Unit 2: Chp 40: Assessment of Endocrine Function Flashcards
Endocrine Glands
- hypothalamus
- pituitary gland
- thyroid glands
- parathyroid glands
- gonads
- select cells of the pancreas (Islet cells)
What do the Endocrine Glands do?
secrete hormones that are chemical messengers that act on specific target tissues, resulting in physiological functions
-hormones are secreted directly into the blood system
Exocrine Glands
-lacrimal
-salivary
-sweat glands
>hormones are released from ducts
Function of the Endocrine System
directly associated w/ secretion and levels of circulating hormones
-primary, secondary, tertiary, and quaternary disorders
Primary Disorders
involve actual dysfunction to the endocrine gland
Secondary Disorders
dysfunction of the anterior pituitary gland
Tertiary Disorders
dysfunction of the hypothalamus
Quaternary Disorders
inability of the target tissue to respond to the hormone
How is the Secretion of Hormones Regulated?
via signals from the nervous system, levels of hormones in the blood, and chemical changes in the blood such as glucose, sodium, and potassium levels
-controlled by negative-feedback system
Negative-feedback System
increases hormone secretion when circulating levels are decreased
Safety Alert: Corticosteroids
pts prescribed corticosteroids for more than 10 to 14 days require “tapering” of the medication
- b/c of the effects of the exogenous corticosteroid on the hypothalamus, anterior pituitary, and adrenal cortex, the normal hormonal feedback system is interrupted
- abrupt withdrawal of the exogenous drug may lead to adrenal insufficiency; medical emergency; decreased blood pressure and hypoglycemia
Use of corticosteroids
for inflammation
- impact function of the negative feedback system
- b/c there are increased circulating levels of corticosteroid, the hypothalamus decreases secretion of corticotropin-releasing hormone; leads to decreased secretion of adrenocorticotropic hormone (ATCH) from anterior pituitary gland which results in decreased secretion of cortisol from the adrenal cortex
Hypothalamus
- small structure located beneath the thalamus
- shaped like a flattened funnel and forms the walls and floor of the third ventricle
- hormones produced and secreted by the hypothalamus act directly on other endocrine glands (ex: pituitary gland)
- connected to the pituitary gland by the infundibulum
- regulates anterior pituitary gland function through the secretion of hormones whose target tissue is the anterior pituitary gland
Pituitary gland
- located at the base of the brain
- communicates directly w/ hypothalamus
- anterior and posterior lobe
Anterior Pituitary Gland
- secretes follicle stimulating hormone (FSH) and luteinizing hormone (LH); major roles in female and male reproductive functions
- secretes thyroid-stimulating hormones
- releases adrenocorticotropic hormone (ACTH)
- secretes prolactin, growth hormone (GH), and melanocyte-simulating hormone
Posterior Pituitary Gland
secretes antidiuretic hormone (ADH) and oxytocin
Adrenal Glands
located on top of each kidney
-has inner cortex, the medulla, and a thick outer covering, the cortex
Adrenal Cortex
comprises 90% of the adrenal gland
- secretes Mineralocorticoids that control fluid balance through their effects on the kidneys; absorption of sodium and water and excretion of potassium
- secretes Aldosterone (primary mineralocorticoid)
- secretes glucocorticoids (primary is cortisol); have an effect on carbohydrate, protein, and fat metabolism; suppress inflammatory and immune functions
Adrenal Medulla
- under control of sympathetic nervous system
- catecholamines (norepinephrine and epinephrine) are secreted when stimulated by the SNS
Thyroid hormone
- produces triiodothyronine (T3), thyroxine (T4), and thyrocalcitonin (calcitonin)
- calcitonin decreases serum calcium levels
Parathyroid Glands
- secrete parathyroid hormone (PTH); in response to low calcium levels
- target organs of PTH are bones, kidneys, and small intestine
- PTH increases serum calcium levels
Gonads
sexual development and function are controlled by hormones secreted from ovaries and testes
- both ovaries and testes are controlled by tropic hormones released from the anterior pituitary gland based upon secretion of gonadotropin releasing hormone from the hypothalamus
- follicle-stimulating hormone (FSH) and luteinizing hormone (LH) stimulate maturation of male and female reproductive organs
- In males, FSH and LH stimulate testosterone
- In females FSH and LH stimulate estrogen and progesterone that influence development of secondary sexual characteristics, ovarian maturation, and ovulation
Pancreas
- located in upper left quadrant
- secretes pancreatic juices into the small intestine to aid in digestion
- blood glucose control by the islet cells
- releases insulin and glucagon
Assessment: History
-nurse completes a comprehensive history
-b/c the endocrine system affects homeostasis and metabolic activity, the nurse must assess changes in:
>nutritonal status
>physical appearance
>weight
>sleep pattern
>energy
>elimination pattern
>reproductive function
>evaluating family history for endocrine disorders; some are genetic
Physical Assessment: Inspection
-head-to-toe assessment; b/c changes in physical appearance
>ex: elevated levels of growth hormone (GH), a broadening of forehead or jaw may be noted
>Ex: elevated cortisol; puffiness of the face
Physical Assessment: Auscultation
- auscultates the chest to assess cardiac rate and rhythm b/c some endocrine disorders affect cardiovascular function
- in hyperthyroidism, tachydysrhythmias may occur and may be auscultated
