Chapter 8 - Endocrine System Flashcards
Which system does the endocrine system work with?
Does it work slower or faster than this system?
- The nervous system
- Works slower than the nervous system
What do endocrine glands contain?
Contain secretory cells that release hormones into interstitial fluid where they diffuse into the bloodstream.
What are hormones? - What do they do? - How long do their effects last on the body? - What are their molecular structures like?
Chemical messenger of the body that:
- are released into the bloodstream and act on target cells
- have longer-lasting effects –> can remain in bloodstream for a long period of time
- involved in regulating homeostasis within body (growth, development, metabolism, reproduction)
- larger molecular structure (proteins + steroids)
What are neurotransmitters? - What do they do? - How long do their effects last on the body? - What are their molecular structures like?
Chemical messenger of the body that:
- transmits signals across the synapse to influence neighboring cells (other neurons + muscle cells) –> act faster
- have shorter-lasting effects –> broken down/absorbed faster
- involved in transmitting signals within the nervous system
- smaller molecular structure (amino acids + peptides)
Explain the mechanism of a hormone (4 steps).
- Endocrine glands secrete hormones into the surrounding interstitial fluid.
- In the interstitial fluid, they diffuse directly into the blood.
- Hormones travel through blood vessels to their target cells.
- Hormones bind to their target cells, triggering pathways that lead to changes in the target cell’s behavior.
Explain the mechanism of a lipid-soluble hormone (4 points).
Name 2 examples of lipid-soluble hormones.
List 3 main organs that secrete lipid-soluble hormones.
- Stimulate synthesis of proteins (molecules outside of cell)
- Moves through a cell’s plasma membrane to reach the target cell
- Inside the target cell, it binds with the receptors located in cytoplasm or nucleus (if occurs in cytoplasm, hormone-receptor will move into nucleus of cell)
- In the nucleus, the hormone-receptor attaches to DNA + activates certain genes (synthesis of proteins + enzymes)
- Enzymes alter activity of the cell - Steroids + Hormones derived from cholesterol
- Ovaries + testes + adrenal glands
Explain the mechanism of a water-soluble hormone (4 points).
Name 2 examples of water-soluble hormones.
List 3 main organs that secrete water-soluble hormones.
- Activate cells that already present in the cell
- Cannot enter through the target cell’s lipid bilayer of plasma membrane
- Hormone (first messenger) binds to a receptor on target cell’s plasma membrane
- Conversion of ATP to cAmp –> second messengers (molecules within cell that influence activity of the cell to produce effect of hormone) are activated in cytoplasm
- This conversion activates an enzyme cascade which carries out effect of hormone. - Protein + Peptide Hormone
- Pituitary gland + Thyroid gland + Adrenal gland
Which hormone is an exception to being lipid-soluble/water-soluble?
Thyroid hormone is water-soluble but can also bind to DNA in cell like a lipid-soluble hormone.
Name 5 endocrine glands.
- Pituitary gland
- Thyroid Gland
- Parathyroids
- Adrenal glands
- Pineal glands
Hormone levels in the bloodstream are maintained through which system?
- Negative Feedback System
- Ensures small amount of hormone levels in blood
Explain the Negative Feedback System of hormones:
- where it stimulates lower levels of hormone
- where it stops hormone production (2 ways)
- External conditions –> hypothalamus –> releasing hormone –> anterior pituitary –> tropic hormone –> endocrine gland –> hormone
- External conditions –> hypothalamus –> tropic hormone
External conditions –> hypothalamus –> anterior pituitary –> hormone
Explain the Positive Feedback System of hormones:
- where it further stimulates hormone (ex: oxytocin + uterine contractions during childbirth)
- External conditions (head stretches cervix) –> hypothalamus –> posterior pituitary –> hormone (oxytocin) –> target muscle (uterus contracts) –> ++ contractions stimulates release of oxytocin
- List 3 different types of interactions between hormones.
- Explain their differences.
- Give examples.
- Antagonistic
- Effect of 1 hormone opposes effect of another hormone
-Ex: glucagon increases glucose levels in blood + insulin decreases glucose levels in blood - Synergistic
- Response of a tissue to a combination of hormones is much greater than its response to either individual hormone
-Ex: epinephrine + glucagon prompt the liver to release glucose to blood –> when combined, the amount of glucose is greater than when released by each hormone - Permissive
- 1 hormone must be present for another to exert its effects
- Ex: thyroid hormone must be present for aldosterone to stimulate reabsorption of sodium within kidneys.
Where is the pituitary gland located?
How many lobes does it have? List their names and define them.
- Loacted at base of brain
- 2 lobes: anterior (circulatory connection hypothamalus) + posterior: neural connection to hypothalamus
What is the role of the anterior pituitary?
List 2 hormone examples affecting GH (growth hormone).
- Secretes hormones stimulating hormone secretion
- Secretes inhibiting hormones inhibiting hormone secretion
- Growth hormone-releasing hormone
- Growth hormone inhibiting hormone
- What is the role of the posterior gland?
- List 2 hormones related to this gland and explain their role.
- Name and explain a related health issue to ADH.
- Posterior lobe does not produce any hormones
It stores + releases ADH (antidiuretic) hormone and oxytocin - ADH –> targets kidneys to absorb water
Oxytocin –> stimulates uterine contractions + milk ejection from mammary glands (females) + facilitate sexual behavior + transport sperm (males) - Deficiency in ADH –> diabetes insipidus (excessive urine production + dehydration) can be treated with ADH in nasal spray
- List 3 hormones that the thyroid gland produces.
- Name and explain related health issues to TH.
- Thyroid hormone - produced in follicular cells –> targets thyroid to regulate metabolic waste + production of heat, maintain blood pressure, promote normal functioning of organ systems
Calcitonin - produced by parafollicular cells –> targets bones to absorb calcium + kidneys to release calcium in urine to reduce calcium levels in blood
Parathyroid hormone: targets bones to dissolve bone matrix to release calcium into blood + intestines/kidneys to absorb calcium
- TH:
- Simple goiter –> enlarged thyroid gland (diet deficient in iodine) can be treated by iodine supplements or TH
- Cretinism –> low levels of TH during fetal development/infancy causes dwarfism, delayed mental/sexual development
-Myxedema –> low levels of TH in adulthood causes fluid accumulation in face + decrease in alterness + body temperature + heart rate
- Graves’ disease –> oversecretion of TH where antibodies mimic action of TSH that increases metabolic/heart rate, sweating, nervousness, weight loss, exophthalmos (protruding eyes)
- List 4 hormones the adrenal gland produces.
- What are the roles of the hormones (list their names) secreted by the adrenal medulla?
- Gonadocorticoids (estrogen + progesterone) Gluccorticoids
Epinephrine
Norepinephrine - Epinephrine –> adrenaline
Norepinephrine –> noradrenaline
- Nerve fibers of the sympathetic nervous system stimulate the release of these hormones that deal with short-term stress (fight or flight) by increasing heart rate, blood pressure, blood glucose levels, dilating small passageways of lungs
- Name the endocrine cells in the pancreas
- List 2 hormones produced by the pancreas
- Name and explain a related health issue to these hormones.
- Islets
- Glucagon –> increases glucose + targets liver to convert glycogen into glucose / convert lactic acid + amino acids into glucose
Insulin –> decreases glucose + stimulates transport of glucose into muscle, white blood cells, connective tissue + inhibited breakdown of glycogen to glucose + prevents conversion of amino acids/fatty acids into to glucose - Diabetes mellitus –> high levels of glucose in the blood
