EXAM #3 Flashcards
Includes all the endocrine glands and
tissues that produce hormones
Endocrine system
Secrete cell product into interstitial fluids around cell or into stream
Endocrine glands
_ are NOT part of the endocrine system
Exocrine glands
secrete cell product onto body surface (internal or external)
- sweat glands
- saliva glands
- digestive tract glands
Exocrine glands
what does the Endocrine system do?
Controls slow, long duration responses
Endocrine system: what does it do?
Regulates _ and _ in body fluids (CA2+)
- fluid balance
- ion concentration
Endocrine system: what does it do?
Regulates absorption of _
nutrients (digestive-insulin)
Endocrine system: what does it do?
Regulates metabolism and _
growth (GH) (Thyroid)
Endocrine system: what does it do?
Regulates sexual characteristics and _
reproduction
Endocrine system: what does it do?
Regulates body’s response to _
stress
- Regulates fluid balance and ion concentration in body fluids
- Regulates absorption of nutrients
- Regulates metabolism and growth
- Regulates sexual characteristics and reproduction
- Regulates body’s response to stress
What the Endocrine system does
Intercellular communication by chemical
messages in 4 ways
- Direct through gap junctions
- Neurotransmitters
- Paracrine factors (local hormones)
- Hormones
Intercellular communication by chemical
messages:
- Released by presynaptic nerve cell
- Produce effects in adjacent postsynaptic cell
- Neurotransmitters
Intercellular communication by chemical
messages:
- Released by most cells into interstitial fluids
- Produce effects in neighboring cells within one tissue
- Paracrine factors (local hormones)
Intercellular communication by chemical
messages:
- Released by endocrine cells into interstitial fluids, diffuse into capillaries
- Produce effects in target cells elsewhere in body
Hormones
Intercellular communication:
Mechanism = _
Transmission = through gap junctions
Chemical mediators = ions, small solutes, lipid-soluble materials
Distribution of effects = Usually limited to adjacent cells of the same type that are interconnected by connexons
Direct communication
Intercellular communication:
Mechanism = Direct communication
Transmission = _
Chemical mediators = ions, small solutes, lipid-soluble materials
Distribution of effects = Usually limited to adjacent cells of the same type that are interconnected by connexons
through gap junctions
Intercellular communication:
Mechanism = Direct communication
Transmission = through gap junctions
Chemical mediators = _
Distribution of effects = Usually limited to adjacent cells of the same type that are interconnected by connexons
ions, small solutes, lipid-soluble materials
Intercellular communication:
Mechanism = Direct communication
Transmission = through gap junctions
Chemical mediators = ions, small solutes, lipid-soluble materials
Distribution of effects = _
Usually limited to adjacent cells of the same type that are interconnected by connexons
Intercellular communication:
Mechanism = _
Transmission = through extracellular fluid
Chemical mediators = Paracrine factors (i.e. histamine)
Distribution of effects = Primarily limited to local area, where concentrations are relatively high. Target cells must have appropriate receptors.
Paracrine communication
Intercellular communication:
Mechanism = Paracrine communication
Transmission = _
Chemical mediators = Paracrine factors (i.e. histamine)
Distribution of effects = Primarily limited to local area, where concentrations are relatively high. Target cells must have appropriate receptors.
through extracellular fluid
Intercellular communication:
Mechanism = Paracrine communication
Transmission = through extracellular fluid
Chemical mediators = _
Distribution of effects = Primarily limited to local area, where concentrations are relatively high. Target cells must have appropriate receptors.
Paracrine factors (i.e. histamine)
Intercellular communication:
Mechanism = Paracrine communication
Transmission = through extracellular fluid
Chemical mediators = Paracrine factors (i.e. histamine)
Distribution of effects = _
Primarily limited to local area, where concentrations are relatively high. Target cells must have appropriate receptors.
