for communicating controlling and coordinating the bodys work Endocrine System Control system that works along with the nervous system to regulate body functions and maintain homeostasis ID: 917147
Download Presentation The PPT/PDF document "Endocrine System The endocrine system is..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Endocrine System
The endocrine system is one of the body’s main systems
for
communicating, controlling and
coordinating
the body’s work
Slide2Endocrine System
Control
system
that works along with the nervous system to regulate body functions and maintain homeostasis.
Endocrine System
Nervous System
slower response (minutes to hrs.)
potentially long duration of effects (hours to days)
works via chemical signals (“hormones”) which are released through interstitial fluid into blood capillaries
affects multiple cells throughout the body that have specific hormone receptors (“target cells”) resulting in change of metabolic activities of cells (ex. affects protein synthesis)
quick response (milliseconds)
relatively short duration of effect
works via electrical impulses (action potentials) and direct release of chemicals (neurotransmitters) across interstitial fluid to adjacent cells
affects specific sets of cells (neuron, muscle, gland) resulting in specific responses (ex. muscle contraction or glandular
secretion)
Slide3Endocrine System Vocabulary
Endocrinology
– Science that deals with a group of ductless glands and the action of their secretions which are transported via the blood stream
Hormones - chemical messengers carried by the blood from endocrine glands to the cell upon which they act. (target cells)
The word “hormone” is derived from a Greek term that means to arouse to activity.
Endocrine glands vs. Exocrine glands
Exocrine glands
secrete their products through
ducts
that lead to an open space
Salivary glands
, Sweat glands, Gastric glands,
Sebaceous
gland
glands
Endocrine glands
secrete hormones directly into the
bloodstream , no ducts involved
Thyroid gland
, Pituitary
, Parathyroid, Pancreas,
Adrenals…
Slide4Endocrine gland
Slide5Overview of Endocrine System
Endocrine system includes all endocrine cells, tissues, and endocrine glands (organs) of the body
System of ductless glands that secrete hormones– chemical messengers/molecules
Circulate in bloodAct on target cells
Target cells respond to the hormones for which they have
receptors
E
ffects
are dependent on the programmed response of the target
cells
Hormones are just molecular triggers
Slide6Overview of Endocrine System
Some organs are primarily endocrine
organs/glands (pituitary
, thyroid, parathyroid, adrenal, pineal) Many different organs have some endocrine cells/tissues within their structure, but the organ’s primary function is not endocrine (ie: heart, kidney, digestive organs,
pancreas,
hypothalamus, gonads, thymus)
Slide7Slide8Classification of Hormones
Hormones classified
based on their chemical
structure
Steroid
Based
Non-Steroid
Based
Steroids,
lipid-like compounds derived from cholesterol
Lipid
-solubl
e can
pass through cell membrane
requires
intracellular receptors (
bind to receptors within the cell) and
can directly affect the structure or function of the cell, via affect on protein synthesis &/or energy production
Amino Acid Derivatives
Peptide hormones
Other: Prostaglandins
Local, or tissue, hormones
Derived from lipid molecules
Do not travel in the bloodstream
Target tissues are located close by
Produced by organs such as
Kidneys
Heart
Stomach
Uterus
Brain
Water
soluble
and
do not enter the cell
requires
membrane receptors
–(bind to receptors on cell membrane) triggering a cascade of biological activity
enzymes catalyzes a reaction that produced a second messenger molecule that
oversees additional intracellular changes that promotes a response of the target cell
Slide9Secretion, Distribution &
Effect
of Hormones
Hormones are released on demand – only when needed
Hormone release is primarily regulated by negative feedback mechanisms
changes in ECF (ISF/plasma) concentration/composition
changes in circulating levels of hormone itself or regulating hormones
neural stimuli
Hormones secreted by endocrine cells into interstitial fluid, and distributed through bloodstream
Only cells that posses receptors for that particular hormone can be affected
-“
target cell/target organ
”
Effect of hormones is on
the metabolic
activity of cells, via activation/inactivation of specific
genes, or affecting
protein synthesis
Slide10Secretion, Distribution &
Effect of Hormones
Slide11Mechanisms of hormone release
Humoral
:
substances other than hormones control the secretion of endocrine glands ( nutrient, ion level)
Neural
: nervous system stimulates the endocrine gland to release hormone
Hormonal
:
hormones
from one gland stimulate the release of hormones from another gland
Slide12Hypothalamus & Pituitary Gland
The
pituitary gland
, or
hypophysis
:
i
s an endocrine gland about
the size of a pea and weighing 0.5 g (0.02 oz.)
It
is a protrusion off the bottom of the hypothalamus
at
the base of the
brain
rests
in a small, bony cavity (
sella
turcica
)
of the
spheniod
bone at the base of the brain
is connected
to the hypothalamus small tube called the infundibular stem (Pituitary stalk). has two functional lobes : the anterior and posterior pituitarysecretes hormones that regulate homeostasis.
