Chapter 16 P1 Flashcards
What system does the endocrine system work with?
The nervous system
What do the endocrine and nervous do for homeostasis?
Integrate and Coordinate activity of body cells
What does the endocrine system influence and how does it influence it?
Metabolic activities
Influenced by hormones transported in blood
What kind of response do hormones create compared to nerve impulses?
Slower but longer lasting
What is endocrinology?
Study of hormones and endocrine organs
What does the endocrine system control and integrate?
Reproduction
Growth
Development
Maintenance of Electrolyte, water and nutrient balance of blood
Regulation of cellular metabolism and energy balance
Mobilization of body defenses
What are the two types of glands
Exocrine
Endocrine
What kind of glads produce hormones and lack ducts?
Endocrine glands
What do exocrine glads use to secrete substances and what are those substances?
Ducts that secrete sweat and saliva (nonhormonal)
What glands are in the Endocrine System?
Pituitary Thyroid Parathyroid Adrenal Pineal Glands
What kind of organ is the hypothalamus?
Neuroendocrine organ
What glands are both endocrine and exocrine?
Pancreas and Gonads
What are the 3 types of chemical messengers?
Hormones
Autocrines
Paracrines
What type of chemical messengers act locally and are quicker?
Autocrines
Paracrines
By what substance are hormones transported?
Blood
Lymph
What do autocrines exert their secretion to?
The same cell that produce them
What are the two classes of hormones?
Amino Acids
Steroids
What are the types of amino acid based hormones?
Peptides
Proteins
Amino Acids
What are steroids synthesized from?
Cholesterol
What hormones are steroids?
Gonadal
Adrenocortical hormones
What cells are affected by hormones?
Target cells
Tissues with receptors for specific hormones
In what way do hormones alter target cell activities?
Plasma membrane permeability Membrane permeability Stimulate synthesis of enzymes Activate or deactivate enzymes Induce secretory activity Stimulate mitosis
What 2 ways do hormones act at receptors?
By their chemical nature
By their receptor location
What are the two types of soluble hormones?
Water soluble
Lipid soluble
What hormones are water soluble hormones?
All except thyroid hormones
Can water soluble hormones enter the cell?
No they must bind to receptors on the membrane
How do water soluble hormones act on the cell?
Plasma membrane via G proteins and Second messengers
What are the types of secondary messengers?
cAMP
cGMP
PIP2-Calcium
What do lipid soluble hormones do for the cell?
They enter the cell and directly activate genes
How do lipid soluble membranes travel to the cell?
Transport proteins
What are two types of lipid soluble hormones?
Steroids
Thyroid hormones
TF: Hormones have specificity
True
What must target cells have to be affected by hormones?
Specific receptors to which hormones bind
What type of receptors are found on nearly all cells of body?
Thyroxine receptors
What does target cell activation depend on?
Blood levels of hormone
Repetitive number of receptors on or in the target cell
Affinity of binding between receptor hormone
What are the two types of regulation that hormones use to influence receptors?
Upregulation
Downregulation
What is upregulation?
Target cells form more receptors to low levels of hormones
What is down regulation?
Target cells lose receptors to too high levels of hormone1
What system do hormones use to regulate blood levels of hormones?
Negative feedback
What regulates the release and synthesis of hormones from endocrine glands?
Humoral stimuli
Neural stimuli
Hormonal stimuli
How does humoral stimuli influence release and synthesis of hormones?
Change in ions and nutrient levels in blood stimulates secretion of hormones
(Calcium levels low causes increase in PTH that causes osteoclast activity to increase to increase blood calcium)
How does neuronal stimuli influence release and synthesis of hormones?
Nerve fibers stimulate hormone release
sympathetic nervous system fibers stimulate adrenal medulla to secrete catecholamines
How does hormonal stimuli influence hormone synthesis and release?
Hormones stimulate other endocrine organs to release their hormones
(hypothalamic hormones stimulate release of anterior pituitary hormones which causes secretion of more hormones)
What system can override normal endocrine controls?
Nervous system
stress
How do hormones circulate in the blood?
Free
Bound
What are steroids and thyroid hormones attached to for blood transport?
Plasma proteins
What does the concentration of circulating hormones reflect?
Rate of release
Speed of inactivation and removal from body
How are hormones removed from blood?
By degrading enzymes
Kidneys
Liver
What is half life?
Time required for hormone’s blood level to decrease by half
What is the range of half life?
One fraction of a minute to a week
How long do steroids usually take for the onset of action to occur?
