Physiology-Endocrine System

Front 1

What is the "immediate" function of the endocrine system?

Back 1

Maintain homeostasis despite changes in internal/external environment, and includes regulating metabolism.

Front 2

What are the long term functions of the endocrine system?

Back 2

Initiate and/or regulate growth and maturation and the overall reproduction process (making and taking care of baby).

Front 3

What are the similarities between the endocrine and nervous systems?

Back 3

-use cells that secrete something as a communicator
-secrete substances into a space where it reaches another cell
-requires receptors on surface of target cell
-share SOME of the same chemicals

Front 4

What are the differences between the endocrine and nervous systems?

Back 4

-Endocrine system is slower, can target cells any distance away, and has a prolonged effect on its target.
-Nervous system is immediate, only targets adjacent cells and only has an immediate effect on target.

-Exception: epinephrine on heart rate

Front 5

What does the term "neuroendocrine" control refer to?

Back 5

When the endocrine and nervous system closely interact together to achieve goals.

Ex: suckling reflex

Front 6

Name some organs that have endocrine and non-endocrine functions.

Back 6

Kidney, heart, gonads, pancreas, stomach, small intestine, etc.

Front 7

Name some organs that have solely endocrine functions.

Back 7

Thyroid gland, parathyroid gland, adrenal gland, pineal gland.

Front 8

(T/F) One endocrine gland can make multiple hormones with differing functions

Back 8

TRUE

Front 9

(T/F) The same chemical cannot be a hormone and a neurotransmitter

Back 9

FALSE. It CAN be both.

Ex: Norepinephrine

Front 10

What is an example of a hormone that can be secreted by multiple endocrine glands? Where is it made?

Back 10

Somatostatin. Produced by hypothalamus and certain pancreatic cells.

Front 11

Is it possible for the same hormone to have multiple target sites and induce different effects at each site?

Back 11

Yes.
Example: Vasopressin/ADH

Front 12

(T/F) A single target cell can respond to multiple hormones.

Back 12

TRUE. Examples:
-hepatic cells respond to insulin AND glucagon
-ovaries respond to FSH and LH

Front 13

What is the definition of a hormone?

Back 13

Messenger substance produced by one or multiple organs/tissues/cells that is released into the bloodstream to target a distant site

Front 14

What are the 4 types of hormones NOT transported by the blood?

Back 14

Paracine substances (diffuses through tissues to adjacent cells), autocrine substances (acts upon itself), exocrine effectors (released into a cavity) and neurotransmitters.

Front 15

What are the 5 common characteristics of "all" hormones?

Back 15

1. Circulate and effective at LOW plasma concentrations
2. Effective at low concentrations bc of amplification of its signal
3. Specificity of action due to specificity of receptor
4. Altering number/type of receptors allows regulation of hormone
5. Liver and kidney are primary organs involved in hormone excretion

Front 16

What's the difference between hormone degradation and inactivation?

Back 16

Degradation: Only involved "used" hormones, takes place intacellularly in target cell and excreted by kidney.

Inactivation: Only involved "unused" hormones and takes place mainly in liver.

Front 17

What are the 4 major groups of hormones? Which is the most abundant?

Back 17

Prostaglandins (prostanoid), Amine, Steriod and Protein/Peptide.

Protein/Peptide is the most abundant.

Front 18

What are prostaglandins made from and where are they made?

Back 18

Made from arachidonic acid in a wide variety of cells and organs throughout body.

Front 19

What are some characteristics of prostaglandin production/release?

Back 19

-immediately released into systemic circulation or intersitial fluid after synthesis
-chemically instable and rapidly metabolized
-action is limited to adjacent cells (paracrine)

Front 20

What are some important actions of prostaglandins?

Back 20

-sensitive pain fibers
-generate fever
-(+/-) affect contraction of smooth muscle (vascular, GI, uterine)

Front 21

What are the 3 major categories of amine hormones?

Back 21

1. Serotonin: tryptophan derived
2. Catecholamines: tyrosine derived
3. Thyroid hormones: tyrosine derived

Front 22

Where are protein hormones made?

Back 22

Like other proteins, on the RER

Front 23

What's special about protein hormones? Where are they stored?

Back 23

They're WATER soluble. Can be stored in membrane bound storage (secretory) vesicles within the cell of origin

Front 24

How are protein hormones made active?

Back 24

Since precursors are larger than finished products, portions are cleaved off to make hormone active.

Front 25

How are protein hormones secreted?

Back 25

Storage vesicles becomes secretory, migrate to cell's surface membrane and exocytose hormone into extracellular fluid.

Front 26

(T/F) Protein hormones require carrier proteins to be transported through plasma.

Back 26

FALSE. Because they are WATER soluble, protein hormones are simply transported dissolved within the plasma

Front 27

How do protein hormones cause their target action?

Back 27

Since protein hormones are water soluble, they cannot get into the cell themselves, so their target receptors are one the cell surface membrane. By using a second messenger (like cAMP), the message is able to reach the inside of the cell.

