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58 terms

Endocine System Anatomy Simple Review

Endocrine anatomy
STUDY
PLAY
Which of the following cells secretes calcitonin?

a. principle cells of the thyroid
b. parafollicular cells of the thyroid
c. oxyphil cells of parathyroid
d. principle cells of the parathyroid
b. parafollicular cells of the thyroid
Which region of the suprarenal gland manufactures and secretes epinephrine?

a. medulla
b. zona glomerulosa
c. zona fasiculata
d. zona reticularis
A. medulla under sympathetic control secretes nonepi and epi
What are the glands in the picture
parathyroid glands
Thyroid hormones T3 and t4 are store in which of the following?
a. herring bodies
b.colloid
c. principle cells of follicle
d. parafollicular cells
b colloid
WHich of the cells indicated secretes the hormone that lowers blood sugar.
A. (blue) beta cells
B. (pink cells) Alpha cells
C. (gray) delta cells
A. Blue = beta cells secrete insulin.
Which region of the hypophysis secretes hormones that effect the testis and ovary?
Pars distalis
The hormone vasopressin is released from which specific region of the hypophysis?
pars nervosa - neurohypophysis
melatonin is secreted by which of the endocrine organs?
pineal gland
Identify those portions of the hypophysis that arose from the roof of the oral cavity?
pars distalis up to stalk
What is D?
isthmus of thyroid
Features of Endocrine system
-Functions w/ nervous sys to regulate body processes and maintain homeostasis
-slower than neurological response (sometimes days.)
-Hormonal effects last sec, wks, mos
Exocrine - endocrine differences
Hormones
-organic substances secreted by a cell that have effect on function of another cells either close by or far away
-released into extracellular space to go to BV
-action restricted to target cells with receptors for them
Paracrine secretions
hormones travel short distance
Three types of Hormones
PAS
Protein
Amine
Steroid
Steroid
lipic with LDL nucleus
(admi oral -IV)
Sex hormones, adrenal cortex hormones
Proteins
AA, bonded by peptide chain
-pituatary-parathyroid-calcitonin TG
(admin IV, InMusc, Subcutaneous)
Amine
AA with NO peptine bonds- has NH2 group
-thyroxine TG, Adrenaline ADRE, Melatonin Pineal
(admin oral-IV -or inhale
Control of Hormone secretions
-feedback (primarily)
Negative feedback
Endogland secretes hormone until target cells send message back that they have enough
This message inhibits secretion.
When singal inhib is low it starts to secrete again
Hypophysis
Master endocrine gland of body.
Located at brain attached to hypothalamus by stalk
Infundibulum
Stalk connecting hypophysis to hypothalamus
Components of Hypophysis Pituitary Gland
Adenohyphysis-Anterior lobe
Neurohypophysis-Posterior lobe
Adenohypophysis Components
Pars tuberalis (like tube at stalk)
Pars Intermedia (gone in humans)
Pars distalis (the sac) *most active
Adenohypophysis Hormones
GH, TSH, ACTH, FSH, LH PRO
G.L.A.F.T PRO
Nuerohypophysis
posterior lobe
Nervous portion derived from "down growth" of brain.
- Hormones synthesized in hypothalamic nuclei of brain. come down neuronal processes and stored in terminal azonal regions in neurohypophysis
Neurohypophysis components
infundibulum (by stalk)
pars nervosa
Hormones of Neurohypophysis
ADH (vassopressin)- decrease uring production anti-diuretic
OXYTOCIN (+feedback) contraction at birth; "love" and sexual arousal M and F
Two ways hormonal secretion is controlled
1. negative feedback system
2. nervous control
Organs effected by hormones of neurohypophysis
1. uterus
2. mammary gland
3. kidney
Thyroid Gland
Location: below larynx
Has 2 lateral lobes connected by isthmus
A-larynx, B/C-lateral lobes d-isthmus
ThyroidGL composition
Composed of follicles surrounded by cubodial epithelia.
Principal Cells=cubodial epithelia
Principal cells surround
follicles - named colloid
Hormones of ThyGl
Thyroxine (Amine ) T4 (iodine)
Triiodothyronine (amine) T3 more potent than T4
Calcitonin (produced by cells between folicles) from parafollicular cells.
T4 - T3
-Regulate metabolism
-iodine necessary for them to form
-synthesized by principal cells pr THYGL follicles
-synthesized and stored in follicle as colloid until released.
Colloid
The morphology of T3 and T4 store in the follicle by the ThyGl until their release.
Calcitonin
-made by parafollicular cells
-regulates calcium - decreases blood Ca by inhibiting osteoclasts and increases secretion of Ca by the kidneys.
No bone death - Ca released kidney
Hypothyroidism
-iodine deficiency
-thyroid destruction
-inflammation
Pathway of hormone release
TRH (hypothalamus)--->
TSH (adenohypophysis)-->
TH (adrenal cortex)
parathyroid Glands
Like butterfly, on posterior surface of Thy GL.
Two superior
two inferior
Small yellow-brown organs-separated from THYGL by capsulate
Parathyroid cells
Principal cells (chief cells) synthesize the hormone)
-oxyphil cells secrete nothing but support chief cells.
Effects of parathyroid Hormon PTH
-increase in blood Ca
stimulates osteoclasts to reabsorb bone and causing kidneys to retain calcium
Bone death , kidney Ca retention
(inhibits urinary secretion of Ca, and increases interstitial Ca resorption)
Suprarenal Glands
Sits on top of kidneys
Two components
-Cortex
-Medulla
Suprarenal cortex has 3 layers
GFR
ZONA-
Glomerulosa-mineralcoritcoids (Na and K regulation)
Fasciculate-glucocorticoids (affects glucose metabolism-
Reticularis-gonadocorticoids (sex hormones) androgens, estrogen
Cushings syndrome
Hypersecretion of Adrenal Cortex
-Edema
_Fat shoulders
-Hyperglycemia
Pathway for Suprarenal Hormones
CRH (hypothalamus)-->
ACTH (Adenohypophysis)-->
Cortisol (adrenal cortex)
Pancreas
98 % exocrine 2 % endocrine (islets of Langerhans.)
Islets of Langerhans
groups of epithelial cells associated wiht BV.
Three types of cell in an islet
Alpha cells (pink) -glucagon- raise blodd glucose by breaking glycogen to glucose and then releasing it.

Beta cells (blue) secrete insulin - lowerd blood glucose levels by removing glucose and storing it as glycogen

Delta cells- orange- secrete somatostatin inhibits both insulin and glucagon.
Pineal Gland
Located deep in brain
-secretes melatonin
(decrease retina light =increase melatonin)
-function in circadian rhythms.
Thymus
anterior mediastinum in childhood
-regresses at puberty
-secrete thymosin
Thymosin
controls differentiation of T-cells
Ovaries
-Estrogen
-Progesterone
Testes
-interstitial cells of Leydig secrete testosterone.
What hormone is secreted by the parathyroid
gland and what is its function?
Parathryoid hormone (PTH)—increases free Ca2+ levels by increasing calcium absorption in the intestines, inhibiting Ca2+ secretion in the urine, and by increasing osteoclast activity in bone.
How are the parathyroid glands antagonistic to
the thyroid gland?
Release of PTH from the parathyroid hormone leads to an increase in free Ca2+ levels in the blood (reasons stated above in question 2416). However, calcitonin, which is released by the thyroid gland, decreases circulating levels of Ca2+ by inhibiting the bone-resorbing activity of osteoclast
What is the endocrine portion of the pancreas
called?
islets of Langerhans
What is the general anatomical arrangement of the suprarenal glands?
there is an outer cortex surrounding a medulla