the endocrine system -...
TRANSCRIPT
Essentials of Human Anatomy & Physiology
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slides 9.1 – 9.22
Seventh Edition
Elaine N. Marieb
Chapter 9
The Endocrine System
Lecture Slides in PowerPoint by Jerry L. Cook
I. Characteristics
Slide 9.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Second messenger system
Uses chemical messages (hormones) that are released into the blood
Blood transfers hormones to target sites where they regulate the activity of other cells
II. Hormone Processes Reproduction
Growth and development
Mobilization of body defenses
Maintenance of homeostasis
Regulation of metabolism
III. Mechanisms of Hormone Action
Slide 9.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Hormones affect only certain tissues or organs (target cells or organs) that have a specific protein receptors
Hormone binding influences the working of the cells
IV. Effects Caused by Hormones
Slide 9.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Changes in plasma membrane permeability or electrical state
Synthesis of proteins, such as enzymes
Activation or inactivation of enzymes
Stimulation of mitosis
V. Control of Hormone Release
Slide 9.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Hormone levels in the blood are maintained by negative feedback
A stimulus or low hormone levels in the blood triggers the release of more hormone
Hormone release stops once an appropriate level in the blood is reached
The Chemistry of Hormones
Slide 9.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Steroids – made from cholesterol
Steroid Hormone Action
Slide 9.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Diffuse through the membrane of target cells
Enter the nucleus
Bind to a specific protein within the nucleus
Bind to specific sites on the cell’s DNA
Activate genes that result in synthesis of new proteins
The Chemistry of Hormones
Slide 9.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Non-Steroid Hormones made from
Amino acid-based hormones
Prostaglandins – made from highly active lipids
Nonsteroid Hormone Action
Slide 9.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Hormone does not enter the cell but binds to a membrane receptor
Sets off a series of reactions that activates an enzyme
Catalyzes a reaction that produces a second messenger molecule
Oversees additional intracellular changes to promote a specific response
Hormonal Stimuli of Endocrine Glands
Slide 9.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Endocrine glands are activated by other hormones
Figure 9.2a
Humoral Stimuli of Endocrine
Glands
Slide 9.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.2b
Changing blood levels of certain ions stimulate hormone release
Neural Stimuli of Endocrine Glands
Slide 9.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Nerve impulses stimulate hormone release
Most are under control of the sympathetic nervous system
Figure 9.2c
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Pituitary Gland – Characteristics
Slide 9.15 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Hangs by a stalk from the hypothalamus
Has two functional lobes
Anterior pituitary – glandular tissue
Posterior pituitary – nervous tissue
Characteristics of all anterior
pituitary hormones
Slide 9.16 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Proteins (or peptides)
Act through second-messenger systems
Regulated by hormonal stimuli, mostly negative feedback
Hormones of the Anterior Pituitary
Slide 9.17 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.4
Growth Hormone (GH)
Slide 9.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
General metabolic hormone
Effects growth of skeletal muscles and long bones
Causes amino acids to be built into proteins
Causes fats to be broken down for a source of energy
Prolactin (PRL)
Slide 9.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Stimulates and maintains milk production following childbirth
Adrenocorticotropic hormone (ACTH)
Slide 9.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Regulates endocrine activity of the adrenal cortex
Thyroid-stimulating hormone (TSH)
Slide 9.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Influences growth and activity of the thyroid
Gonadotropic hormones
Slide 9.20a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Follicle-stimulating hormone (FSH)
Stimulates follicle development in ovaries
Stimulates sperm development in testes
Gonadotropic hormones (continued)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Luteinizing hormone (LH)
Triggers ovulation
Causes ruptured follicle to become the corpus luteum
Stimulates testosterone production in males
Referred to as interstitial cell-stimulating hormone (ICSH)
Pituitary - Hypothalamus Relationship
Slide 9.21 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Release of hormones is controlled by releasing and inhibiting hormones produced by the hypothalamus
Hypothalamus produces two hormones that are transported to the posterior pituitary
Characteristics of Posterior Pituitary
Slide 9.21 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Not strictly an endocrine gland, but does release hormones
Hormones of the Posterior Pituitary
Slide 9.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Oxytocin
Stimulates contractions of the uterus during labor
Causes milk ejection (let-down)
Hormones of the Posterior Pituitary
Slide 9.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Antidiuretic hormone (ADH)
Can inhibit urine production
In large amounts, causes vasoconstriction leading to increased blood pressure (vasopressin)
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Thyroid Gland
Slide 9.23a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Found at the base of the throat
Consists of two lobes and a connecting isthmus
Thyroid Gland
Slide 9.23b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.6
Thyroid Hormone
Slide 9.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Major metabolic hormone
Composed of two active iodine-containing hormones Thyroxine (T4) and Triiodothyronine (T3)
Calcitonin
Slide 9.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Decreases blood calcium levels by causing its deposition on bone
Antagonistic to parathyroid hormone
Figure 9.9
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Parathyroid Glands
Slide 9.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Tiny masses on the posterior of the thyroid
Parathyroid Glands
Slide 9.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
parathyroid hormone
Stimulate osteoclasts to remove calcium from bone
Stimulate the kidneys and intestine to absorb more calcium
Raise calcium levels in the blood
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Adrenal Cortex
Slide 9.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Makes hormones to prepare the body to deal with long-term stress response
Hormones of the Adrenal Cortex
Slide 9.28a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Mineralocorticoids (mainly aldosterone)
Regulate mineral content in blood, water, and electrolyte balance
Target organ is the kidney
Hormones of the Adrenal Cortex
Slide 9.28b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.10
Hormones of the Adrenal Cortex
Slide 9.29a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Glucocorticoids (including cortisone and cortisol)
Promote normal cell metabolism
Help resist long-term stressors
Released in response to increased blood levels of ACTH
Hormones of the Adrenal Cortex
Slide 9.29b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Sex hormones
Androgens (male) and some estrogen (female)
Adrenal Medulla
Slide 9.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Makes hormones to prepare the body to deal with short-term stress
Hormones of the Adrenal Medulla
Slide 9.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Epinephrine & Norepinephrine
Increase blood glucose
Increase rate of metabolism
Constrict certain blood vessels
Roles of the Hypothalamus and Adrenal
Glands in the Stress Response
Slide 9.31 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.12
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Pancreatic Islets
Slide 9.32a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
The pancreas is a mixed gland that produces hormones that have an antagonistic effect to maintain blood sugar homeostasis
Pancreatic Islets
Slide 9.32a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Insulin – allows glucose to cross plasma membranes into cells
Glucagon – allows glucose to enter the blood
Pancreatic Islets
Slide 9.32b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.13
Pancreatic Hormones and Blood Sugar
Slide 9.33 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.14
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Pineal Gland
Slide 9.34 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Found on the third
ventricle of the
brain
Secretes melatonin
Helps establish the
body’s wake and
sleep cycles
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Thymus
Slide 9.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Located posterior to the sternum
Largest in infants and children
Thymus
Slide 9.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Produces thymosin
Matures some types of white blood cells
Important in developing the immune system
Location of Major Endrocrine Organs
Slide 9.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 9.3
Hormones of the Ovaries
Slide 9.36 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Estrogens
Stimulates the development of secondary female characteristics
Matures female reproductive organs
Helps prepare the uterus to receive a fertilized egg
Helps maintain pregnancy
Prepares the breasts to produce milk
Hormones of the Ovaries
Slide 9.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Progesterone
Produced by the corpus luteum
Acts with estrogen to bring about the menstrual cycle
Helps in the implantation of an embryo in the uterus