Slide13Hormones released from the Pituitary Gland
Slide14Pituitary Gland – Posterior lobe
Hormones: released hormones made by the hypothalamus
Oxytocin
Contractions uterus
“let down” reflex – milk ejection
Antidiuretic Hormone
Retention of water
Vasopressin effect , increase BP by constricting arterioles
Slide15Pituitary Gland – Anterior lobe
Growth Hormone
Stimulates cells to grow & divide
Fat broken down to use as energy
Maintain blood sugar homeostasis
Insulin-Like Growth Factor - 1
Bone growth
Protein synthesis
Liver and other tissues
Slide16Pituitary Gland – Anterior lobe
Prolactin (PRL)
Stimulates/maintains milk production
Unknown function in males
Slide17Pituitary Gland – Anterior lobe
Follicle-Stimulating Hormone (FSH) & Luteinizing
Hormone (LH
) also known as Interstitial Cell Stimulating Hormone (ICSH)
Regulate hormonal activities of gonads
Ovaries:
Estrogen
Uterine lining growth
Develop/maintain secondary sex characteristics
Progesterone
Uterine lining growth
Testes:
Androgens
(Testosterone)
Supports sperm and secondary sex characteristics
Ovary
Testicle
Gonadotropic Hormones
:
Slide18Pituitary Gland – Anterior lobe
Thyrotrophic hormone or Thyroid Stimulating Hormone (TSH)
Influences growth & activity of thyroid
Thyroxine
(T4)
Stimulates metabolism
Triiodothyronine
(T3)
Stimulates
metabolism
Calcitonin
Decrease calcium levels
Slide19Pituitary Gland –
Anterior
lobe
Adrenocorticotropic hormone (ACTH)
Regulates activity of adrenal cortex
Androgens
Glucocorticoids
Cortisone & cortisol
Increase blood glucose
Control inflammation
Decrease edema
Reduce pain
Mineralocorticoids/Aldosterone
Regulate water and electrolyte balance
Adrenal medulla
Epinephrine & Norepinephrine
Increase heart rate
Increase blood glucose
Increase BP
Increase metabolic rate
Long-term Stress Response
Short-term Stress Response
Slide20Hormones released from the Pituitary Gland
Slide21Pineal Gland/Pineal Body
Also known as the “third eye”
Found in roof of the third ventricle of the brain
MelatoninInvolved in rhythmic activities (day/night and seasonal)
Slide22Parathyroid gland
Tiny masses of glandular tissue found on posterior surfaces of thyroid gland
Parathyroid hormone (PTH) or
ParathormoneIncreases blood calcium levels
Stimulates osteoclasts to break down bone matrix to release calcium into the blood
Thyroid gland
Parathyroid gland
Slide23Thymus Gland
Posterior to sternum, superior to the heart
Large in infants and children, decreases in size throughout adulthood
Thymosin
Programs “T” cells (Lymphocytes – a type of white blood cell)
Plays role in immunity
Slide24Pancreas Islets (Islets of Langerhans)
Formerly known as Islets
of
Langerhans or islands of Langerhans, irregularly shaped patches of endocrine tissue located within the pancreas
Insulin
(released from beta cells)
Reduces blood glucose level
Increases ability of cells to transport glucose across cell membrane
Glucagon
(released from alpha
cells
)
Raises blood glucose level
Slide25Other Hormone P
roducing Tissue and Organs
Placenta
Temporary organ
Human Chorionic Gonadotropin
Stimulates production of estrogen and progesterone for maintenance of uterine lining
Slide26Other Hormone Producing Tissue and Organs
Stomach
Gastrin
Stimulates glands to release hydrochloric acid (HCl
)
Duodenum
Intestinal Gastrin
Inhibits
HCl
secretion
Secretin
Aids in functions related to digestion effecting pancreas, liver and stomach
Cholecystokinin (CCK)
Aids in functions related to digestion effecting pancreas,
gall bladder and duodenum
Slide27Other Hormone Producing Tissue and Organs
Kidneys
ErythroproteinEffects bone marrow stimulates red blood cell production
Vitamin D
3
(
Calcitriol
)
Aids in the active transport of dietary calcium across intestinal cell membrane
Slide28Other Hormone Producing Tissue and Organs
Heart
Atrial Natriuretic Peptide (ANP)
Affects kidney by decreasing sodium reabsorption and releasing renin
(
enzyme that aid in increasing BP)
Affects adrenal cortex decreasing secretion of aldosterone
Slide29Endocrine gland & Hormone review
A.
Name the gland.
Identify the hormone(s) released from gland.
Mechanism of
stimulus/Regulated by?