Front 28

Are protein hormones' action considered rapid or slow? Why?

Back 28

They are rapid because the protein hormone action is to change PRE-EXISTING inactive proteins to an active form. (they don't have to make anything, pro-enzymes already exist!)

Front 29

What are the 2 types of steroid hormones?

Back 29

Sex hormones (estrogen, progesterone, androgens) and adrenocortical hormones (glucocorticoids and mineralocorticoids)

Front 30

How are steroid hormones synthesized?

Back 30

Mostly cholesterol derived

Front 31

(T/F) Cells of the adrenal gland have a little bit of the enzymes that control sex hormone production and gluco- or mineralocorticoid production.

Back 31

TRUE

Front 32

What's special about the release of steroid hormones?

Back 32

Basically they are released as they are produced.They're lipid soluble so they freely diffuse out of cell membrane once made (no external cue needed). For this reason, they also cannot be stored

Front 33

(T/F) Steroid hormones can freely move through plasma unassisted.

Back 33

FALSE. They are lipophilic and cannot move freely in plasma. Must be bound to transport proteins!

Front 34

What are the types of binding proteins for steroid hormones? How abundant are they?

Back 34

-Specific binding proteins (high affinity, but low capacity). Not abundant.
-General binding proteins (low affinity, but high capacity). Ex: albumins--VERY abundant

Front 35

What regulatory effects do binding proteins have on steroid hormones?

Back 35

1. act as a storage pool, only 1% is usually unbound
2. increases plasma half-life (decreases renal clearance and only free form can be degraded)
3. helps regulate hormone action (only unbound can exert effect)
4. reduced #s of binding proteins affect amount of free hormone

Front 36

Where are the receptors for steroid hormones?

Back 36

Intracellular. Either free in the cytosol or within nuclear membrane.

Front 37

Is steroid hormone action rapid or slow? Why?

Back 37

Slow. Because the eventual target of the hormone is the DNA within the nucleus. It alters gene expression to direct synthesis of a new protein, de novo.

Front 38

What are the structures involved in hormone production and action?

Back 38

Hypothalamus--> Pituitary gland --> Target Organ

Front 39

What is the goal of negative feedback?

Back 39

Bodily homeostasis

Front 40

What are the 3 forms of negative feedback? Describe them.

Back 40

1. long loop: feedback comes from the target gland and goes back to the pituitary or hypothalamus
2. short loop: feedback comes from the pituitary and goes back to hypothalamus
3. ultra short loop: feedback comes from the hypothalamus and acts on itself

Front 41

What is the goal of positive feedback?

Back 41

NOT bodily homeostasis. Goal is a specific, DEFINITE endpoint

Front 42

What is positive feedback?

Back 42

When hormone secretion or action INcreases hormone secretion until endpoint is reached.

Front 43

What are some of the functions of the hypothalamus?

Back 43

Homeostasis, endocrine activity and some somatic functions

Front 44

What is the median eminence?

Back 44

Ventral extension of hypothalamus housed inside the cranial vault. Leads into pituitary

Front 45

What are the 2 parts of the pituitary stalk?

Back 45

Infundibular stalk and the Pars tuberalis

Front 46

What is the infundibular stalk?

Back 46

ventral extension of the median eminence and emerges from cranial vault to suspend the posterior pit. from the brain

Front 47

What is the pars tuberalis?

Back 47

dorsal extension from the anterior pituitary that wraps around the infinbibular stalk

Front 48

Which part of the pituitary gland does the hypothalamus extend ventrally into and form?

Back 48

The POSTERIOR pituitary gland

Front 49

During embryological development what are the two contributing parts to the pituitary gland?

Back 49

Infundibulum (nervous origin) and oral diverticulum (oral cavity origin)

Front 50

What does the infundibulum form?

Back 50

The infundibular stalk and ALL of the posterior pituitary gland

Front 51

What does the oral diverticulum form?

Back 51

The pars tuberalis, intermediate lobe, and the anterior pituitary gland

Front 52

What is the only part of the pituitary gland that does NOT have a direct arterial supply?

Back 52

the anterior pituitary

Front 53

How does the anterior pituitary get its vascular supply?

Back 53

The hypophyseal portal system

Front 54

How does the hypothalamus communicate with and control the anterior pituitary gland?

Back 54

The hypophyseal portal system

Front 55

(T/F) Substances and blood can be transported directly from the median eminence to the anterior pituitary gland

Back 55

TRUE

Front 56

How do hormones released from the anterior and posterior pituitary gland attain systemic circulation?

Back 56

Both regions drain their own veins into systemic circulation

Front 57

Where are the hormones produced by the hypothalamus, related to the anterior pituitary, get released? What do they target?

Back 57

Released into the pituitary circulation and target ENDOCRINE cells in the anterior pituitary gland

Front 58

Where are the hormones produced by the hypothalamus, related to the posterior pituitary, get released? What do they target?

Back 58

Released into systemic circulation at the posterior pituitary and target NON-ENDOCRINE cells in the peripheral body

Front 59

(T/F) The hypothalamus indirectly communicates with the posterior pituitary.

