexes, very different effects, the presence or absence of a single methyl group.
Many hormones are secreted in an inactive or less active form called — which are converted by the —
prohormones, target cells or by enzymes in the blood or other tissues to the active form.
— are commonly synthesized as pro-hormones and then are converted to the active form in the source cell.
Protein hormones
Blood Pressure Hormone:
Angiotensin
secreted by the — as angiotensinogen —> an — cleaves an inactive form of angiotensin from angiotensinogen —> inactive form is converted to the active hormone by the angiotensin-converting enzyme (ACE) —> results in —
liver, enzyme, an increase in blood pressure.
— are often prescribed to control high blood pressure
ACE inhibitor
Hormones are usually secreted in —, but a process of — magnifies their effects.
relatively small amounts, amplification (Once a receptor cell activates a few proteins, these proteins activate other proteins, each of which activates other proteins, and so on. )
The secretion of most hormones is regulated by —
negative feedback mechanisms
Negative Feedback Mechanism = a chemical that is affected at the end of the action pathway of a hormone controls the further action of the hormone by —
inhibiting an earlier chemical reaction.
A response in a feedback loop may be — of a substance or a — of a substance.
the production, decrease in the production
Hypothalamus releases —(TRH), which initiates a —. As the concentration of the thyroid hormone in the blood increases, it inhibits an earlier step in the pathway, the secretion of — (TSH) by the pituitary gland.
thyroid-releasing hormone , pair of hormone releases by the pituitary and thyroid glands, thyroid-stimulating hormone
Some glands —, and many body processes are affected by —.
produce multiple hormones, more than one hormone at a time
Blood concentrations of — are regulated by the coordinated activities of several hormones, which are secreted by different glands.
glucose, fatty acids, and calcium, potassium and sodium ions
In many systems, negative feedback loops adjust the — in their effects that maintains homeostasis in the body. Five separate hormone systems such as the — all act together in a coordinated fashion to keep the body’s fuel levels in balance between meals.
- level of secretion of hormones that act in opposing ways and creates a balance,
- digestive tract, pancreas, nervous system, and pituitary and adrenal glands,
Protein hormones bind to receptor molecules in the cell membrane, causing …
the receptor molecule to change shape.
Mechanism: a. Hormone binds to —.
b. Activated receptor triggers a —
c. Signal leads to —.
- surface receptor and activates it
- signal pathway (signal passes into the cell and causes further changes, ex. release of enzymes that add phosphate groups, activating/ deactivating them)
- cellular response (may act in the cytosol only, or it may affect the nucleus of the cell)
Protein hormone: Glucagon (pathway)
glucagon binds to surface receptors on liver cells —> triggers a series of reactions
—> lead to the addition of phosphate groups —> activate the enzyme —> breakdown of stored glycogen into glucose
Glucagon is a hormone produced by — that r— by promoting the breakdown of glycogen in the liver.
alpha cells in the pancreas, raises the blood glucose level