Intercellular communication:
Mechanism = _
Transmission = through the circulatory system
Chemical mediators = Hormones
Distribution of effects = Target cells are primarily in other tissues and organs and must have appropriate receptors
Endocrine communication
Intercellular communication:
Mechanism = Endocrine communication
Transmission = _
Chemical mediators = Hormones
Distribution of effects = Target cells are primarily in other tissues and organs and must have appropriate receptors
through the circulatory system
Intercellular communication:
Mechanism = Endocrine communication
Transmission = through the circulatory system
Chemical mediators = _
Distribution of effects = Target cells are primarily in other tissues and organs and must have appropriate receptors
Hormones
Intercellular communication:
Mechanism = Endocrine communication
Transmission = through the circulatory system
Chemical mediators = Hormones
Distribution of effects = _
Target cells are primarily in other tissues and organs and must have appropriate receptors
Intercellular communication:
Mechanism = _
Transmission = across synaptic clefts
Chemical mediators = Neurotransmitters
Distribution of effects = limited to very specific area. Target cells must have appropriate receptors
Synaptic communication
Intercellular communication:
Mechanism = Synaptic communication
Transmission = _
Chemical mediators = Neurotransmitters
Distribution of effects = limited to very specific area. Target cells must have appropriate receptors
across synaptic clefts
Intercellular communication:
Mechanism = Synaptic communication
Transmission = across synaptic clefts
Chemical mediators = _
Distribution of effects = limited to very specific area. Target cells must have appropriate receptors
Neurotransmitters
Intercellular communication:
Mechanism = Synaptic communication
Transmission = across synaptic clefts
Chemical mediators = Neurotransmitters
Distribution of effects = _
limited to very specific area. Target cells must have appropriate receptors
Hormone Communications:
Hormones reach almost all body cells via _
bloodstream
Hormone Communications:
Produce effects only in _ cells that have
_ for the hormone
- “target”
- receptor
Hormone Communications:
Hormone is eventually removed by _
destruction or elimination
Hormone Communications:
Hormone is eventually removed by destruction or elimination
- Freely circulating hormones are _ removed from blood stream
rapidly
Hormone Communications:
Hormone is eventually removed by destruction or elimination
- Hormones bound to _ removed more slowly
transport proteins
Hormone effects on “target” cells
* Target cells have _ for hormone *
receptor
Hormone Communications:
Gene activation leading to synthesis of an
_ or structural _
- enzyme
- protein
Hormone Communications:
- _ of synthesis of an enzyme or structural protein
- Turn an existing enzyme “on” or “off”
Increase or decrease rate
Reflex control of endocrine activity:
_ feedback control mechanism
Negative
Reflex control of endocrine activity:
Negative feedback control mechanism
- in response to changes in composition of
_
interstitial fluids or blood
Reflex control of endocrine activity:
Negative feedback control mechanism
- Location of receptor sensitive to change
may be in the _
gland or in hypothalamus
Reflex control of endocrine activity:
Simple (direct) endocrine reflexes
- _ on gland secreting the hormone
- Example: glucose levels in blood control
insulin release by endocrine cells of
pancreas
Direct effect
Reflex control of endocrine activity:
Complex (indirect) endocrine reflexes
- _ involve hypothalamus, pituitary gland, two or more hormones
Indirect or cascade effects
Hormone communications:
3 Types of hormones
- Amines
- Peptide hormones
- Lipid derivatives
Hormone communications:
Types of hormones
- Norepinephrine, epinephrine, thyroid hormones, etc.
Amines (Amino acid derivatives)
Hormone communications:
Types of hormones
- Insulin, glucagon, growth hormone, etc.
