Lecture 3 Flashcards
Hormones travel around the body through ____ and can travel up to __m
the bloodstream; 2m
What metaphors were presented to distinguish between neural and hormonal communication?
- neural: train on tracks (fast but only one path)
- hormonal: bikes (go anywhere but slowly)
What is intracrine communication/mediation?
- intracrine substances regulate intracellular events
What is autocrine communication/mediation?
- autocrine substances feed back to influence same cells that secreted them (ex steroid hormones have receptors for their own secreted products)
What is paracrine communication/mediation? What is one example?
- paracrine cells secrete chemicals that affect adjacent cells
- ex neurons!
What is endocrine communication/mediation?
- secrete chemicals into bloodstream where they may travel to distant targets
- main comm. mode of hormones!
What is ectocrine communication/mediation?
- ectocrine substances (eg pheromones) are released into environment to communicate w others
Match the term to the definition:
Any substance produced by a cell that affects function of another cell
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
chemical messenger
Match the term to the definition:
A peptide hormone produced by a neuron
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
neuropeptide
Match the term to the definition:
A chemical messenger that acts across the neural synapse
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
neurotransmitter
Match the term to the definition:
A chemical messenger that is released into blood and affects function of target cells some distance from source
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
hormone
Match the term to the definition:
A hormone produced by a neuron
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
neurohormone
Match the term to the definition:
A hormone that changes the response of a neuron to some other factors (eg testosterone)
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
neuromodulator
Match the term to the definition:
A chemical messenger that evokes proliferation of other cells, esp. in immune system
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
cytokine
Match the term to the definition:
A steroid hormone produced by a neuron
Chemical messenger, Cytokine, Hormone, Neurohormone, Neuromodulator, Neuropeptide, Neurosteroid, Neurostransmitter
neurosteroid
(T/F) Endocrine glands can communicate through ducts
FALSE
ductless so rely on blood vessels and exocrine glands for communication!
(T/F) endocrine glands have a rich blood supply
TRUE
(T/F) glands can be both endocrine and exocrine
TRUE (ex pancreas)
(T/F) hormone receptors can be located within the cell
TRUE (embedded in membrane or within cell)
What is “resistance” in relation to hormones?
- insufficient receptors can cause endocrine deficiency
- ex insulin resistance in T2 diabetes
What is “cross-reaction”?
when blood conc of hormone is high, binding w receptors specific for another related hormone can occur
Peptide hormones :
- are (water/lipid) soluble
- (can/t) pass through cell membrane without binding to surface receptor
- (need/don’t need) carrier proteins to be transported in blood
- are water soluble
- CAN’T pass thru membrane (use exocytosis)
- don’t need carrier proteins to travel in blood
Steroid hormones :
- are (water/lipid) soluble
- (can/t) pass through cell membrane without binding to surface receptor
- (need/don’t need) carrier proteins to be transported in blood
- are lipid soluble
- CAN pass thru membrane (via diffusion)
- NEED carrier proteins to travel in blood
Catecholamines (tyrosine derivative) are very similar to _______
peptide hormones
Thyroid hormones (tyrosine derivative) are very similar to _____
steroid hormones
2 main examples of peptide hormones
insulin, parathyroid hormone
3 main examples of steroid hormones
estrogen, androgens, cortisol
2 main examples of catecholamines
epinephrine, norepinephrine
1 example of thyroid hormones
thyroxine (T4)
What is the main function regulated by secretion of the hypothalamus?
- control of hormone secretions
What is the main function regulated by secretion of the pineal gland?
- reproductive maturation, body rhythms
What is the main function regulated by secretion of the anterior and posterior pituitary?
- ant: hormone secretion by thyroid, adrenal cortex, gonads; growth
- post: water and salt balance
What is the main function regulated by secretion of the thyroid?
- growth and development, metabolic rate
What is the main function regulated by secretion of the adrenal glands (cortex and medulla)?
- cortex: salt/carb metabolism, inflammatory rxns
- medulla: emotional arousal
What is the main function regulated by secretion of the pancreas (islets of Langerhans)?
- sugar metabolism
What is the main function regulated by secretion of the gut?