Slide30Endocrine gland & Hormone review
B.
Name the gland.
Identify the hormone(s) released form gland.
Mechanism of
stimulus/Regulated by?
Slide31Endocrine gland & Hormone review
C.
Name the gland.
Identify the hormone(s) released form gland.
Mechanism of stimulus/Regulated by?
Slide32Endocrine gland & Hormone review
D.
Name the gland.
Identify the hormone(s) released form gland.
Mechanism of stimulus/Regulated by?
Slide33Endocrine gland & Hormone review
E.
Name the gland
. Identify the hormone(s) released
from
gland.
Mechanism of
stimulus/Regulated by?
Slide34Endocrine gland & Hormone review
F.
Name the gland.
Identify the hormone(s) released form gland.
Mechanism of stimulus/Regulated by?
Slide35Endocrine gland & Hormone review
G
.
Name the gland.Identify the hormone(s) released form gland.
Mechanism of stimulus?
Slide36Endocrine gland & Hormone review
H
.
Name the gland.Identify the hormone(s) released
from
gland.
Mechanism of stimulus/Regulated by?
Slide37Endocrine Review
Matching I
1. _____ Stimulate development of the follicle in the ovaries
2. _____ Stimulates the kidney to reabsorb water from urine
3. _____ Stimulates the thyroid gland
4. _____ Stimulates the adrenal cortex
5. _____ Promotes protein synthesis necessary for growth
FSH
GH
ACTH
TSH
ADH
Slide38Endocrine Review
Matching II
1. _____ Increases blood glucose levels
2. _____ Decreases blood calcium levels3. _____Regulates body metabolism
4. _____ Increases blood calcium levels
5. _____Regulate electrolyte balance
Aldosterone
Glucagon
Thyroxine
Calcitonin
Parathyroid hormone
Slide39Endocrine Review
Review chart in text pp. 270-271 to review major glands, hormone(s) released, hormone(s) chemical
class,
their actions and means of regulation.Continue on to learn about Factors that Affect Endocrine Function
Slide40Factors that Affect Endocrine Function
Everyone's body undergoes changes, some natural and some not, that can affect the way the endocrine system works. Some of the factors that affect endocrine organs
include:
aging illness s
tress
the environment
and
genetics
.
Slide41Aging
D
espite
age-related changes, the endocrine system functions well in most older people. However, some changes do occur because of normal damage to cells during the aging process and genetically programmed cellular changes. These changes may alter the following
:
hormone production and secretion
hormone metabolism (how quickly excess hormones are broken down and leave the body, for example, through urination)
hormone levels circulating in blood
biological activities
target cell or target tissue response to hormones
rhythms in the body, such as the menstrual cycle
Slide42Aging
For example, increasing age is thought to be related to the development of Type II diabetes. With aging, the target cell response time becomes slower, especially in people who might be at risk for this disorder.
The signs and symptoms of endocrine system diseases affect many body systems. In elderly persons, they are frequently subtle and may be harder to detect than in younger persons. At times, these signs are incorrectly linked with other causes, such as the changes of normal aging, other medical disorders or conditions, or drug
therapy.
The
aging process affects nearly every gland. For example, the hypothalamus is responsible for releasing hormones that stimulate the pituitary gland. During aging, there is either impaired secretion of some hypothalamic hormones or impaired pituitary response. These changes appear to influence the endocrine system's ability to respond to the body's internal environment. As a result, the body cannot respond as well either to internal or external stresses
Slide43Aging
With increasing age, the pituitary gland can become smaller and more fibrous and may not work as well. For example, production of growth hormone may decrease. This may lead to a hormone imbalance that causes problems such as decreased lean muscle, decreased heart function, and osteoporosis.
Aging can affect a woman's ovaries. These organs eventually exhibit the most common endocrine change related to aging: menopause. In menopause, the ovaries stop responding to follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. Ovarian hormone production of estrogen and progesterone slows down and then stops. Eventually a woman stops having her periods altogether
Slide44Illness
Illness
may affect endocrine system function in several ways. Acute or chronic conditions may change endocrine functions
.Chronic/Acute ConditionsHormones are cleared from blood during their circulation to the target tissues. The liver and kidneys are primarily responsible for clearing hormones. Several clearance processes become altered or slowed in individuals who have chronic heart, liver, or kidney disorders.
Acute physical or mental stressors can trigger a preprogrammed stress response. The stress response is complex and can influence heart, kidney, liver, and endocrine system function.
Slide45Endocrine Pathologies
Endocrine
pathologies can result from the following
:
congenital (birth) or genetic defects
surgery
traumatic injuries
cancerous and non-cancerous tumors
infection
autoimmune destruction (the immune system turns against the body's own organs and causes damage
)
In general, endocrine pathologies create a hormone imbalance typified by either
hyposecretion
(underproduction) or
hypersecretion
(overproduction) of hormones. The underlying problem may be the endocrine gland itself or a source outside the gland.