Peptide hormones (chains of amino acids)
Hormone communications:
Types of hormones
- Steroids-structurally related to cholesterol
- Estrogen, testosterone, aldosterone
Lipid derivatives
Amine hormone, Peptide hormone & Protein hormone all have similar _
mechanisms of action
Hormone class _
Components: Amino acids with modified groups
Example: Norepinephrine
Amine hormone
Hormone class _
Components: Short chains of linked amino acids
Example: Oxytocin
Peptide hormone
Hormone class _
Components: long chains of linked amino acids
Example: Human growth hormone
Protein hormone
Hormone class _
Components: Derived from the lipid cholesterol
Example: Testosterone & progesterone
steroid hormones
Mechanisms of hormone action:
Peptide hormones
- Receptors in cell membranes of target cell if
hormone _
cannot cross cell membrane
Mechanisms of hormone action:
Peptide hormones
- Receptors in cell membranes of target cell if
hormone cannot cross cell membrane
- Amines, peptide hormones
- Produce effect via _
G protein-coupled receptors and 2nd messengers
Mechanisms of hormone action:
Peptide hormones
- Produce effect via G protein-coupled receptors and 2nd messengers
- 2nd messenger is _
- Rapidly removed from body
cyclic AMP or calcium
Mechanism of hormone action:
Lipid hormone and Thyroid hormone
- Receptors in the _ for lipid soluble hormones
cytoplasm or nucleus
Mechanism of hormone action:
Lipid hormone and Thyroid hormone
- Thyroid & steroid hormones _ then bind to receptor inside
cross membrane
Mechanism of hormone action:
Lipid hormone and Thyroid hormone
- Produce effect by _ and ATP synthesis
controlling gene expression
Mechanism of hormone action:
Lipid hormone and Thyroid hormone
- Lipid hormones are bound to transport
proteins, so removed from body _
more slowly
Protein hormones (Peptide, Amine):
_, move freely dissolved in plasma
soluble
Protein hormones (Peptide, Amine):
- _ at target cell, binds to G protein-coupled receptor
- activates 2nd messenger
- cAMP
- Ca2+
CANNOT cross cell membrane
Protein hormones (Peptide, Amine):
_ removed from blood stream
rapidly
Lipid hormones & Thyroid (cholesterol, steroid):
- _, must be bound to transport protein in plasma
insoluble
Lipid hormones & Thyroid (cholesterol, steroid):
- _, binds to receptor in cell
CAN cross cell membrane
Lipid hormones & Thyroid (cholesterol, steroid):
Removed _ from bloodstream
slowly
Connected to hypothalamus by
infundibulum
Pituitary Gland (Hypophysis)
Pituitary Gland (Hypophysis):
_ – posterior portion
- developed as outgrowth of CNS
Neurohypophysis
Pituitary Gland (Hypophysis):
_ – anterior portion
- developed as outgrowth of glandular tissue of pharynx
Adenohypophysis
Pituitary Gland (Hypophysis):
Neurohypophysis – posterior portion
- developed as outgrowth of _
CNS
Pituitary Gland (Hypophysis):
Adenohypophysis – anterior portion
- developed as outgrowth of _
glandular tissue of pharynx
Pituitary Gland (Hypophysis):
Releases _ peptide hormones
9
Pituitary Gland (Hypophysis):
Releases 9 peptide hormones
- All 9 bind to membrane receptors and use _ as a second messenger
cAMP or Ca+2
Pituitary Gland (Hypophysis):
_ hormones from Anterior pituitary lobe
7
Pituitary Gland (Hypophysis):
_ hormones from Posterior pituitary lobe
2
Hypothalamus neurons release regulatory
hormones into fenestrated capillaries of
_
hypophyseal portal system
Hypophyseal portal system:
Blood entering the portal system goes to intended _ before returning to general circulation
target cells
Feedback control of hormones of the
adenohypophysis:
Hormone release from adenohypophysis
is controlled by _ secreted by _
- regulatory hormones
- hypothalamus
Thyroid gland produces
C cells (parafollicular cells) and follicle cells
