Regulation The Endocrine System Regulation: The Endocrine System.
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Regulation Regulation: The The Endocrine System Endocrine System
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Transcript of Regulation The Endocrine System Regulation: The Endocrine System.
RegulationRegulation: The Endocrine SystemThe Endocrine System
Endocrine System FunctionEndocrine System Function
Coordinate body functions using chemical messages (Hormones)
Works with the nervous system to provide homeostasis
Slower to respond than Nervous System
Effect lasts longer than Nervous System
Endocrine SystemEndocrine System
Example: Glucagon from the pancreas (hormone) and the liver hepatocytes (targets)
Endocrine glands:•Secrete hormones into bloodstream•Ductless
Target Cells:Cells with appropriate receptors that respond to the hormone
ENDOCRINE ENDOCRINE SYSTEM: SYSTEM:
Major Major Organs Organs
ENDOCRINE SYSTEM: ENDOCRINE SYSTEM: Major OrgansMajor Organs
• Hypothalamus and Pituitary gland• Hypothalamus (part of CNS)
– controls the hormonal secretions of the pituitary gland.
• Pituitary gland – The Master Gland– secretes hormones that regulate other endocrine glands. – For example:
Follicle-Stimulating Hormone (FSH): Causes reproductive organs (ovaries, testes) to produce gametes & hormones.
Hypothalamus Hypothalamus and Pituitaryand Pituitary
ENDOCRINE SYSTEM: ENDOCRINE SYSTEM: Major OrgansMajor Organs
• Adrenal gland: Epinephrine [formerly adrenalin] Mobilizes body for action:
– increases heart rate, blood pressure, and breathing rate
• Pancreas: Insulin - Causes cells to take up glucose from blood
Glucagon – Causes liver to release glucose to blood
ENDOCRINE SYSTEM: ENDOCRINE SYSTEM: Major OrgansMajor Organs
Thyroid:
Thyroxin
Increases overall metabolic rates
Needs iodine to make thyroxin
ENDOCRINE SYSTEM: ENDOCRINE SYSTEM: Major OrgansMajor Organs
Gonads (Sex Cell Organs)Ovary • Estrogen - Promotes development of female
sex organs & secondary sexual characteristics.• Progesterone -
causes uterus to thicken & become vascularized [once every menstrual cycle]
Testis• Testosterone - Promotes development of male
sex organs & secondary sexual characteristics.
Endocrine System ControlEndocrine System Control Feedback loop systems
The level of a hormone controls its release
Example:
Hypothalamus tells pituitary to send out TSH when thyroxin levels are low
TSH tells the thyroid to release thyroxin
High levels of thyroxin reduces the amount of TSH released
Control of Control of Blood SugarBlood Sugar
After a meal, blood glucose levels are high
Pancreas secretes insulin to lower it
Glucose is stored as glycogen in the liver and muscles
Before a meal, blood glucose levels are low
Pancreas secretes glucagon to raise it
Glucose is released from the liver
calcitonin
Bones take up Ca2+
from blood.Thyroid glandsecretes calcitonininto blood.
Regulation Regulation of Blood of Blood Calcium Calcium
LevelLevel
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Homeostasisnormal blood Ca2+
high blood Ca 2+
low blood Ca 2+
Kidneys reabsorb Ca2+
from kidneytubules.
Intestines absorb Ca2+
from digestivetract.
activatedvitamin D
Bones release Ca2+
into blood.
parathyroid hormone (PTH)
Parathyroid glands release PTHinto blood.
Blood Ca2+ rises.
Blood Ca2+ lowers.
Label the Label the Glands of Glands of
the the Endocrine Endocrine
SystemSystem
Pituitary
Thyroid
Parathyroid
AdrenalPancreas
Ovary
Testes
