Endocrine System Flashcards

Question

Thyroid-Stimulating Hormone

Answer 1

- stimulates growth of thyroid gland and secretion of TH

Answer 2

- regulates stress response by stimulating adrenal cortex

Answer 3

females - stimulates milk **synthesis** after childbirth males - increases LH sensitivity, thus increasing testosterone secretion

Answer 4

AKA **Somatotropin** - promotes tissue growth

Answer 5

- involved in skin pigmentation

Answer 6

Via **releasing** and **inhibiting hormones** sent through the **hypothalamo-hypophyseal portal system**

Answer 7

- a system in which blood moves from organ to organ without first passing through the heart

Answer 8

Primary capillaries

Answer 9

Portal Venule - between hypothalamus and adenohypophysis

Answer 10

Secondary capillary bed | (in adenohypophysis)

Answer 11

**Posterior Pituitary** (AKA **Neurohypophysis**) - secretes **two hormones**: **ADH** and **Oxytocin**

Answer 12

**Anti-Diurectic Hormone** (AKA **Vasopressin**) - produced in hypothalamus, sent to neurohypophysis, secreted from there - **targets kidneys** to **increase water retention**, **reduce urine** and **increase blood pressure** - functions as **neurotransmitter**

Answer 13

- produced in hypothalamus, sent to neurohypophysis, secreted from there - stimulates **lactation** and **labor contractions** - possible role in **sperm transport** and **emotional bonding**

Answer 14

Via the **hypothalamo-hypophyseal tract,** a **neural connection** between the two glands - neuron cell bodies in the hypothalamus transport ADH and oxytocin via their axons to a capillary bed in the neurohypophysis

Answer 15

**thyroid gland** - the largest endocrine gland - secrete **thyroid hormones** which increase metabolic rate, etc. - located anterior and laterally to trachea, inferior to larynx - two lobes connected by the **isthmus** - bulbous inferiorly, tapered superiorly

Answer 16

**Isthmus** of the thyroid gland

Answer 17

**Thyroid Follicle** - microscopic pockets within thyroid filled with **colloid** and lined with simple cuboidal epithelial cells which release **T3** and **T4**

Answer 18

**T3** (tri-iodothyronine) and **T4** (thyroxine) * increase metabolic rate and O2 consumption * increase heat production via calorigenic effect * increase heart rate and contraction strength * increase respiratory rate

Answer 19

**Colloid**, AKA **thyroglobulin** - fluid within thyroid follicles containing precursors to thyroid hormones

Answer 20

**Parafollicular Cells** (AKA **Calcitonin** or **C Cells**) - found between cuboidal follicular cells - produce **calcitonin**

Answer 21

- hormone produced by parafollicular cells of thyroid - Decreases blood Ca²⁺, promotes Ca²⁺ deposition and bone formation (via osteo**_blast_** activity)

Answer 22

**follicular cells** - simple cuboidal epithelium - produce thyroid hormones

Answer 23

**Pineal Gland** (or body) - located in the posterior roof of the diencephalon - produces **melatonin**, which regulates sleep cycles - may play a role in the onset of puberty

Answer 24

**Parathyroid Glands** - located on posterior surface of thyroid - usually 4, up to 8 - produce **parathormone (PTH)** in their **chief cells**

Answer 25

AKA **Parathyroid hormone** or **parathyrin** - secreted by **chief cells** of parathyroid function: * increase blood Ca²⁺ levels * promotes synthesis of **calcitriol** (active form of vitamin D), thereby... * increasing digestive absorption of Ca²⁺ * decreasing urinary excretion of Ca²⁺ * increasing bone resorption (via osteo**_clasts_**)

Answer 26

- active form of vitamin D synthesized in the kidney when stimulated by PTH - increases Ca absorption and bone resorption, decreases Ca excretion, thus increasing blood Ca - opposes action of Calcitonin from parafollicular cells of thyroid

Answer 27

**parathyroid gland** **chief cells -** synthesize parathormone

Answer 28

**Adrenal Glands** - triangular gland embedded in adipose tissue on **superior surface of kidneys** - almost entirely **sympathetic innervation** - "two glands in one" - **adrenal medulla** deep to **adrenal cortex**