Slide46Stress
Many
factors can start the stress response, but physical stressors are most important. In order for the body to respond to, and cope with, physical stress, the adrenal glands make more cortisol. If the adrenal glands do not respond, this can be a life-threatening problem. Some medically important factors causing a stress response are as follows
:
trauma (severe injury) of any type
severe illness or infection
intense heat or cold
surgical procedures
serious diseases
allergic
reactions
Other types of stress include emotional, social, or economic, but these do not require the body to produce high levels of cortisol in order to survive the stress.
Slide47External Factors
An
environmental endocrine disruptor (EED) is a substance outside of the body that may cause adverse effects to normal function of the endocrine system. Some EEDs mimic natural hormone binding at the target cell receptor. These substances start the same processes between body cells that the natural hormone would start. EEDs of this type are referred to as hormone agonists.
Other EEDs block cellular events associated with hormone binding. These EEDs are called hormone antagonists. Still other EEDs can directly interfere with the production, storage, release, transport, clearance, binding, or elimination of endogenous hormones in the body. This can greatly affect the function of certain body systems.
Slide48External Factors
There are currently over 84,000 commercial synthetic chemical substances in use around the world. At least 30,000 have been introduced into the U.S. environment since 1979. We do not know the extent to which they can interfere with the endocrine system and cause endocrine system diseases. Based on our knowledge of the effects of certain synthetic chemicals, such as DDT, diethylstilbestrol and PCBs, and the increasing evidence that reproductive function in wildlife and humans is changing, scientists are now examining a broad range of chemical effects
.
EEDs
can affect people and animals in many ways
:
disrupted sexual development
decreased fertility
birth defects
decreased hatching in animals
reduced immune response
neurological and behavioral changes, including reduced stress tolerance
Slide49Genetics
Portions
of your endocrine system can be affected by genes. Genes are units of hereditary information passed from parent to child. Genes contain the instructions for the production of proteins, which are some of the essential components of the body. Genes are contained in chromosomes. The normal number of chromosomes is 46 (23 pairs).
Sometimes extra, missing, altered, or damaged chromosomes can result in diseases or conditions that affect hormone production or function. The 23rd pair, for example, is the sex chromosome pair. The mother and father each contribute a sex chromosome to the child. Girls have two X chromosomes (one from the mother and one from the father), while boys have one X (from mother) and one Y (from father) chromosome. Sometimes, however, a chromosome or piece of a chromosome may be missing. In Turner syndrome, only one normal X chromosome is present and this can cause poor growth. In another example, a child with
Prader-Willi
syndrome (PWS) may be missing all or part of chromosome 15, which also affects growth, metabolism, and puberty.
Slide50Genetics
Your genes also may place you at increased risk for certain diseases, such as breast cancer. Taking estrogen can cause breast tissue to grow faster. Cancer usually appears in fast-growing tissue. This is one of the ways that scientists believe that taking estrogen for symptoms of menopause may be related to developing breast cancer. Another idea is that breast tissue breaks down estrogen into chemicals that can bind to DNA (genetic material) and damage it. Damage to DNA is a common cause of cancer. At this time, it is not known exactly why estrogen might cause breast cancer or what role it does play in breast cancer growth.
Slide51Cycles of Hormone Release
Time
appears to affect the release of certain types of hormones. Some hormones have a typical cycling pattern of release. This pattern often fits with daily body rhythms or the sleep-wake cycle
.
Cortisol builds up early in the day, decreases toward evening, rises again toward the end of sleep, and peaks during the morning hours.
Thyroid-stimulating hormone (TSH) peaks during sleep and reaches its low point three hours after an individual awakens.
Levels of growth hormone (GH) are high 90 minutes after sleep begins. GH typically increases during the first 2 hours of deep sleep. It also increases if a person is hypoglycemic (low blood sugar), starving, exercising, excited or is a victim of severe injury.
There is a very definite rise-and-fall pattern to both estrogen and progesterone activity during a woman's menstrual cycle, which lasts an average of 28 days.
Slide52Endocrine disorders: Classification
of endocrine system disorders
The broad classification of endocrine system diseases is based on the hormonal secretions.
Hypersecretion by endocrine glands (Excessive secretion of hormones)Hyposecretion by endocrine glands (Insufficient secretion of hormones)
Cancer or tumors in the endocrine gland
Slide53In summary
The endocrine system includes all of the glands of the body and the hormones produced by those glands. The glands are controlled directly by stimulation from the nervous system as well as by chemical receptors in the blood and hormones produced by other glands. By regulating the functions of organs in the body, these glands help to maintain the body’s homeostasis.