anatomy: endocrine system

In the name of God

Anatomy:

Endocrine System

Moradian MD, MPH, PhD candidate

Tehran University of Medical Sciences

drmoradian@sums.ac.ir

2013

http://www.

emc.marico

pa.edu/fac

ulty/farabe

e/biobk/bio

bookendocr

.html

Endocrine system

http://www.sums.ac.ir/~moradij

Controls many body

functions

exerts control by

releasing special

chemical substances into

the blood called

hormones

Hormones affect other

endocrine glands or body

systems

http://www.sums.ac.ir/~moradij

Exocrine: glands

transport their

hormones to target

tissues via ducts.

Endocrine :glands

release hormones

directly into the

blood, which in turn

transports the

hormones to target

Endocrine System

A. Exocrine gland

Ducts

Lumen and

surfaces

B. Endocrine gland

Chemical

messengers

Blood stream

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http://www.sums.ac.ir/~moradij

Hormone + target =

change in cell

function

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Hormone + Receptor

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Hormones

Chemical

messenger

Secreted by

endocrine gland

Specific to target

Activate cellular

change

Of 4 different

chemical types

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Endocrine System and

Homeostasis

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Control of Endocrine Function

A. Positive

B. or Negative

Feedback

mechanisms

Self-regulating

system

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A. Positive Feedback

Not common

Classic example:

Action of

OXYTOCIN on

uterine muscle

during birth.

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B. Negative Feedback

Most common

control mechanism

Level of hormone in

blood or body’s

return to

homeostasis shuts

off loop at

hypothalamus and

pituitary

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Endocrine Glands

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http://www.sums.ac.ir/~moradij

Hypophys Gland

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Anterior Pituitary Hormones

HORMONE TARGET FUNCTION

Thyroid (TSH)

Stimulating

Thyroid gland TH synthesis &

release

Growth (GH) Many tissues growth

Adrenocortico-

Tropin (ACTH)

Adrenal cortex Cortisol release

(androgens)

Prolactin (Prl) Breast Milk production

Follicle (FSH) Gonads Egg/sperm prod.

Luteinizing (LH) Gonads Sex hormoneshttp://www.sums.ac.ir/~moradij

Neurosecretory Cells

Specialized neurons

Synthesize and

secrete hormones

Extend from

HYPOTHALAMUS

to POSTERIOR

PITUITARY

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Posterior Pituitary Hormones

Manufactured in Hypothalamus, released from Post. Pit.

Oxytocin

Target = smooth ms. Uterus and Breast

Function = labor and delivery, milk ejection,(pair bonding)

ADH (Vasopressin AVP)

Target = kidneys

Function = water Reabsorption

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What happens with excess GH?

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GH as Juvenile

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GH as an Adult

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Hypersecretion of GH

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GH = pituitary dwarfism

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Thyroid Gland

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http://www.sums.ac.ir/~moradij

لوب راست و چپ و بخش میانی

رشد، فعالیت فیزیکی، حالات روحی و تغییرات : تیروکسین

جنسی، درجه حرارت

http://www.sums.ac.ir/~moradij

Parathyroid GlandsSecretes parathyroid hormone

regulates plasma calcium (osteoclast activity)

regulates phosphate levels

Adrenal GlandAdrenal gland located atop kidney

Outer part = cortex

Secretes Cortisol (stress), Androgens,

Aldosterone (electrolytes)

Inner part = medulla

Secretes EPI & NEPI

(fight or flight)

SNS control

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Hypersecretion of Adrenal Cortex

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Cushing’s Syndrome?

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Pineal gland

ارتباط با مسیر بینایی: مغز میانی

رنگ پوست :اثر بر سایر غدد، ملاتونینhttp://www.sums.ac.ir/~moradij

http://www.sums.ac.ir/~moradij

PancreasLocated slightly behind the stomach

Insulin: reduces blood glucose

Facilitates glucose transport into the

cells

Promotes glycogenesis

Inhibits gluconeogensis

Glucagon: increases blood glucose

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Gonadstestes (testosterone) = sex

characteristics

muscle development and

maturity

ovaries (estrogen) = sex

characteristics

maturity and coordination

Breasts

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غدد عرق تغییر شکل یافته

نیپل، هاله، مجاری شیری

Breasts

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Other Secretions

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Other Secretions

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