Endocrine System (Dat)

Front 1

What are the 3 types of hormones?

Back 1

-Peptide Hormones
-Steroids
-Amino Acid Derived

Front 2

Peptide Hormone Characteristics

Back 2

-Hydrophillic
-Made in the RER (preprohormone) and cut in ER lumen (prohormone) and packaged into vesicles by Golgi
-Bind to membrane recptors and activate 2nd messengers
-RAPID BUT SHORT-LIVED

Front 3

Steroid Hormone Characteristics

Back 3

-Hydrophobic
-Made from cholesterol in Smooth ER and immediately secreted from cell
-Travel bound to protein plasma and diffuse diffuse through cell membranes
-Activate cytosolic proteins or alter txn of [protein] in nucleus
-SLOW BUT LONG-LIVED

Front 4

Amino Acid Derived Hormones
(Tyrosine-derived)

Back 4

Mimic either peptide or steroid hormonal characteristics
-Peptide: Catecholamines (adrenaline, norepinephrine)
-Steroid: Thyroid Hormones; T3, T4

Front 5

Is the Pancreas an endocrine or exocrine gland?

Back 5

Both!
-Exocrine: secretes digestive enzymes and biocarbante through ducts into gastrointestinal tract
-Endocrine: secretes hormones into bodily fluid (insulin glucagon, and somatostatin)

Front 6

What cells in the pancreas secrete endocrine hormones?

Back 6

Islet cells; "The islets of Langerhans"
-Alpha: secrete insulin
-Beta: secrete glucagon
-Delta: secrete somatostatin

Front 7

Insulin (4 main functions)

Back 7

1. Increase cellular uptake of glucose
2. Decrease blood glucose levels
3. Promote glycogen production in liver
4. Increase protein & triglyceride synthesis

Front 8

Glucagon

Back 8

Opposite effects of Insulin.
1. Increases blood glucose levels by:
a) Promoting glycogenolysis and gluconeogensis in liver
2. Also promotes lipid breakdown
**Does Not Decrease Cellular uptake of Glucose**

Front 9

Somatostatin

Back 9

Regulates endocrine system by inhibiting digestive processes--takes longer for nutrients to be absorbed
-Inhibits both insulin and glucagon

Front 10

What is hyperglycemia?

Back 10

Excessively high blood glucose levels caused by:
-diminished insulin secretion or activity

Front 11

What is hypoglycemia?

Back 11

Excessively low blood glucose levels caused by:
-elevated insulin levels
-insufficient glucagon in body

Front 12

Two adrenal glands are:

Back 12

1. Cortex
2. Medulla

Front 13

Adrenal Cortex

Back 13

-Produces steroid hormones:
a) mineralcorticoids i.e. aldosterone (most outer)
b) glucocorticoids i.e. cortisol (inner)
c) sex hormones (most inner)

Front 14

Aldosterone

Back 14

What? Steroid mineralcorticoid increasing:
1) urinary excretion of K+
2) Interstitial Na+ concentration
3) 2° effect: water conservation, ↓urine output
How and where?
-Increase Na+/K+ pump activity in the distal convoluted tubule of the kidney

Front 15

Cortisol

Back 15

Glucocorticoid stress hormone regulated by ACTH of the anterior pituitary gland which is further regulated by the hypothalmus.
-↑ blood sugar through gluconeogenesis, cardiac contractions, water retention & anti-inflammatory
-↓ immune activity

Front 16

Adrenal Medulla

Back 16

Secretes the catecholamine peptide hormones: epinephrine & norepinephrine.
-Increases heart rate, blood pressure, increase alertness

Front 17

Thyroid

Back 17

Secretes both tyrosine-derived (T3/T4) and peptide hormones (calcitonin).

Front 18

Other names for T3 and T4

Back 18

Triiodothyronine and Thyroxine

Front 19

T3 and T4 function

Back 19

-Generalized increase in metabolism
-Stimulate O2 demand, heat production, and growth/development
Regulated by anterior pituitary (TSH) and hypothalamus
--Negative Feedback Inhibition on TSH and TRH

Front 20

Hypothyroidism

Back 20

Inaqdequate production of thyroid hormones causing:
-Decrease in metabolism→overweight,
-Goiter: increase in growth for iodine absorption

Front 21

Calcitonin

Back 21

Pep. hormone produced in parafollicular cells of thyroid
-Reduces blood Ca++ levels by:
-Increasing Ca++ deposition in bones
-Decreasing kidney Ca++ resorption

Front 22

Parathyroid Hormone (PTH)

Back 22

-Opposite effects of calcitonin.
-Responds to low Ca++ blood levels and increases blood Ca++ concentration by:
1) ↑ bone release of Ca++
2) ↑ Intestinal and Kidney Ca++ uptake

Front 23

Ovaries

Back 23

Site of oogenesis in women and responsible for progesterone and estrogen synthesis

Front 24

Menstrual Cycle

Back 24

Series of hormonally induced events preparing female for pregnancy. Described by changes with respect to ovaries (ovarian cycle) or endometrial lining (uterine cycle). Bleeding marks first 1st day (flow).