Hours to days
What kind of duration of action do hormones have?
Limited duration of action (10 seconds to hours)
When do effects of hormones disappear?
When blood levels drop
TF: Hormones can persist at low blood levels?
True
TF: Only one hormone can act on a target cell at a time?
False
Multiple hormones may act on same target at the same time
What is the idea of permissiveness?
One hormone cannot exert its effects without another hormone being present
What hormone exhibits permissiveness?
Thyroid hormone
What is the idea of synergism?
More than one hormone produces the same effects on target cell (amplifies effect)
What hormones exhibit synergism?
Glucagon and epinephrine
work together to stimulate glucose release from the liver and into the blood
What is the idea of antagonism?
One or more hormones oppose action of another hormone
What hormones exhibit antagonism?
Glucagon raises blood glucose
Insulin reduces blood glucose
What are the two lobes of the pituitary gland?
Posterior pituitary Anterior pituitary (adenohypophysis)
What kind of tissue is the posterior pituitary?
Neural tissue
What kind of tissue is the anterior pituitary?
Glandular tissue
What is the hypothalamic-hypophyseal tract?
A neural connection to the hypothalamus from the posterior pituitary glad
What NEUROhormones does the nuclei of the hypothalamus synthesize?
Oxytocin Antidiuretic Hormone (ADH)
How do oxytocin and ADH differ?
By two amino acids
Where do oxytocin and ADH go after leaving the hypothalamus?
To the posterior pituitary where they are stored
What does oxytocin do?
Stimulates uterine contraction
Triggers milk ejection
Acts as neurotransmitter in the brain
When is oxytocin released?
During childbirth
What does ADH do?
Inhibits or prevents urine formation
Regulates water balance
What is another name for ADH?
Vasopressin
Where does ADH target?
Kidneys tubules - reabsorb more water
What is ADH release triggered by?
Pain
Low blood pressure
Drugs
What is ADH inhibited by?
Alcohol
when you drink you pee alot more
What does high concentration of ADH cause?
Vasoconstriction (remember it causes an increase of blood pressure through vasoconstriction)
What causes Diabetes INSIPIDUS?
ADH deficiency due to hypothalamus or posterior pituitary damage
(THIS IS definitely ON TEST)
What happens when a person has diabetes insipidus (Definitely on test)?
Elimination of too much water (dehydration)
What is SIADH?
Syndrome of inappropriate ADH secretion
What happens in a person who has SIADH?
Retention of fluid, headache, disorientation
fluid restriction - blood sodium level monitoring
What pressure is increased due to SIADH?
Inter cranial pressure
What is the hypophyseal portal system?
Vascular connection to hypothalamus from the anterior pituitary
(portal system)
What does the hypophyseal portal system do?
Carries releasing and inhibiting hormones to anterior pituitary to regulate hormone secretion
In what two ways is secretion of anterior pituitary hormones regulated?
5 releasing and 2 inhibiting hormones in the hypothalamus stimulate or inhibit their secretion
Negative feedback via hormones released by target glands decreases secretion of three types of hormones
What are the 6 Anterior pituitary hormones?
Growth hormone Thyroid stimulating hormone (thyrotropin) Adrenocorticotropic hormone Follicle stimulating hormone Luteinizing hormone Prolactin
What hormones of the anterior pituitary activate cyclic AMP second messenger systems at their target cells?
All except Growth hormone
What kind of hormones are TSH, ACTH, FSH, and LH
Tropic hormones
What are tropic hormones?
Hormones that regulate secretory action of other endocrine glands
What is another name for hGH?
Somatotropin
What does hGH do?
Stimulates secretion of insulin like growth factors that promote growth
What does TSH do?
Stimulate synthesis and secretion of thyroid hormones by the thyroid glands
What does PRL do?
Stimulates breast growth and development of the mammary glands
What hormones from the hypothalamus secrete that cause secretion of FSH and LH?
Gonadotropic releasing hormones
What does FSH do?
Ovaries initiate development of oocytes
Testes initiate development of spermatozoa
What does LH do?
Ovaries stimulate ovulation
Testes stimulate testosterone production
What two hormones are released in response to the hypothalamus releasing corticotropin releasing hormone?
ACTH and MSH(melanocyte stimulating hormone)
What does ACTH do?
Stimulate release of mineralocorticoid, glucocorticoid, and androgen hormones from the adrenal cortex
What does MSH do?
Stimulate the production of release of melanin by melanocytes in the skin and hair
In brain-sex and appetite