- digestion and appetite control
What is the main function regulated by secretion of the gonads?
- body dev, maintenance of reproductive organs (adults)
What is the main function regulated by secretion of the placenta?
- auxiliary organ to produce hormones necessary for embryonic development
What are the main releasing hormones of the hypothalamus? (6)
- thyrotropin-releasing hormone (TRH)
- growth hormone releasing hormone (GHRH)
- gonadotropin releasing hormone (GnRH)
- melanotropin releasing hormone (MRH)
- corticotropin releasing hormone (CRH)
- kisspeptin
What are the main inhibiting hormones of the hypothalamus? (3)
- somatostatin (GH inhibiting hormone; GHIH)
- gonadotropin inhibitory hormone (GnIH)
- dopamine (DA)
Corticotropin releasing hormone (CRH) is synthesized within the _____ and stimulates the secretion of ______
hypothalamus; adrenocorticotropic hormoen
Gonadotropin releasing hormone (GnRH) is synthesized within the _____ and controls release of ____ and ___
hypothalamus; luteinising hormone (LH) and follicle stimulating hormone (FSH)
Growth hormone releasing hormone (GHRH) is synthesized within the ____ and stimulates secretion of ____
hypothalamus; growth hormone
Thyrotropin releasing hormone (TRH) is synthesized within the ___ and stimulates cells in anterior pituitary to release____
hypothalamus; thyroid-stimulating hormone (TSH)
Melanotropin releasing hormone (MRH) is made in the ____ and stimulates the release of _____
hypothalamus; melanotropin
Kisspeptin is made in the ___ and plays a role in initiating secretion of _______
hypothalamus; gonadotropin-releasing hormone (GnRH)
The suffix -tropin or -tropic means
nourishing
Dopamine has (excitatory/inhibitory) actions in endocrine system
inhibitory (excitatory NT)
In the endocrine system, dopamine acts as a primary ______ hormone
prolactin-inhibitory hormone
Somatostatin (GHIH) is made in the ____ and acts to inhibit secretion of ____ and ____
hypothalamus; GH and thyroid-stim. hormone
(T/F) all hypothalamic hormones go through the pituitary
TRUE
Neurohormones from hypothalamus reach anterior pituitary via ______
the portal system
Neurohormones from hypothalamus reach posterior pituitary via _____
direct innervations!
Adrenocorticotropic hormone (ACTH) is released from the _____ and stimultaes synthesis and release of ___, ___ and ___ from adrenal glands
anterior pituitary; glucocorticoids, mineralcorticoids, and androgenic steroids
Growth hormone is released from the ____ and acts to promote ___
anterior pituitary; linear growth
Prolactin (PRL) is released from the ____ and promotes ______
anterior pituitary; additional breast dev and milk synthesis
Thyroid stimulating hormone (TSH) is released form the _____ and stimulates release of ___ hormone
anterior pituitary; thyroid hormone
Luteinizing hormone (LT) and follicle stimulating hormone (FSH) are released from the ___ and regulate function of _____
anterior pituitary; gonads
Hypothalamic projections are shorter into (anterior/posterior) pituitary
anterior! (posterior is quicker bc longer projections that directly innervate pituitary)
____ and ____ are stored in vesicles @ axon terminals of posterior pituitary
oxytocin and vasopressin
Vasopressin (antidiuretic hormone; ADH) acts to ____
retain water in body! (constricts blood vessels during blood loss)
Oxytocin plays a role in ___
- reproductive functions (eg contractions)
- suckling reflex
The pineal gland’s main function is related to ______
control of circadian cycle of sleep/wake by secreting melatonin
Melatonin is synthesized from ____
serotonin!
