Title: Chemical Signals in Animals
1Chapter 45
- Chemical Signals in Animals
2Basic info. on endocrine system
- Involves hormones-to excite secreted into
blood. - Cells that respond to hormones are called target
cells. May be distant from origin. - Endocrine system-made of ductless
glands-secrete into bloodstream.
(Exocrine-secrete to surface)
3- Relationship to nervous system endocrine system
contains neurosecretory cells. Ex.
Epinephrine/Adrenaline-secreted by adrenal gland
affects responses (fight-or flight) and acts as a
neurotransmitter. - Both controlled by feedback
4Hormones and invertebrates
- Hormones control reproduction molting water
balance, etc. - Ex. Ecdysone-produced by arthropods to trigger
molting. - Brain hormone-increase in this production
stimulates gland to produce ecdysone. - Juvenile hormone-maintains insect in larval stage
5Signal transduction
- Hormones usually attach to protein receptor of
plasma membrane. - May initiate response of substance in cytoplasm
or nucleus. - Ex. Human growth hormone. Causes bone cells to
produce secretion.
6- Hormone may enter cell to cause signal
- Ex. Steroid hormones-enter because they are
lipids and can cross cell membrane. - Bind to intracellular receptors that behave as
transcription factors-directly effect mRNA
production from DNA.
7Hormones may have affect on one tissue or
many. Ex. Sex hormones-affect gender
characteristics. Tropic hormones-those whose
target cells are part of another endocrine gland.
8Pituitary Gland
- Located at base of brain once referred to as
master gland. - Produces tropic hormones-ones that have an effect
on another endocrine gland.
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10- Hypothalamus receives brain signals which in turn
stimulate pituitary gland. - Makes releasing hormones to turn on and
inhibiting hormones to turn off pituitary
secretions.
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12ADH/vasopressin
- Antidiuretic hormone (ADH)-causes reabsorption of
water by kidneys. - Released if osmolarity of blood increases.
(solute concentration). - As dilute blood reaches brain, shuts down release
of ADH.
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14Growth hormone-stimulates bone cells
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16Pineal gland
- Secretes melatonin.
- Melatonin regulates functions based on light
intensity. - Seasonal depression-high melatonin level due to
low light intensity in winter.
17Parathyroid
- Releases PTH-raises blood Calcium level.
- Calcium comes from bone-released by
osteoclasts-bone destroying cells. - PTH also stimulates inactive vitamin D (from food
or made by skin when absorbing sunlight) to
become active. - Vitamin D helps in calcium absorbance from food.
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20Thyroid gland
- Calcitonin-lowers Ca ion levels in blood.
- Thyroxin and triiodothyronine
- Both contain iodine
- Both secreted but most converted to
triiodothyronine by target cells. - Secretions controlled by TSH of
hypothalamus/pituitary. - Involved in overall metabolism rate.
21Pancreas
- Islets of Langerhans-cells that secrete two
hormones. - Alpha cells-secrete glucagon
- Beta cells secrete insulin.
- Only brain cells can take up glucose without
insulin. - Glucagon breaks down glycogen in the liver.
22Diabetes-refers to excess urine.
- Diabetes mellitus-insufficient insulin OR loss of
response to insulin. - Kidneys secrete glucose, raises osmolarity which
causes thirst. - Fat used as fuel-forms acids which change blood
pH. - Type I-insulin dependent-autoimmune-childhood.
- Type II-non-insulin dependent-deficiency of
insulin or response to. Can be managed by diet.
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24Adrenal gland
- Made of medulla and cortex.
- Medulla secretes epinephrine and norepinephrine.
- Secreted due to stress.
25- Epinephrine increases heart rate dilates
bronchiole tubes constricts some blood vessels
while dilating others. Why might this be
important? - Norepinephrine maintains blood pressure and acts
as a neurotransmitter.
26- Adrenal Cortex
- Stimulated by ACTH from pituitary
- Produce corticosteroids-two types-glucocorticoids
and mineralocorticoids. - Glucocorticoids-involved in glucose metabolism
from proteins - Mineralocorticoids-ex. Aldosterone-involved in
reabsorption of sodium ions and water by kidney.
- Released as response to stress.
27- Gonadal hormones
- Androgens-ex. Testosterone (also produced by
adrenal cortex) - Estrogens
- Progesterone-important to maintaining pregnancy.
