Exam 5: Endocrine System Flashcards
synthesize substances that are released into ducts connecting to another structure
exocrine glands
synthesizes and releases hormones into the bloodstream
Anterior Pituitary Gland
acts on the thyroid gland to release thyroid hormone
Thyroid-Stimulating Hormone
What hormone is released when cold or stressed
Thyroid-Stimulating Hormone
acts on all body tissues (especially bones and muscles) to stimulate growth and size of the body.
Growth Hormone
act on the gonads (testes and
ovaries) to stimulate the development of gametes (sperm cells and oocytes).
Follicle-Stimulating Hormone and Luteinizing Hormone
acts on the mammary glands of the breast to stimulate growth and milk production (not ejection).
Prolactin
acts on the adrenal cortex to cause the release of
corticosteroids
Adrenocorticotropic Hormone
acts on the malanocytes in the skin to produce melanin.
Melanocyte-Stimulating Hormone
the hypothalamus controls the anterior pituitary gland by…
releasing its regulating
hormones into the Hypothalamic-Hypophyseal Portal System.
is a capillary plexus surrounding the anterior pituitary gland.
Hypothalamic-Hypophyseal Portal System
venous blood carrying regulating hormones from the hypothalamus to the plexus are
called
hypophyseal portal veins.
the regulating hormones leave the…
capillary plexus to have an effect on the anterior pituitary
the anterior pituitary releases its hormones into the __ and carried __
capillary plexus, away by. hypophyseal vein
hypophysis
Pituitary gland
Pituitary gland is suspended from the
hypothalamus by a stalk or infundibulum.
Pituitary gland is divided
structurally and functionally, into anterior and posterior parts
Synthesize substances that are released into ducts connecting to another structure
Exocrine glands
Synthesize substances that are released into the bloodstream to effect target tissue
Endocrine gland
Single gland or be scattered through tissues
Endocrine
What works together to keep body in homeostasis
Endocrine and nervous system
Substances released into the bloodstream to have an effect on target structures
Hormones
Endocrine cells produce
Hormones
Hormone levels in blood are regulated by
Self adjusting mechanisms or feedback loops
React to hormone only if they have the receptor for it
Target cells
Most of endocrine levels in blood are regulated by
Negative feedback loop
A negative feedback loop..l
reduces own hormone production
Example of negative feedback loop
Eat, Blood glucose increases, insulin released, body tissue takes up glucose, blood glucose decreases
Positive feedback loop…
Hormone continued to be produced
Example of positive feedback loop
Baby breastfeeds, stimulus to hypothalamus, pituitary gland signaled to produce oxytocin, oxytocin stimulates milk ejection, baby continues to suck
Oxytocin function
Stimulates milk ejection
Master controller of endocrine system
Hypothalamus
Hypothalamus controls the
Endocrine functions
Ways hypothalamus controls endocrine functions of the body….
- Produces regulatory hormones that effect anterior pituitary gland (stimulate or inhibit release)
- Produce hormones that are transported and stored in posterior pituitary gland until needed.
- Stimulates sympathetics to medulla to release adrenaline
Produces own hormones
Anterior pituitary gland
Overseer of ANS
Hypothalamus
The stalk of the pituitary gland is made up of
Nerve axons running from hypothalamus into posterior part
There are ___ in hypothalamus whose axons make up the __
Two nuclei, stalk
Carry hormones to posterior pituitary gland for storage
Two nuclei in hypothalamus
Neurons In paraventricular nucleus…
Synthesize and transport oxytocin to posterior pituitary gland
Transport oxytocin
Paraventricular nucleus
Neurons in supraoptic nucleus…
Produce and transport anti-diuretic hormone to posterior pituitary gland
Anti diuretic hormone associated with
Supraoptic neurons
The posterior pituitary does not
Produce its own hormone just stores oxytocin and antidirectic
Posterior pituitary gland release the hormones into its own
Capillary plexus
Stimulates ejection of milk, not production, during breastfeeding
Oxytocin
Causes contraction of smooth muscle of uterus during birth
Oxytocin
In males, oxytocin causes the…
Contraction of the prostate gland to release its products
Released when blood volume is low
Anti diuretic hormone
Causes water to be retained by kidneys to help increase blood volume