Thyroid gland:
C cells (parafollicular cells)
- Produce _ in response to high calcium ion levels
calcitonin
Thyroid gland:
C cells (parafollicular cells)
_ inhibits osteoclasts and increases Ca2+ excretion by kidney
Calcitonin
Thyroid gland:
Release thyroid hormones
- thyroxine (T4)
- triiodothyronine (T3)
Follicle Cells
Function of thyroid hormones:
Produce strong, immediate, short-lasting
increase in the _
rate of cellular metabolism and use of energy
Function of thyroid hormones:
Cross cell membrane and bind to _ receptors
intracellular
Function of thyroid hormones:
Cross cell membrane and bind to intracellular receptors
- Bind to _ and increase rate of ATP production
mitochondria
Function of thyroid hormones:
Cross cell membrane and bind to intracellular receptors
- Bind to receptors activating genes that
control _ utilization Function of thyroid hormones
energy
Thyroid hormones:
Amino acid with attached _ ions
iodide
Thyroid hormones:
90% of secretions are _ with 4 iodide ions
T4 (thyroxine)
Thyroid hormones:
T4 is converted to _ by enzymes in peripheral tissues
- T3 is the _ of the hormone
- T3 (tri-iodothyronine)
- active form
Thyroid hormones:
Thyroid hormones in bloodstream are attached to transport proteins, creating large reserve supply of _
T4 and T3
Thyroid hormones:
Synthesis and release controlled by _ from
_
- TSH
- adenohypophysis
Function of thyroid hormone:
Essential for normal development of _ during childhood
- Cretinism
skeletal, muscular and nervous systems
Function of thyroid hormone:
Essential for normal _ in adults
- Hypothyroidism
- Hyperthyroidism
- Goiter
metabolic control
Four glands embedded in the posterior
surface of the thyroid gland
Parathyroid glands
Parathyroid glands:
Secretes _ in response to lower than normal
calcium concentration
parathyroid hormone (PTH)
Parathyroid glands:
Secretes parathyroid hormone (PTH) in response to _ than normal _ concentration
- lower
- calcium
Parathyroid glands:
PTH _ concentration
increases
Parathyroid glands:
PTH increases concentration
- Stimulate osteoclasts
- Inhibit osteoblasts
- Decrease Ca2+ excretion by kidneys
- Stimulate formation of _ by
kidneys
calcitriol
Homeostatic regulation of calcium ion
concentration:
_ concentration affects nerve & muscle cell excitability
Ca2+
Homeostatic regulation of calcium ion
concentration:
Ca2+concentration maintained by _ feedback system involving both _ and _
- negative
- PTH & calcitonin
Homeostatic regulation of calcium ion
concentration:
PTH & calcitonin have
effects:
- _ – storage of calcium ions
- Osteoblasts and osteoclasts
Bones
Homeostatic regulation of calcium ion
concentration:
PTH & calcitonin have
effects:
- _ – absorption of calcium
ions
- Calcitriol
Digestive tract
Homeostatic regulation of calcium ion
concentration:
PTH & calcitonin have
effects:
- _ – excretion of calcium ions
Kidneys
Hormones of the adenohypophysis “Tropic Hormones”
- Thyroid stimulating hormone (TSH)
- Adrenocorticotropic hormone (ACTH)
Hormones of the adenohypophysis “Tropic Hormones”:
Thyroid stimulating hormone (TSH) also called _
thyrotropin
Hormones of the adenohypophysis “Tropic Hormones”:
Triggers the release of hormones from thyroid gland
Thyroid stimulating hormone (TSH) (thyrotropin)
Hormones of the adenohypophysis “Tropic Hormones”:
Thyrotropin releasing hormone (TRH) from
hypothalamus promotes the release of _
TSH
Hormones of the adenohypophysis “Tropic Hormones”:
Also called corticotropin
Adrenocorticotropic hormone (ACTH)
Hormones of the adenohypophysis “Tropic Hormones”:
Adrenocorticotropic hormone (ACTH) also called _
corticotropin
Hormones of the adenohypophysis “Tropic Hormones”:
stimulates the release of glucocorticoids from adrenal cortex