Answer 29

**adrenal medulla** - **neuroendocrine** tissue - **_Chromaffin Cells_** - **modified postganglionic sympathetic cells** division of ANS - create and secrete **Epinephrine**, **Norepinephrine** and some **Dopamine** - **exception** to long postganglionic axon rule in sympathetic ANS, **preganglionic sympathetic fiber runs into medulla**

Answer 30

- hormones produced and secreted by Chromaffin cells of the adrenal medulla - have some different effects but generally contribute to **fight-or-flight** response: * increase heart rate and BP * constrict skin and GI blood vessels * dilate smooth muscle * increase metabolism

Answer 31

**adrenal medulla** (chromaffin cells in spherical clusters)

Answer 32

- cells of the adrenal medulla which synthesize epinephrine or norepinephrine

Answer 33

**adrenal cortex** - glandular tissue of adrenals - makes up bulk of adrenal gland - secretes **corticoid hormones**

Answer 34

1. **Mineralocorticoids** from the **Zona glomerulosa,** specifically **Aldosterone** 2. **Glucocorticoids** from the **Zona Fasciculata**, specifically **Cortisol** 3. **Gonadocorticoids** from the **Zona Reticularis,** specifically **androgens and testosterone**

Answer 35

**Zona **_glomerul_**osa** of adrenal cortex - round arrangements of cells - make **mineralocorticoids**, ex: aldosterone

Answer 36

**Zona **_Fascicul_**ata** - middle, largest layer of adrenal cortex - **parallel cords** of lipid-rich cells - appear "bubbly" and usually stain lighter than other layers - creates **glucocorticoids**, ex: **cortisol**

Answer 37

**zona **_reticul_**aris** - innermost cortical layer next to adrenal medulla - narrow band of **small, branching cells** - produce **gonadocorticoids**, ex: androgens/testosterone

Answer 38

Pancreas - just inferior to stomach in posterior wall of ab. cavity - **mixed exocrine/endocrine** gland - **exocrine** cells produce **digestive enzymes** - **endocrine** cells grouped into **Islets of Langerhans,** which secrete hormones including: * **Glucagon** * **Insulin** * **Somatostatin** * **Pancreatic polypeptide**

Answer 39

- secreted by **alpha cells** of **pancreatic islets** - signals the liver to **break down glycogen** into glucose

Answer 40

- secreted by **beta cells** of pancreatic islets - signals cells to take up glucose, **controls blood sugar** levels

Answer 41

- released by **delta cells** of pancreatic islets - **decreases insulin & glucagon** release - **decreases growth hormone** release

Answer 42

- secreted by **F cells** (AKA **PP cells**) of pancreatic islets - **decreases pancreatic exocrine activity**

Answer 43

**Pancreatic Islet** (AKA **Islet of Langerhans**) - groupings of endocrine cells within the pancreas - five kinds of cells: * **alpha cells** (glucagon) * **beta cells** (insulin) * **delta cells** (somatotropin) * **F cells** (pancreatic polypeptide) * **epsilon cells** (ghrelin)

Answer 44

**anterior pituitary** - densely packed cells

Answer 45

**posterior pituitary (pars nervosa)** - unmyelinated axons + neuroglia

Answer 46

**Thymus** - produces hormones **thymopoietin** and **thymosins** which regulate development and maintenance of **immune function**

Answer 47

**Ovaries** - primary female sex organ - located retroperitoneally in abdomen, lateral to uterus at proximal end of fallopian tubes - produce female sex hormones **estrogen** and **progesterone** and **contain ova**

Answer 48

**Testes** - male sex organ located in scrotum - secrete **androgens (testosterone)** and **inhibin** - produces **sperm cells**

Answer 49

**Follicles** - **eggs** surrounded by **granulosa cells**

Answer 50

**Granulosa Cells** - cells within ovaries that produce **estrogen**

Endocrine System Flashcards

(76 cards)