Front 25

Phases of Ovarian Cycle

Back 25

1) Follicular- Anterior pituitary releases FSH & LH that stimulates rapid growth of follicle. Follicle secretes estrogen that stimulates LH (+ feedback) & causes luteal surge (day 14)
2) Ovulation: Mid-cycle release of the egg
2) Luteal Phase-After ovulation, corpus luteum remains secreting progesterone & estrogen day 14-28
3) Flow-shedding of uterine lining; corresponds w/ beginning of follicular phase

Front 26

Phases of the Uterine Cycle

Back 26

(1) Menses- shedding of uterine lining; same time as early follicular phase
(2) Proliferative Phase- Until day 14. Estrogen secretion from follicle induces proliferation of endometrium
(3) Secretory Phase- Progesterone (& estrogen) from corpus luteum promotes rapid thickening & vascularization of endometrium--final 14 days

Front 27

What happens if mature ovum is not fertilized?

Back 27

~13 days after ovulation (day 27)
-corpus luteum degenerates into corpus albicans
-progesterone/estrogen not available so endometrium severs (~5 days)---> new proliferative phase

Front 28

What happens if mature ovum is fertilized?

Back 28

~day 14, developing placenta secretes hCG upon implantation that keeps corpus luteum from degenerating until end of 1st trimester when placenta takes over

Front 29

Where is the mature ovum usually fertilized by sperm?

Back 29

Oviduct (fallopian tube)
-more specifically, the AMPULLA of the uterine tube

Front 30

Luteal Surge

Back 30

Sudden ↑ of LH associated with release of ovum (haploid cell produced by 1st meiotic division of 1° oocyte)

Front 31

Corpus Luteum

Back 31

Remnant of ruptured follicle. Secretes progesterone and estrogen that promotes endometrium growth.

Front 32

hCG

Back 32

Human chorionic gonadotropin.
-secreted from placenta upon implantation of fertilized ovum that keeps corpus luteum from degenerating until end of 1st trimester when placenta takes over progesterone/estrogen secretion

Front 33

Primary Follicle

Back 33

-FSH stimulates growth of granulosa cells around 1° ooctye.
-g cells secrete viscous zona pellucida around egg

Front 34

Secondary Follicle

Back 34

LH--->follicle to complete first meiotic division in which theca cells arise from interstitial tissue around 1° follicle to form 2° follicle.

Front 35

Theca cells

Back 35

Stimulated by LH and release androgen that is converted to estradiol by granulosa cells (+FSH) that is secreted into blood

Front 36

Gonadotropin releasing hormone (GnRH)

Back 36

Secreted from hypothalamus. Responsible for secretion of FSH & LH from anterior pituitary gland.

Front 37

Where does spermatogenesis (gametogenesis) take place?

Back 37

Seminiferous tublules of the testes

Front 38

Gonads

Back 38

Ovaries or Testes

Front 39

Name of male germ cells as it grows?

Back 39

(1) Spermatogonia or spermatogonium
(2) 1° Spermatocyte
(3) Spermatids
(4) Spermatozoa or spermatozoon

Front 40

Leydig cells

Back 40

-Interstitum tissue of seminiferous tubules
-secretes testosterone when stimulated by LH

Front 41

ICSH

Back 41

interstitial cell stimulating hormone
-another name for LH in males
-becomes plentiful upon puberty

Front 42

Testosterone

Back 42

Primary male androgen
-Promote spermatogenesis
-Promotes secondary sex characteristics (i.e. deep voice, facial/pubic hair, penis enlargement)

Front 43

Spermatogenesis

Back 43

Division of spermatogonia within the seminferous tubules to produce haploid spermatozoa

Front 44

Sertoli Cells

Back 44

-Nurture and surround spermatocytes and spermatid
-Stimulated by FSH
-Secrete inhibin which blocks FSH (@ant. pit./hypothal)

Front 45

Inhibin

Back 45

-Peptide hormone that secreted from sertoli cells -inhibits release of FSH from anterior pituitary gland

Front 46

When do male germ cells form the "head, midpiece, and tail" configuration?

Back 46

From spermatid (regular cell characteristics) to a spermatozoon.

Front 47

Acrosome

Back 47

Contains lysosome-like enzymes for penetration of egg during fertilization

Front 48

Anatomy of Spermatozoon

Back 48

Head-contains nucleus and acrosome
Midpiece- contains mitochondria to provide movement of tail
Tail- standard 9+2 microtubule arrangement

Front 49

Epididymis

Back 49

Coiled tube attached to each testis
-site where spermatozoon mature

Front 50

Where is semen produced?

