Term
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Definition
release of hormone by endocrine gland
Ex: pituitary gland releases FSH/LH |
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Term
| What are the three pathways a hormone can be released? |
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Definition
Endocrine Communication
Neuroendocrine communication
Neural Communication |
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Term
| Neuroendocrine communication |
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Definition
Nerve directly releases a hormone into the blood system
Ex: oxytosin release can cause sperm moving |
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Term
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Definition
nerve is excited and directly synapses onto target organ, fastest way to activate
Ex: fight/flight (Ach & Norepinephrine) |
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Term
| What are the basic steps of a hormones mode of action? |
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Definition
paracrine -- hormone acts in response to cell
autocrine -- hormone released/acts on cell
intracrine -- stimulates with in |
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Term
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Definition
| similar molecular structure; binds to a hormone receptor and causes the same biological effect |
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Term
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Definition
| have greater afffinity for hormone receptor; blocks hormone access to receptor; causes weaker or inhibits activity |
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Term
| Explain how protein hormones act on a cell. |
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Definition
water soluble, can be secreted into blood vessel, but cannot penetrate cell membreane, so needs a specific receptor to enter. Then protein hormone activates 2nd activator (C AMP). This starts protein kynase which can either do protein synthesis or inhibit production.
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Term
| Examples of Steroid Hormones and how the act. |
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Definition
FSH > Granulosa cell > c AMP > Protein Kinase > Estrogen Produced
LH > Follicle > c AMP > Protein Kinase > Testosterone produced |
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Term
| How do steriod hormones act? |
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Definition
| They are not water soluble, so they need protein carrier to go through blood bu because of lipid structure, can go right through the cell membreane into the nucleus and act on receptor where they inhibit/secrete more protein |
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Term
| What are the three modes of hormone secretion? Give example of each. |
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Definition
Episodic -- GnRH (surge)
Basal -- GnRH (tonic)
Sustained -- Progesterone (most steriod this way) |
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Term
| What is the series break down the occurs from Cholesterol to estrogen? |
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Definition
| Cholesterol > Pregnencione > Progesterone (males start here) > Testosterone >(aromatase)> Estrogen |
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Term
| Reproductive Hormones Can cause |
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Definition
Release of other hormones
stimulation of gonads
sexual promotion
pregnancy maintenace
luteolysis |
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Term
| Strength of hormone depends on... |
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Definition
duration of secretion
half-life
receptor density
receptor-hormone affinity |
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Term
| What is HHP? What does it allow? |
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Definition
Hypothalamo-hypophyseal protal system. (Collection of blood system)
Allows minute amounts of hormones to act on the A.P. without dilution GnRH. |
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Term
What happens in the Follicular Phase?
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Definition
Proestrus ::~3 days in cattle:: (formation of ovulatory follicles, rising E2 production, regressing CL)
Estrus ::12-18 hrs in cattle:: (standing heat, max E2 production, ovulation) |
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Term
| What happenns in the Luteal Phase? |
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Definition
Metestrus ::6-8 days in cattle:: (conversion of CH to CL, rising progesterone)
Diestrus ::~9 days in cattle:: (Max progesterone production, maternal recongnition, no embro=luteolysis) |
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Term
| What are causes of anestrus? |
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Definition
pregnancy
lactation (p4 would be high)
presence of offspring
season
stress
nutrition |
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Term
| What is the difference between spontaneous vs induced ovulators? |
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Definition
Spontaneous - ovulationis in response to hormonal changes
Enduced - requires stimulation of the vagina or cervix for ovulation to occur (activation of sensory nerves in the vagine or cervix causes increase firing of the hypothalamic neurons, causing a surge in GnRH) |
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Term
| Describe the formation of the CL |
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Definition
Granulosal and thecal cells collapse and interdigitate
P4 concentrations correlated with CL diameter
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Term
| Large luteal cells origninate from where? How do they grow? Small luteal cells? |
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Definition
Large: granulosal cells -- hypertrophy
Small: theca cells -- hyperplasia |
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