28Negative feedback
Secretion of TSH causes increase in thyroxin
production Normal thyroxin tells pituitary to
shut down production of TSH.
29Positive Feedback Mechanism
- Fewer examples than negative feedback.
- One response causes a continued and increased
response - Ex. Childbirth-oxytocin-produced by pituitary
gland-causes contractions of uterus. Causes more
oxytocin to be released causing more
contractions. - What happens when labor is induced?
30Diabetes Insipidus
31- Types of Diabetes Insipidus
- Central DI
- Gestational DI
- Nephrogenic DI
- It is a diabetes in which water is reabsorbed by
the kidneys, instead of going into the blood - It can be caused by kidney damage or pregnancy,
but is most commonly caused by a deficiency of ADH
32- ADH (antidiuretic hormone) is a hormone created
by the pituitary gland - It then goes to the kidney, where it regulates
water absorption - A diuretic increases urination levels, so
naturally an ADH decreases it - In DI, through various reasons, the kidneys dont
have enough ADH or they cannot use it. - One common treatment is the use of the hormone
vasopressin, another antidiuretic hormone
33HYPERTENSION as Related to Endocrine System
- Causes
- Too much aldosterone
- Pituitary gland
- Growths
- Metabolic syndrome
- Other diseases
- Endocrine system cause Hypertension?
- Hormones
- Symptoms
- High blood pressure
- Increased blood pressure
- Headache
- Fatigue
- Shortness of breath
- Dizziness
34HYPERTENSION as Related to Endocrine System
- Hypertension increases risk of
- Heart attack
- Stroke
- Kidney disease
- Death
- Primary or Secondary?
- Secondary Hypertension
- Pituitary and Adrenal glands?
- excess hormone production
- dysfunction
- Cure
- Surgery to remove tumor
- Surgery to remove growths
- Diet changes and medicine to lower blood pressure
35Acromegaly
- Gland Pituitary Gland
- Hormone Excess of hGH produced after puberty.
- Causes Tumors on Pituitary Gland
36Acromegaly
- Symtoms Enlarged hands and feet, may change
facial features (more pronounced jaw, brow, nose
and lips). - Treatments Lower levels of hGH, Remove tumors,
drug and radiation therapies.
37Hyperparathyroidism
- Involves the parathyroid glands
- Causes a secretion of excess parathyroid
hormone (PTH)
- Symptoms (caused by high levels of calcium)
- -Joint pain
- -Weakened bones
- -Nausea, vomiting, constipation
- -Lack of an appetite
- -Kidney stones
- -Excessive thirst or urination
- -Memory loss, anxiety, fatigue
By Josh Smith
38- Diagnosis occurs after finding high levels of
calcium and low levels of phosphorus in the blood
Treatments -Surgery to remove the enlarged
gland(s) -Taking calcimimetics a drug that
stops the secretion of PTH -Drinking water and
exercise (for mild cases) -Eating calcium rich
foods and avoiding alcohol, soda, and coffee
(For improving the symptoms)
Informational Sites -http//endocrine.niddk.nih.g
ov/pubs/hyper/hyper.htmsymptoms -http//www.umm.e
du/altmed/articles/hyperparathyroidism-000086.htm
39Hypoparathyroidism
- Reduced parathyroid hormone production due to a
damage to the parathyroid glands - Muscle spasms, cramping, dry skin and hair due to
low calcium levels - Short term treatment - IV Calcium
- Long term - Vitamin D3 and Calcium
Supplements
40Type I diabetes mellitus
- It lacks of an endocrine gland
- The pancreas produce insufficient insulin
- Insulin is a hormone that is needed to convert
sugar (glucose), starches and other food into
energy needed for daily life. - Frequent urination
- Unusual thirst
- Extreme hunger
- Unusual weight loss
- Extreme fatigue and Irritability
41Type I diabetes mellitus
- Treatment involves injecting insulin under the
skin for it to get absorbed into the blood stream
where it can then access all the cells of the
body that require it. Shots are the most widely
used method. - http//www.youtube.com/watch?vQWJJ3M3xss4
- Universal blue circle symbol for diabetes
42Hypoglycemia
- An abnormally low level of sugar in the blood.
- Over secretion of insulin by the pancreas in
response to a rapid rise in blood sugar or
glucose. - The blood sugar plummets below the level
necessary to maintain well-being.