Back 50

1. Seminal valves-fructose and prostaglandins
2. Prostate- milky alkaline fluid
3. Cowper's glands (bulbourethral glands)

Front 51

Path of Ejaculation

Back 51

Spermatozoon--->vas deferens---->urethra--->out of penis

Front 52

At what stage do 1° oocytes become arrested?

Back 52

Prophase I of meiosis

Front 53

What two cells are formed at the end of meiosis I?

Back 53

Secondary oocyte and polar body (both haploid)

Front 54

Polar body

Back 54

Formed after meiosis I from oocyte
-contains less cytoplasm (nutrients)
-may continue with meiosis II but ultimately disintegrates

Front 55

What stimulates the release of GnRH?

Back 55

Low levels of estrogen/progesterone in the blood monitored by the hypothalamus?

Front 56

What causes termination of reproductive cycle in females?

Back 56

Negative feedback from high levels of estrogen/progesterone inhibits FSH/LH secretion through inhibiting GnRH at hypothalamus

Front 57

Endocrine functions of Hypothalamus

Back 57

-Releases hormones that control secretions from the pituitary gland
-Regulating control center for endocrine and ANS

Front 58

Tropic Hormone

Back 58

Hormones that target other endocrine glands

Front 59

Name the 6 (or 7) peptide hormones from the anterior pituitary gland

Back 59

"FLAT PEG"
1. FSH
2. LH
3. ACTH (adrenocorticotropic hormone)
4. TSH
5. PTH
6. Endorphins
7. Growth Hormone (hGH)

Front 60

All hormones secreted from the anterior pituitary are tropic and peptide hormones (T/F)

Back 60

False.
All are peptide hormones, however, GH and Prolactin are non-tropic hormones

Front 61

TSH or thyrotropic hormone

Back 61

Thyroid Stimulating Hormone
-stimulates thyroid to release of T3, T4 via cAMP
-responsible for increase in thyroid size/number, and secretion rate of T3, T4

Front 62

ACTH

Back 62

Adrenocorticotropin Hormone
-stimulates adrenal cortex to release glucocorticoids, mainly CORTISOL, via cAMP

Front 63

LH

Back 63

Luteinizing Hormone
-Stimulates gonads (ovaries or testes) to promote sex hormone secretion (estrogen/progesterone, testosterone)
-stimulates gamete production (Leydig cells)

Front 64

FSH

Back 64

Follicle stimulating hormone
-stimulates follicle maturation
-stimulates sperm production (sertoli cells)

Front 65

Non-tropic hormones

Back 65

Hormones that directly stimulate target cells to induce effects (Prolactin, GH, Oxytocin)

Front 66

GH

Back 66

Growth Hormone
-Influences growth in most cells of the body
-Development of skeletal muscle, bones, and organs
-W/O GH----> abnormal development

Front 67

STH

Back 67

Somatotropin Hormone aka Growth Hormone

Front 68

Prolactin

Back 68

-Directly targets female breasts
-Stimulates breast development and milk production

Front 69

ADH and Oxytocin are produced at the posterior pituitary gland (T/F)

Back 69

False.
Produced in the neural soma of the hypothalamus and transported via vesicles down axons---> stored and released from posterior pituitary

Front 70

What are the two peptide hormones released from the posterior pituitary gland?

Back 70

1. ADH
2. Oxytocin

Front 71

ADH

Back 71

Antidiuretic hormone or Vasopressin
-stimulates water absorption at the collecting ducts of kidneys
-2° effects: ↑blood pressure, salty urine

Front 72

What inhibits ADH?

Back 72

Caffeine, beer

Front 73

Oxytocin

Back 73

-Smooth muscle contractions of breast lactating
Released at childbirth (parturition):
-Causes uterus to contract and push the fetus through birth canal
-Stimulates placenta to secrete prostaglandins--> more vigorous contractions of uterus

Front 74

Adrenal Cortex is responsible for the production of mineral/glucocorticoids...as well as sex hormones (T/F)

Back 74

True.
-Secretes low levels of sex steroids (mostly androgens)

Front 75

CRH

Back 75

Cortico Releasing Hormone
-secreted from hypothalamus and stimulates release of ATCH from posterior pituitary

Front 76

TRH

Back 76

Thyrotropin-releasing hormone
-produced in hypothalamus
-stimulates release of TSH from pituitary gland

Front 77

Two major divisions of feedback regulation

Back 77

(1) Simple Endocrine Reflex: physiological endpoint shutting off signal at endocrine gland
(2) Tropic Hormone feedback regulation: regulating release from higher organs (hypothalamus, pituitary)

Front 78

Progesterone

Back 78

Builds vascularization of endometrium for blastocyst implantation. Secreted by follicle, corpus luteum, and placenta. (also stored in the adrenal cortex,mostly males)

Front 79

What hormonal signal causes menstruation to begin?

Back 79

High levels of estrogen and progesterone
Estrogen+Progesterone---|GnRH--->FSH+LH--->Corpus L.