Adrenocorticotropic hormone (ACTH) (corticotropin)
Hormones of the adenohypophysis “Tropic Hormones”:
Corticotropin releasing hormone (CRH) from
hypothalamus causes the secretion of _
ACTH
Hormones of the adenohypophysis:
2 Gonadotropins
- Follicle stimulating hormone (FSH)
- Luteinizing hormone (LH)
Hormones of the adenohypophysis:
Gonadotropins
- Stimulates follicle development (egg maturation) & estrogen secretion in ovaries
Follicle stimulating hormone (FSH)
Hormones of the adenohypophysis:
Gonadotropins
- Stimulates sperm production in sustentacular cells of testes
Follicle stimulating hormone (FSH)
Hormones of the adenohypophysis:
Gonadotropins
- Causes ovulation & progestin production in ovaries
Luteinizing hormone (LH)
Hormones of the adenohypophysis:
Gonadotropins
- Causes androgen (testosterone) production in testes
Luteinizing hormone (LH)
Hormones of the adenohypophysis:
Gonadotropin releasing hormone (GmRH) from hypothalamus promotes secretion of _
FSH & LH
Hormones of the adenohypophysis:
- Stimulates the development of mammary glands and milk production
Prolactin (PRL)
Hormones of the adenohypophysis:
Stimulates the development of mammary glands and milk production
- Release stimulated by _ from hypothalamus (inhibited by Inhibiting Hormone)
Prolactin Releasing Hormone
Hormones of the adenohypophysis:
Stimulates melanocytes to produce melanin pigment in skin and other locations
Melanocyte stimulating hormone (MSH)
Hormones of the adenohypophysis:
Stimulates melanocytes to produce melanin pigment in skin and other locations
- In humans, _ MSH is produced by pituitary gland
very little
Growth hormone (GH or somatotropin):
Tropic effect - Cause release of _ from liver
somatomedins
Growth hormone (GH or somatotropin):
Tropic effect - Cause release of somatomedins from liver
- Somatomedins cause increase in amino acid
uptake in skeletal muscle cells, cartilage cells – stimulates _ and cell growth
protein synthesis
Growth hormone (GH or somatotropin):
Direct effect - increase _ in epithelial & connective tissue, enhance break down of lipid & glycogen energy reserves
cell division
Growth hormone (GH or somatotropin):
_ - increase cell division in epithelial & connective tissue, enhance break down of lipid & glycogen energy reserves
Direct effect
Growth hormone (GH or somatotropin):
_ - Cause release of somatomedins from liver
Tropic effect
Growth hormone (GH or somatotropin):
Release controlled by _ and _ from hypothalamus
GH releasing hormone (GH-RH) &
GH inhibiting hormone (GH-IH)
Neurohypophysis (posterior lobe of the pituitary gland):
Contains _ of hypothalamic nerve cells - secrete hormones into blood
axon terminals
Neurohypophysis (posterior lobe of the pituitary gland):
- Decreases the amount of water lost at the
kidneys – decreases urine production
- Elevates blood pressure
Antidiuretic hormone (ADH)
Neurohypophysis (posterior lobe of the pituitary gland):
- Stimulates contractile cells in mammary
glands
- Stimulates smooth muscle cells in uterus
Oxytocin
2 Neurohypophysis (posterior lobe of the pituitary gland) hormones
- Antidiuretic hormone (ADH)
- Oxytocin
Neurohypophysis (posterior lobe of the pituitary gland):
_ hormone —> kidneys
Antidiuretic hormone (ADH)
Neurohypophysis (posterior lobe of the pituitary gland):
_ hormone —> Males: smooth muscle in ductus deferens and prostate gland; Females: uterine smooth muscle and mammary glands
Oxytocin (OXT)
secretes epinephrine and norepinephrine
Adrenal medulla (neuro-endocrine cells)
secretes steroid hormones (corticosteroids)
Adrenal cortex (gland cells)
Adrenal medulla (neuroendocrine cells):
Secretes _ (~75 - 80%)
epinephrine
Adrenal medulla (neuroendocrine cells):
Secretes _ (~20-25%)
