Endocrine Glands B- Exam 5

Hypothalamus releases..

releases releasing hormone which stimulates stimulating hormone secretion from anterior pituitary

hypothalamus controls… (7)

appetite, body temp, sleep, learning, memory, partially P.S. + S nervous system, emotional behaviors

Pituitary gland has how many lobes

3 lobes, anterior, intermediate, posterior

Anterior Pituitary Hormones- Thyroid Releasing Hormone

stimulates TSH and Prolactin

Anterior Pituitary Hormones- Cortisol Releasing Hormone

stimulates ACTH

What does ACTH stimulate?

aldosterone

Anterior Pituitary Hormones- