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Unit 6: Endocrine System Lauren Palla, Period 6 - Coggle Diagram
Unit 6: Endocrine System Lauren Palla, Period 6
Major Functions
Endocrine System
- coordinates and integrates activity of body cells
Influences metabolic activities via hormones in blood
Responses slower but longer lasting than Nervous System responses
Endocrine System controls and integrates:
Reproduction
Growth and Development
Maintenance of electrolyte, water, and nutrient balance of blood
Regulation of cellular metabolism and energy balance
Mobilization of body defenses
Major Endocrine Organs/Gland
Thoracic Cavity
Thyroid Gland
- butterfly-shaped gland in the anterior part of trachea
Secretes TH found in two forms:
Thyroxine (T4)
Triiodothyronin (T3)
Effects include:
Increases basal metabolic rate an d heat production
Regulates tissue growth and development
Maintains blood presure
TH release is regulated by negative feedback
Falling TH levels -> release of
thyroid-stimulating hormones (TSH)
Rising TH levels -> inhibition of TSH
Parathyroid Gland
- four to eight tiny gland yellow-brown glands embedded at posterior thyroid; secretes
PTH
to skeleton, kidneys, and intestines
Enhances reabsorption of Ca2+ and secretion of phosphate by kidneys
Promotes activation of vitamin D by kidneys -> increase absorption of CA2+
Stimulates osteoclasts to digest bone matrix and release Ca2+ to blood
Thymus
- releases
thymulin, thymopoietins, and thymosin
to immune response
Involved in normal development of T lymphocytes
Protects body from infection
Abdominal Cavity
Adrenal Gland
- paired, pyramid- shaped organs atop kidneys
Adrenal Cortex
- 3 layers of glandular tissue that synthesize and secrete different hormones; produces 24 hormones called
corticosteroids
Glucocorticoids
- influences metabolism of cells, keep blood glucose level relatively constant, and maintains bloodpressure
Cortisol
- is released in response to ACTH and increases glucose, fatty acids, and amino acids in blood
Gonadocorticoids
- weak antrogens -> testosterone and sometimes estrogen
Androstenedione, DHEA
- contributes to onset puberty and appearance of secondary characteristics; contributes to sex drive in women
Mineralocorticoids
- regulate electrolyte concentrations
Aldosterone (ADH)
- stimulates Na+ reabsorption by kidneys and K+ elimination. It also increases blood pressure.
Adrenal Medulla
- nervous tissue that's part of sympathetic nervous system
Synthesizes in
Epinephrine
and
Norepinephrine
Controls vasoconstriction
Increases heart rate
Increases blood glucose levels
Blood is diverted to brain, heart, and skeletal muscles
Pancreas
- triangular gland partially behind stomach; has both exocrine and endocrine cells
Glucagon
- raises blood glucose levels by by targeting liver; breaks down glycogen to glucose
Insulin
- lowers blood glucose level by enhancing membrane transport of glucose to fat/muscle cells
Cranial Cavity
Pineal Gland
- releases
melatonin
to brain
Controls Sleep/Wake Cycles
Affects timing of sexual maturity/ puberty
Affects physiological processes (ex. body temperature, sleep, appetite) that show rhythmic variations
Affects production of antioxidant and detoxification molecules
Pituitary Gland
- has two major lobes
Posterior Pituitary
- composed of neural tissue that secretes neurohormones and makes up neurohypophysis. It releases
oxytocin
and
ADH
Oxytocin
- string stimulant of uterine contractions released during childbirth; is released to the breast and uterus
Acts as neurotransmitters in brain
Acts as hormonal trigger for milk ejection
Antidiuretic Hormone (ADH)
- regulates high solute concentrations in blood; get released to the kidneys
Targets kidney tubules to reabsorb water
Prevents urinary contraction
Anterior Pituitary
- (adenohypophysis) consists pf glandular tissue
Growth Hormone (GH)
- has direct actions on metabolism and indirect growth promotion; targets bones
Thyroid-stimulating Hormone (TSH)
- stimulates normal development and secretory activity of thyroid
Adrenocorticotropic Hormone (ACTH)
- releases
corticosteroids
to adrenal cortex
Follicle-stimulating Hormone (FSH)
- stimulates production of gametes (egg/sperm) to reproductive organs
Luteinizing Hormone (LH)
- promotes the production of
gonodal hormones
and targets the reproductive organs
Prolactin (PRL)
- stimulates milk production in females and targets the breast
Hypothalamus
- releases an inhibits hormones to anterior pituitary
Regulates hormones being released in the body
Pelvic Cavity
Gonads
- produces same steroid sex hormones as the adrenal cortex, but in lesser amounts
Ovaries produce estrogens and progesterone (hormones found in women)
Estrogen
- causes maturation of reproductive organs and appearance of secondary sexual characteristics
Progesterone
- causes breast development and cyclic changes in uterine mucous
Testes produce testosterone (hormone found in men)
Testosterone
- same functions as estrogen but for men; necessary for normal sperm production
Homeostasis Mechanisms of Hormone Regulation
Blood level of hormones are controlled by
negative feedback
systems. Increased hormone effects on target organs can inhibit hormone release.