norepinephrine
Adrenal medulla (neuroendocrine cells):
Secretes epinephrine & norepinephrine
- Produce increased availability of _
energy resources
Adrenal medulla (neuroendocrine cells):
Produce increased availability of energy resources
- Cause breakdown of glycogen in liver to release glucose for use by _
brain
Adrenal medulla (neuroendocrine cells):
Produce increased availability of energy resources
- Cause breakdown of _ for use by other cells of body
fat to release fatty acids
Adrenal medulla (neuroendocrine cells):
Produce increased rate & force of _ contractions and other _ effects
- cardiac
- sympathetic
Adrenal medulla (neuroendocrine cells) controlled by _ activity
Autonomic Nervous System
Adrenal cortex (secretes corticosteroids):
3 types
- Mineralocorticoids (aldosterone)
- Glucocorticoids
- Androgens
Adrenal cortex (secretes corticosteroids):
- Secreted if Na+ is low, K+ is high, or BP is low
Mineralocorticoids (aldosterone)
Adrenal cortex (secretes corticosteroids):
- Cause retention of Na+ and water, loss of K+
Mineralocorticoids (aldosterone)
Adrenal cortex (secretes corticosteroids):
Mineralocorticoids (aldosterone)
- Cause retention of _, loss of K+
Na+ and water
Adrenal cortex (secretes corticosteroids):
Secreted in response to ACTH release from anterior pituitary
Glucocorticoids
Adrenal cortex (secretes corticosteroids):
Glucocorticoids
- Cause decrease _ and increased rate of glycogen synthesis
- Have anti-inflammatory effects
use of glucose
Adrenal cortex (secretes corticosteroids):
- encourages bone and muscle growth, blood formation
- testosterone
Androgens
Adrenal cortex (secretes corticosteroids):
Androgens
- primary role is in _; testes of adult males produces larger amounts
children & women
Pineal gland secretes _
melatonin
Pineal gland:
Melatonin
- Increased _ exposure causes _ melatonin secretion
- sunlight
- decreased
Pineal gland:
Possible functions include:
– setting circadian rhythms
– anti-oxidant
– inhibiting reproductive function
Melatonin
Pineal gland:
Depression correlated with decreased sunlight exposure and increased melatonin
Seasonal Affective Disorder
99% of pancreas is _ cells
– secrete enzymes into digestive tract
exocrine
Pancreas:
Endocrine cells occur in _
small clusters
Pancreas:
Endocrine cells occur in small clusters
- Islets of Langerhans or pancreatic islets
“islands” on pancreas that are only providing hormones
Pancreas:
Endocrine cells occur in small clusters
- Secrete hormones involved in regulation of
_ level
blood glucose
Pancreas:
Alpha cells secrete _ in response to _
blood glucose levels
- low
- glucagon
Pancreas:
_ cells secrete glucagon in response to low
blood glucose levels
Alpha
Pancreas:
Beta cells secrete _ in response to _ blood glucose levels
- insulin
- high
Pancreas:
_ secrete insulin in response to high blood glucose levels
Beta cells
_ secreted by Beta (β) cells
Insulin
Insulin – secreted by Beta (β) cells:
_ blood glucose levels
lowers
Insulin – secreted by Beta (β) cells:
Increases rate of glucose uptake & utilization
in _ cells
insulin-dependent
Insulin – secreted by Beta (β) cells:
Increases rate of glucose uptake & utilization
in insulin-dependent cells
- Glucose used for energy production and/or
synthesis of glycogen and other energy storage _
macromolecules
Insulin – secreted by Beta (β) cells:
Increased uptake of _ & synthesis of _ in adipose cells
- fatty acids
- triglycerides
Insulin – secreted by Beta (β) cells:
Increased uptake of _ & synthesis of proteins
amino acids
_ secreted by Alpha (α) cells
Glucagon
Glucagon – secreted by Alpha (α) cells:
_ blood glucose levels
raises
Glucagon – secreted by Alpha (α) cells:
Increases the rate of _
glycogen breakdown
