Class 2 Flashcards
What 2 things form a unit and exert control over several endocrine glands?
- Hypothalamus
- Pituitary gland
Hypothalamus and Pituitary control function of what 3 endocrine glands?
- Thyroid
- Adrenals
- Gonads
The pituitary is also know as the what?
-Master gland
What is responsible for the brain-endocrine interactions?
-Hypothalamus pituitary axis
What is considered the coordinating center of the endocrine system?
-hypothalamus
The hypothalamus consolidates signals from what 4 things?
- Upper cortical inputs
- Autonomic function
- Environmental cues
- Peripheral endocrine feedback
What does the pituitary do? and what tells it what to do?
- Releases hormones
- receives precise signals from the hypothalamus
What bone does the pituitary reside and what is the area called?
- Sphenoid Bone
- Sella tursica***
What are the 4 divisions of the pituitary?
- Anterior (Largest)
- Pars intermediate (gone after development)
- Pars tubularis (Highly vascular, no hormones)
- Neurohypopysis
How are the anterior and posterior pituitary different?
- Different connection to hypothalamus
- Different cell types
- Secrete different hormones
What is another name for the anterior pituitary? And how is it connected to the hypothalamus?
- Adenohypophysis
- Portal venous system
The anterior pituitary is regulates what 6 things?
- Thyroid
- Adrenal
- Mammary gland
- Growth hormone
- Gonads
- Melanocytes
Name the 5 types of cells found in the anterior pituitary
- Somatotropes (most abundant)
- Corticotropes
- Thyrotropes
- Gonadotropes
- Lactotropes
What does the Somatotrope cell secrete?
-Growth hormone
What does the corticotroope cell secrete?
-Adrenocorticotropic Hormone (ACTH)
What does the thytropes cell secrete?
-Thyroid stimulating hormone (TSH)
What does the gonadotope cells secrete?
- Leutinizing Hormone (LH)
- Follicle stimulating hormone (FSH)
What type of cell secretes prolactin (PRL)?
-Lactotropes
The posterior pituitary is also called what? and is basically what?
- Neurohypophysis
- Axonal projections from the hypothalamus
What two hormones does the posterior pituitary produce and what do they do?
- Oxytocin (Uterine contractions)
- Vasopressin aka ADH (water balance
What does Vasopressin (ADH) do?
- Increase permeability of collecting ducts
- Increase free water absorption
- Contraction of vascular smooth muscle
Describe the vasopressin receptors.
- V1 = vasoconstriction
- V2 = Renal fluid reabsorption
In what two ways is vasopressin stimulated for release?
- Osmoreceptors sense plasma osmolality > 290
- Baroreceptors in carotid sinus and aortic arch sense large volume changes
What does syndrome of inappropriate ADH cause?
- Water retention
- Hyponatremia
- Concentrated urine
- Dilute plasma
When ADH works on the kidneys what does it do?
- Increase urine osmolality
- Decrease plasma osmolality
- Increase ECF
What can cause syndrome of inappropriate ADH?
- CNS disorders
- Cold stress
- Trauma
- Drugs
- Cancer / tumor
Describe the mild, moderate and severe symptoms of hyponatremia.
- Mild< 125: Anorexia, nausea, weakness
- Mod: Lethargy, confusion
- Severe <120 : seizures, coma, death
Sodium greater than what is safe for elective surgeries?
->130
Sodium less than 130 can lead to what?
- Cerebral edema
- Decrease in MAC**
- Agitation
- Confusion
- Somnolence
Rapid correction of sodium can lead to what problem? And when does it occur?
- Central pontine myelinolysis
- Change in Na > 0.5meq per hour
What are some risk factors for central pontine myelinolysis?
- ETOH
- Liver disease
- Malnutrition
- hyponatremia
Diabetes insipidus signs?
- Excessive thirst
- Dilute Urine
Diabetes is can be caused by what two mechanisms?
- Inability to release ADH (central)
- Inability of kidney respond to ADH
What is the net result of diabetes insipidus?
- Hyposmotic urine
- hyperosmotic plasma
- Polydypsia (excessive thirst)
Name 2 ways to treat diabetes insipidus?
- Desmopressin nasal spray = Central
- Demeclocycline = decrease in renal response to ADH
Describe hypernatremia
-Loss of H2O or excess of Na
How does hypernatremia effect MAC?*****
- Increased MAC
- Decreased uptake of inhalation agent
Surgery should be postponed for sodium greater than what?
> 150
Symptoms of hypernatremia?
- Restlessness
- Lethargy
- Hyperreflexia
- Seizure
- Coma
- Death
Oxytocin is secreted from what? and does what?
- Supraoptic nucleus of posterior pituitary
- Contractions of uterus and myoepithelial cells of lactating breast
What are 2 of the rare instances in which there is a positive feedback in the endocrine system?
- Labor effects
- Breast feeding
How is pitocin used in OB?
- Increase contractions of uterus during labor
- Contract uterus after birth to prevent blood loss
Complications of pitocin.
- Fetal distress
- Uterine stimulation
- Maternal water intoxication
Rapid infusion of pitocin can cause what?
- Htn
- Tachycardia
- N/V
- Seizures
Normal dose of pitocin.
-Usually 20 units (never more than 40) in a liter bag
What two ways are pituitary tumors found?
- Compression of adjacent structures (vision changes)
- Systemic effects of hormonal changes
Pituitary compression of the optic chiasm from a pituitary tumor can result in what?
-Bitemoral hemianopsia
Too much growth hormone causes what? and can lead to what?
- Acromegaly
- Difficult airway
Too much Thyroid stimulating hormone causes what?
- Hyperthyroid
- Tachycardia
- Weightloss
Elevated ACTH can cause what?
- Cushing’s disease
- Difficult airway
Panhypopituitarism requires what?
- Cortisol for adrenals
- Levothyroxine for thyroid
- DDAVP (vasopressin)
Possible problems post pituitary surgery? and what would you see?And what to treat?
- Diabetes insipidus
- Elevated urine out put with specific gravity < 1.005
- Treat with DDAVP