Endocrine Gland Stimuli
- are stimulated to synthesize and release hormones in response to 3 stimuli:
Neural
- nerve fibers stimulate hormone release
Hormonal
- hormones stimulate endocrine organs
Humoral
- changes in blood levels of ions and nutrients
Nervous System Modulation
- Nervous System can make adjustments to hormone levels when needed
Can override normal endocrine controls (ex. under severe stress, hypothalamus and sympathetic N.S. override insulin to allow blood glucose level to increase)
Prepares body for "fight or flight"
Can modify stimulation/inhibition of endocrine glands
Positive feedback
happens when hormones amplify an action outputted by the body (ex. oxytocin is a strong stimulant released during childbirth)
Steroid Hormones v. Non-steroid Hormones
Hormones
- long-distance chemical signals that travel in the bloodstream. They can be classified into two types:
Amino Acid-based Hormones
(non-steroid)
Includes amino acid derivatives, peptides, proteins
Epinephrine
Norepinephrine
It is water soluble
These type of hormones are polar, meaning they can not travel through the membrane; they have to bind themselves to target cell receptors on the outside of the cell
Steroids
Synthesized from cholesterol
Includes gonadal and adrenocortial hormones
Cortisol
Testosterone
Estrogen
Progesterone
It is lipid soluble (fats)
These type of hormones are non-polar, meaning they can travel through the cell membrane; they can bind themselves to target cell receptors on the inside of the cell
Hormones get produced by
endocrine glands
, which contain no ducts
Parathyroid
Adrenal
Thyroid
Pineal
Pituitary
Endocrine System Diseases
Diabetes Insipidus
- ADH deficiency due to damage to hypothalamus or posterior pituitary.
Must keep well hydrated
Symptoms include frequent urination
Hypersecretion
of GH is usually caused by tumor in the anterior pituitary
Gigantism
- a condition in children that can cause them to reach 8 ft tall
Acromegaly
- a condition in adults that can cause overgrown hands, feet, or face
Hyposecretion
of GH
Pituitary Dwarfism
- a condition found in children that can cause them to stop growing at 4 ft.
Myxedema
- hyposecretion of TH in adults
Symptoms include:
Low metabolic rate
Thick/dry skin
Constipation
Puffy eyes
Lethargy
Chills
Lack of iodine can lead to the enlargement of the thyroid (may cause goiter)
TH is critical for normal growth and brain development
Congential Hypothyroidism
- poor development of thyroid gland
Symptoms include:
Weak cry
Poor feeding
Prolonged Jaundice
Constipation
Can be caused by pituitary problems/ maternal medication
Grave's Disease
- hyposecretion of TH
Symptoms include:
Elevated metabolic rates
Sweating
Rapid ad irregular heartbeat
Increased nervousness
Weight loss
Exopthalmos
- protruding eyes
Body makes abnormal antibodies directed against thyroid follicular cells. These antibodies mimic TSH, stimulating TH release
Treatment includes surgical removal/ radioactive iodine
Cushing Syndrome
- hypersecretion of cortisol due to a tumor in the pituitary, lungs, pancreas, kidney, or adrenal cortex
Symptoms include:
""Moon"" face
""Buffalo Hump"
Depresses cartilage/bone formation and immune system, as well as inhibits inflammation.
Disrupts neural, cardiovascular, and gastrointestinal tracts
Addison's Disease
- hyposecretion of cortisol
Symptoms include:
Weight loss
Severe dehydration
Bronzing of skin due to high levels of ACTH
Hypotension
Involves deficits in both glucorticoids and mineralocorticoids
Decrease in plasma glucose and Na+ levels
Diabetes Mellitus (MD)
Types of Diabetes:
Tyoe 1
- hyposecretion of insulin
Type 2
- hypoactivity of insulin
3 Cardinal Signs of DM:
Polyuria
- huge urine output
Polydipsia
- excessive thirst
Polyphagia
- excessive hunger/food consumption (cells are "starving")
Hyperinsulinism
- excessive insulin secretion
Symptoms include:
Anxiety
Disorientation
Unconsciousness
Death
May cause
Hypoglycemia
(low blood glucose levels)