- b/c of increased vascularity associated with hyperthyroidism, listen over the carotid arteries for carotid bruits
- listen over the thyroid gland with hyperthyroidism b/c it can reveal a thyroid bruit b/c of increased thyroid vascularity
Assessment: Palpation
- to assess testes and the thyroid glands: evaluated for size, symmetry, shape, and any nodules or changes in texture
- thyroid gland palpated best standing behind the patient
How to Palpate Thyroid Gland
- stand behind patient
- the thumbs of both hands are placed on the back of the neck, and the fingers are curved to the front of the neck on either side of the trachea
- patient is asked to swallow, and the nurse locates the isthmus by feeling it rise when the patient swallows
- nurse assesses both right and left lobes of the thyroid gland; right lobe palpated when head turned to the right and vice vera; assess for irregularities or nodules
Diagnostic Studies for Suspected Endocrine Disorder
- laboratory assessment of urine and blood samples
- imaging studies
- measurements of circulating hormones (ex: T3, T4, TSH levels)
- stimulation and suppression tests
Stimulation Testing
a selected hormone is administered to stimulate the target tissue to produce its hormone
-failure of the target to secrete sufficient hormone indicates hypofunction of that gland
Suppression Testing
indicated when there are excess levels of circulating hormone
-when levels of circulating hormone do not decrease with suppression testing, hyperfunction of the gland is confirmed
Imaging Studies
diagnostic imaging studies are indicated to assess for changes in the size or presence of tumor formation in the glands of the endocrine system
-Computed tomography (CT), Magnetic Resonance imaging, and X-rays used to confirm abnormalities of the endocrine glands
Connection Check: A patient is undergoing a stimulation test to assess adrenal function. After the administration of cortisol, which laboratory result indicates normal function? A. Decreased blood glucose B. Decreased serum sodium C. Decreased serum potassium D. Decreased serum calcium
C. decreased serum potassium
Age-Related Changes
- menopause; also a “normal state” of ovarian hormone deficiency that affects all women as they age
- physiological changes caused by menopause are usually diminished with the use of hormone replacement therapy
- downregulation (decreased number of receptors on the surface of the target tissue)
- hormone production, secretion rates, and tissue responsiveness decrease w/ age
- decreased metabolism associated w/ decreased appetite, susceptibility to cold intolerance, changes in the quality of sleep, and decreased resting pulse rate and blood pressure
- changes in release of reproductive hormones may lead to problems with sexual functioning, including erectile dysfunction, and decreased libido
- pts w/ decreased glucose tolerance may present with elevated blood glucose levels and weight gain
- decreased synthesis of ADH in the older adult is associated w/ increased urine frequency and dilute urine, leading to an increased risk of dehydration
- bone density decreases
- thinning and drying of the skin
- perineal and vaginal dryness
Chapter Summary
Endocrine system consists of glands located throughout the body that are essential to many vital functions
- hypothalamus plays a major role in endocrine function; controls the anterior and pituitary glands
- hormones from the anterior pituitary gland control the function of the adrenal glands, thyroid glands, and reproductive organs
- growth hormone (GH) controlled by the anterior pituitary gland
- posterior pituitary gland secretes antidiuretic hormone (ADH) that maintains fluid volume balance by promoting water reabsorption in the kidneys, and sexual hormones
- the adrenal cortex, under control of ACTH, secretes mineralocorticoids and glucocorticoids
- aldosterone, primary mineralocorticoid, promotes sodium reabsorption in the kidneys and excretion of potassium
- cortisol, primary glucocorticoid, promotes gluconeogenesis and glycogenolysis that lead to an increase in blood glucose levels
- glucocorticoids have a major role in growth and development, and anti-inflammatory actions
- adrenal medulla release catecholamines (epinephrine, norepinephrine)
- thyroid gland secretes hormones that influence metabolic activity (triiodothyronine (T3) and thyroxine (T4)
- thyroid gland secretes thyrocalcitonin that lowers serum calcium levels
- parathyroid hormone (PTH) plays a major role in calcium regulation; increase in PTH increases serum calcium levels, a decrease in PTH lowers serum calcium
- maturation of female and male reproductive organs is facilitated by hormones produced by the anterior pituitary gland (follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
- estrogen and progesterone are key to normal female functioning including controlling the menstrual cycle, facilitating and maintaining pregnancy, and development of secondary sexual characteristics
- testosterone is required for sperm production and development of secondary male sexual characteristics
- pancreas controls regulation of blood glucose levels and carbohydrate, fat, and protein metabolism through the release of insulin and glucagon
- glucagon increases blood glucose levels through gluconeogenesis and glycogenolysis
- insulin lowers blood glucose levels by facilitating the movement of glucose into the cells
Homeostasis
body is always looking to keep things in balance
-our endocrine disorders are either too much or not enough of a specific hormone