What did prof say the thyroid gland looks like?
bubble tea
Low levels of dietary ___ can result in reduced thyroid function and hypertrophy manifested as _____
iodine; swelling of neck
4 key functions of thyroid hormones triiodothyronine (T3) and thyroxine (T4)
- reg. of body metabolism
- control of dev. of brain and nervous system
- sexual maturation
- temperature regulation (varies thru seasons – why you feel colder at same temp in nov vs jan)
Hyperthyroidism is an (over/under) active thyroid. This can cause:
OVER (can cause weight loss, hand tremor, fast HR, weaker periods)
Hypothyroidism is an (over/under) active thyroid. This can cause:
UNDER (can cause weight gain, constipation, fatigue, cold sensitivity– Ronaldo had this)
____ and ___ are both protein hormones of the thyroid and are directly controlled by blood Ca levels
parathyroid and calcitonin (CT)
The pancreas consists of mostly _____ cells that produce and secrete digestive juices into intestines. It also contains islands of ___ tissue called ______.
exocrine; endocrine tissue called islets of Langerhans
Islets of Langerhan contain 4 cell types:
- alpha cells
- beta cells
- theta cells
- polypeptide secreting cells
Alpha cells in the pancreas produce _____ which acts in opposition to ____
glucagon; insulin (increases blood levels of glucose)
Beta cells in the pancreas produce ____ which is the only known hormone that can _____
insulin; reduce blood sugar
Theta cells in the pancreas produce ____ which inhibits the release of ___ and ___ locally in the pancreas
somatostatin; insulin and glucagon
Distinguish diabetes type 1, 2, (and 3)
T1: genetic, shows up early in life, immune system destroys insulin producing cells in pancreas (beta cells)
T2: lifestyle related, body can’t make enough insulin bc you’re consuming too much sugar OR insulin you make doesn’t work properly
T3: alterations of metabolism in brain very common in Alzheimers
The adrenal glands sit on top of the ____
kidneys
The adrenal cortex has distinct cellular zones:
- zona ____ marked by whorls of epithelial cells
- zona ____ in which epithelial cells are organized in orderly bands
- zona ____ where epithelial cells have disorganized appearance
- glomerulosa
- fasciculata
- reticularis
Hormones from the adrenal medulla receive info via ___
Hormones from the adrenal cortex receive info via ____
innervations
bloodstream
What are the 3 monoamine hormones released by the adrenal medulla? These function as part of the ___ NS
- epinephrine, norepinephrine, dopamine
- autonomic NS
____ is released from the zona glomerulosa of the adrenal cortex in response to low blood sodium levels
aldosterone
___ are released from the zona fasciculata of the adrenal cortex in response to ACTH stimulation from anterior pituitary
glucocorticoid hormones (steroids, lipid based)
___ are often released from the zona reticularis of the adrenal cortex
sex steroid hormones
Which part of the adrenal gland responds mainly to acute stressors and which to long term stress?
- acute: medulla (epinephrine, norepinephrine, dopamine, enkephalins)
- prolonged: cortex (aldosterone, glucocorticoid, sex steroid)
What are the 2 main functions of the gonads?
- production of gametes
- production of hormones
Hormones produced by the gonads are primarily ___ hormones
steroid
___ cells are interstitial cells btw seminiferous tubules in testes that produce androgens in response to LH from anterior pituitary
Leydig
What are the 3 main functional subunits of the ovaries
- Follicles: epithelial cell lined sacs that contain an egg
- Corpora lutea: secrete progestogens which support uterine lining
- Stroma: connective tissue of endocrine glands
Why do we say endocrine cells in the gut have a primitive organization?
- scattered throughout the gut
What are the 4 main gastrointestinal hormones?
- Secretin: stimulates pancreas to help digestion
- Cholecystokinin (CCK): may be involved in satiation
- Gastrin: induces secretion of water/electrolytes by stomach, pancreas, liver
- Ghrelin: stimulates GHRH release from ant. pituitary
Negative feedback: a regulatory system that tends to ____ a process when its effects are pronounced by ____
Positive feedback: a regulatory process that tends to ____ an ongoing process by ______ in response to the end product
stabilize; reducing its rate or output
accelerate; increasing production
Up-regulation: a process similar to (pos/neg) feedback in which a hormone causes _____
Down-regulation: (under/over)production of a hormone can cause _____ or _____
positive feedback; increase in production of receptors for that hormone
OVERproduction; occupation or reduce # of hormone receptors
When a hormone binds to a receptor, it forms the _____
hormonal complex