43Graves Disease
44Graves Disease
- Graves' disease is the most common form of
hyperthyroidism, occurring when the immune system
mistakenly attacks the thyroid gland and causes
it to overproduce the hormone thyroxine. This
higher thyroxine level can greatly increase the
body's metabolic rate. This can cause anything
from a change in mood to a change in physical
appearance.
45Symptoms/Treatments
- Anxiety, Irritability, Difficulty sleeping,
Fatigue, A rapid or irregular heartbeat, A fine
tremor of your hands or fingers, An increase in
perspiration, Sensitivity to heat Weight loss,
despite normal food intake, Brittle hair,
Enlargement of your thyroid gland (goiter),
Change in menstrual cycles, Frequent bowel
movements - Antithyroid drugs, radioiodine therapy and
surgery to remove the thyroid gland are effective
treatments for Graves' disease. Subtotal
thyroidectomy surgery, an operation that removes
the majority of the gland so that the thyroid
does not overproduce thyroid hormones is also a
treatment option.
46Myxedema
47What causes Myxedema
- Hypothyroidism this condition can be caused by a
lack of thyroid hormone(EP, produce thyroxin). - Goiter not enough iodine
- Hashimotos thyroiditis autoimmune disease
attacks the thyroid gland.
48Symptoms and Treatments
- Skin gets thick and coarse(rough)
- Change shape of face
- Slow speech
- Mental dullness
- Treatments making sure a person has enough
thyroxin( take a pill with thyroxin or iodine)
49Goiter
Thyroid Gland
Endocrine gland involved
Goiter- enlargement of the thyroid gland
Primary function of thyroid gland
Concentrate iodine from the blood to form thyroid
hormones
Hypothalamus senses low level of thyroid hormone
The shortage of thyroid hormones
Caused by iodine deficiency (most common cause)
Send thyroid stimulating hormone (TSH) to thyroid
Stimulates and enlarge the thyroid gland to
produce thyroid hormone
Goiter
50Sandy Chen
http//www.thyroid.org/index.html
American thyroid association
51Cushings Disease
- Exogenous Cause (from outside the body)
-Taking high levels of steroid hormones called
glucocorticoids
--for organ transplant or inflammatory disease
Endogenous Cause (from within the body)
Body produces too much cortisol hormone
Pituitary Cushings- pituitary gland tumor
secretes excess cortisol
Adrenal Cushings- adrenal gland tumor secretes
excess cortisol
Ectopic Cushings- (tumor outside pituitary)
adrenal system secretes cortisol
52Symptoms
- -Upper body obesity
- -rounded face
- -fatigue
- -high blood pressure
- -depression
- -fragile/bruised skin
Treatment
Exogenous Cushings - reduce medication that
produces symptons
Pituitary/Adrenal - remove tumor with surgery,
radiation, or drug therapy
Ectopic - cancer treatment, e.g, surgery,
radiation, chemotherapy
53ADDISONS DISEASE
Chelsie Bivens
- Due to adrenal insufficiency (Adrenal glands are
located just above the kidneys.) - Addisons disease occurs from damaged adrenal
glands which cannot produce enough of the hormone
cortisol and the hormone aldosterone.
54ADDISONS DISEASE CONTINUED
- Symptoms include
- Sudden penetrating pain in the lower back,
abdomen, or legs - Severe vomiting and diarrhea
- Dehydration
- Low blood pressure
- Loss of consciousness
- Treatment includes
- Cortisol is substituted with a synthetic
glucocorticoid such as hydrocortisone or
prednisone. If aldosterone is also lacking, it
is replaced with doses of a mineralocorticoid.
These are both steroids which would be in
shortage due to adrenal insufficiency.
55Seasonal Affective Disorder (SAD)
- Symptoms
- Depression -weight gain
- Over sleeping
- Fatigue
- loss of concentration
Produces too much Melatonin. (a.k.a. Sleep
Hormone)
Melatonin causes other endocrine glands to
slow/stop production.
56- Treatment
- Light Therapy
- Antidepressants
- Moving to sunnier climate
- Quick Facts
- Occurs during fall through winter months
- Called Winter Blues
- Reverse SAD
- Information By Mayo Clinic Medline Plus
57- Symptoms fatigue, nervousness, headaches,
depression, dizziness, sudden hunger, a craving
for sweets, faintness - Treatment eating or drinking a small amount of
glucose-rich food, eat small and frequent meals
during the day