Download presentation
Presentation is loading. Please wait.
1
Endocrine System Chapter 9
2
Overview of Hormones The endocrine and nervous systems often work together to bring about homeostasis. The blood stream transports hormones throughout the body.
3
Overview of Hormones Each hormone acts on a certain type of tissue called its target tissue. Organs, tissues, or cells lacking the specific receptor do not respond to its stimulating effects.
4
Negative Feedback Loop
A decrease in function in response to a stimulus The system controls how much product it makes by shutting down manufacturing when levels of output or the amount of accumulated product gets too high Example # 1: the regulation of the blood glucose level in the body Example # 2: regulation of body temperature
5
Negative Feedback Loop
6
Positive Feedback Loop
An increase in function in response to a stimulus “A” produces more of “B” which in turn produces more of “A” Only a few positive feedback loops occur in the human endocrine system. Example: the process of birthing a child
7
Positive Feedback Loop
8
Glands
9
Glands Exocrine glands – secretions released into ducts opening onto an epithelial surface Endocrine glands – ductless organs that secrete their molecules directly into the bloodstream
10
Glands Endocrine glands are activated by other hormones
11
Hypothalamus Controls the pituitary gland
Receives information from the nervous system
12
Pituitary Location: Inferior to the hypothalamus
Known as the master gland
13
I. Anterior Pituitary 1. Growth hormone (GH) General metabolic hormone
Major effects are directed to growth of skeletal muscles and long bones
14
I. Anterior Pituitary 2. Prolactin (PRL)
Stimulates and maintains milk production following childbirth Function in males is unknown
15
I. Anterior Pituitary 3. Adrenocorticotropic hormone (ACTH)
Regulates endocrine activity of the adrenal cortex which makes a hormone called cortisol (helps the body manage stress)
16
I. Anterior Pituitary 4. Thyroid-stimulating hormone (TSH)
Produces the hormone thyroxine Regulates the rate of metabolism
17
I. Anterior Pituitary Gonadotropic hormones – Regulate hormonal activity of the gonads 5. Follicle-stimulating hormone (FSH) Stimulates follicle development in ovaries Stimulates sperm development in testes
18
I. Anterior Pituitary Gonadotropic hormones – Regulate hormonal activity of the gonads 6. Luteinizing hormone (LH) Triggers ovulation Prepares uterus for fertilized egg Stimulates testosterone production in males
19
II. Posterior Pituitary
1. Oxytocin Stimulates contractions of the uterus during labor Causes milk ejection
20
II. Posterior Pituitary
2. Antidiuretic hormone (ADH) Can inhibit urine production In large amounts, causes vasoconstriction leading to increased blood pressure
22
Posterior Pituitary Anterior Pituitary
24
Mnemonic Device for anterior and posterior pituitary gland
Anterior pituitary FLAT PIG 1. FSH 2. LH 3. ACTH 4. TSH 5. Prolactin (Ignore) 6. Growth Hormone Posterior pituitary Audio Osmosis = AO 1. ADH 2. Oxytocin
25
Anterior Pituitary Gland Chart
Mnemonic Device (Letter) Hormone Targeted Area Produces F FSH Ovaries and Testes Sperm and egg L LH Ovulation and testosterone A ACTH Adrenal Gland Cortisol T TSH Thyroid Thryoxine P Prolactin Breast Milk I Ignore - G GH Muscles and bones Growth of muscles and bones
26
Posterior Pituitary Gland Chart
Mnemonic Device (Letter) Hormone Targeted Area Produces A ADH Kidneys Inhibit urine production O Oxytocin Uterus and breast Uterine contraction and milk letdown
27
Pineal Location: Between the left and right hemispheres (thalamus region) Hormone: Melatonin Function: maintains the body’s circadian cycle (a daily cycle of activity observed in many living organisms)
28
Thyroid Located in the neck in front of the trachea
Thyroid gland releases the hormone thyroxine. Function: regulates the rate of metabolism
29
Parathyroid Location: embedded in back of thyroid gland
Hormone: Parathormone Function: Controls the metabolism of calcium
30
Thymus Located posterior to the sternum
Helps develop the immune system in infants Helps lymphocytes to mature
31
Adrenal Gland Location: on top of kidney Hormone: Adrenaline
Function: Raises blood sugar level and increases heart beat and breathing rates
32
Islets of Langerhans Location: Pancreas Hormones: Insulin
Produced by beta cells Function: Stimulates glucose uptake by cells
33
Islets of Langerhans Location: Pancreas Hormone: Glucagon
Produced by alpha cells Function: Promote conversion (change of glycogen to glucose)
34
body cells take up sugar from blood
Endocrine System Control Feedback Regulation of Blood Sugar insulin body cells take up sugar from blood liver stores sugar reduces appetite pancreas liver high blood sugar level (90mg/100ml) low liver releases sugar triggers hunger pancreas liver glucagon
35
Ovary Hormones: estrogen and progesterone Functions:
Estrogen helps develop secondary characteristics in females Progesterone prepares the uterus for the fertilized ovum and maintains pregnancy
36
Testes The testes secrete “male sex hormones” called androgens.
Testosterone is an androgen that develops the secondary characteristics in men.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.