Anti diuretic hormone
Causes vasoconstriction
Anti diuretic hormone
Helps increase BP
Vasoconstriction
Largest endocrine gland in body
Thyroid gland
Thyroid gland is located in
Lower neck, near trachea
The thyroid has right and left lobes connected by
Isthmus
Thyroid gland Gets blood supply through
Superior and inferior thyroid arteries
Regulates metabolic activity of cells in body
Thyroid hormone
Follicles are
Follicular cells surrounding a cavity with colloid
Contains precursors of thyroid hormone
Colloid
Produces thyroid hormone
Follicular cells
Essential nutrient for thyroid hormone production
Iodine
Example of negative feedback with thyroid
Low body temperature cause hypothalamus to secrete TRH, release TSH, TSH stimulates follicular cells to produce TH, TH targets cells increase metabolic activities, body temp increases and hormones inhibited
If TSH is high, than the thyroid is
Not working well, from anterior pituitary gland
Enlargement of thyroid gland due to lack of iodine in diet
Goiter
An immune disorder that results in hyperthyroidism
Graves’ disease
Bulging of eyes seen with Graves’ disease
Exophthalmos
Other signs of Graves’ disease
Anxiety, weight loss, irregular heartbeat
Typically 4 embedded in posterior thyroid gland
Parathyroid gland
Cells in the parathyroid gland produce
PTH
Parathyroid hormone function
Regulates blood calcium levels
You need blood calcium for
Muscular and nervous system
Parathyroid hormone (PTH) is released into bloodstream in response to
Low blood calcium levels
Parathyroid hormone (PTH) in the bloodstream causes
- osteoclasts to release calcium from bone
- kidneys to reabsorb calcium from tubular fluid
- small intestine to absorb calcium
Not under the control or hypothalamus
Parathyroid glands
Chromaffin cells release epinephrine and norepinephrine into bloodstream,
Medulla
Release epinephrine and norepinephrine into bloodstream
Chromaffin cells
Cortex has three layers or zones known as…
Zona glomerulosa, fasciculata, reticularis
Outermost later of cortex
Zona glomerulosa
Secretes mineralocorticoids to regulate composition of electrolytes in the body
Zona glomerulosa
Adolsterone is a
Mineralcorticoid
Secretes glucocorticoids which stimulate metabolism of lipids and proteins to regulate blood glucose levels
Zona fasciculata
Cortisol is a
Glucocorticoid
Secretes gonadocorticoids
Zona reticularis
Androgens are
Gonadocorticoids
Sugar in bloodstream
Glucocorticoid
Excessive glucocorticoid such as when taking corticosteroids as therapy for rheumatoid arthritis
Cushing syndrome
Symptoms of Cushing syndrome
Decrease bone mass, muscle weakness, redistribution of body fat, swelling
To little glucocorticoid, not enough blood sugar
Addison disease
Adrenal insufficiency
Addison’s disease
Signs of Addison disease
Weight loss, general fatigue and weakness, hypotension
Acinar cells are…
Exocrine part of pancreas
Produce digestive enzymes that enter duodenum through pancreatic duct
Acinar cells
Pancreatic islets include
Alpha and beta cells
Alpha cells secrete __ and beta cells secrete __
Glucagon, insulin
Cause cells in liver to break down glycogen into glucose
Glucagon
Facilitate movement of glucose from blood to tissues of body
Beta cells
Insulin also promotes
Glycogen synthesis in liver
Stimulated by high levels of nutrients in bloodstream
Delta cells
Delta cells synthesize
Somatostatin
Slows the release of insulin and activity in digestive organs
Somatostatin
Slows rate of nutrients entering bloodstream
Somatostatin
Metabolic condition marked by inadequate uptake of glucose from blood
Diabetes mellitus
Glucose in urine
Glycosuria
Chronically elevated blood glucose damages…
Smaller arteriole, kidney failure, retinal blindness, and amputation
Insulin dependent diabetes (can’t produce own insulin)
Type 1
Characterized by diminished production of insulin by islet cells
Type 1
Tends to occur in children
Type 1
Patients have a genetic predisposition
Type 1
What cells are mainly affected in type 1 diabetes
Beta cells
Treatment of Type 1 diabetes
Daily insulin injections
Blood glucose can’t be delivered to tissues of body
Type 1
Insulin independent diabetes
Type 2
Results from either decreases insulin release by beta cells or decreases insulin effectiveness at peripheral tissues
Type 2
Occurs in adults and obesity plays a role
Type 2
Treatment of type 2 diabetes
Dietary changes, exercise