Back 59

FALSE, its a DIRECT tissue connection by way of two hypothalamic nuclei extentions

Front 60

Does the posterior pituitary itself make hormones?

Back 60

NO! it just stores and releases those made by the hypothalamus

Front 61

(T/F) The hypothalamus communicates indirectly with the anterior pituitary gland.

Back 61

TRUE. no direct tissue connection, only vascular

Front 62

What is the pathway hormones travel along from the hypothalamus to the anterior pituitary?

Back 62

Hypothalamus --> Median eminence Hypophyseal portal system--> Ant. Pit.

Front 63

(T/F) ALL hypothalamic hormones are peptide hormones.

Back 63

TRUE

Front 64

What are the hypothalamic hormones related to the posterior pituitary gland?

Back 64

oxytocin and vasopressin/ADH

Front 65

What is a "factor"?

Back 65

Hormone made by the hypothalamus that affects the anterior pituitary (causes it to produce and/or release other hormones)

Front 66

What does a releasing factor (hormone) do?

Back 66

Made to control the anterior pituitary and causes it to release and/or produce a particular stimulating hormone

Front 67

What are the releasing factors of the hypothalamus that ALL target that anterior pituitary?

Back 67

1. Thyrotropin Releasing Hormone
2. Corticotropin Releasing Hormone
3. Growth Hormone Releasing Hormone
4. Gonadotrophin Releasing Hormone
5. Prolactin Releasing Hormone

Front 68

What are the inhibiting factors of the hypothalamus that ALL target the anterior pituitary?

Back 68

1. Growth hormone inhibiting hormone
-AKA: SOMATOSTATIN
2. Prolactin Inhbiting Hormone

Front 69

What is the main product of the intermediate lobe of the hypothalamus?

Back 69

Melanocyte Stimulating Hormone. Affects skin pigmentation/feather coloration, etc. Also responsible for seasonal changes of coloration

Front 70

Considering the posterior pituitary hormones are released directly into the blood, do they need releasing/inhibiting hormones?

Back 70

NO

Front 71

What does ADH/Vasopressin do?

Back 71

-Overall: regulation of body fluid volume and osmolarity and contributes to blood pressure regualtion.
-ADH-promotes water retention by kidneys
-Vasopressin-contraction of arteriole smooth muscle

Front 72

What does oxytocin do?

Back 72

stimulation of MILK EJECTION only!
-also stimulates uterine contraction and pair bonding and maternal behavior

Front 73

What is unique about oxytocin regulation?

Back 73

It uses POSITIVE feedback and signals originate at PERIPHERY (neuro-endo stimulation).

Front 74

What do all cells in the ant. pit. have?

Back 74

receptor for a specific releasing hormone and machinery to make one type of stimulating hormone

Front 75

What are the 2 functional groups of anterior pit. hormones?

Back 75

1. Those affecting NON endocrine targets (like body in general and mammary gland)
2. Those affecting endocrine targets (like adrenal cortecies, thyroid gland and gonads)

Front 76

What hormones made by the ant, pit. have NON-endocrine targets?

Back 76

Growth hormone & prolactin

Front 77

What hormones made by the ant, pit. have endocrine targets?

Back 77

Corticotropins, Thyroid Stimulating Hormones, Follicle Stimulating Hormone and Lutenizing Hormone

Front 78

What are the NON growth related effects of Growth Hormone?

Back 78

-mobilize fat stores as primary energy source, thus sparing glucose (leave it for the brain)

Front 79

(T/F) The DIRECT effect of growth hormone is NOT bodily growth, it causes the release of somatomedins

Back 79

TRUE

Front 80

Where is somatomedin made and what is it's overall effect?

Back 80

Made in liver, overall effect=GROWTH

Front 81

What does prolactin do?

Back 81

Induces and maintains milk PRODUCTION!

Front 82

What does cortiotropin do?

Back 82

Stimulates adrenal cortical growth and activity and increases plasma levels or corticosteriods

Front 83

What does FSH do in females and males?

Back 83

Females: promotes follicle growth and estrogen production
Males: promotes spermatogenesis by seminiferous tubules

Front 84

What does LH do in females and males?

Back 84

Females: promotes ovulation and progesterone production by ovulated follicle
Males: promotes testosterone production by interstitial cells

Front 85

Why is skin darkening a sign of conditions with HIGH plasma ACTH (Addison's)?

Back 85

Bc ACTH contains the exact AA sequence of melanocyte stimulating hormone within its own structure

Front 86

What does FSH do in females and males?

Back 86

Females: promotes follicle growth and estrogen production
Males: promotes spermatogenesis by seminiferous tubules

Front 87

What does LH do in females and males?

Back 87

Females: promotes ovulation and progesterone production by ovulated follicle
Males: promotes testosterone production by interstitial cells

Front 88

Why is skin darkening a sign of conditions with HIGH plasma ACTH (Addison's)?

Back 88

Bc ACTH contains the exact AA sequence of melanocyte stimulating hormone within its own structure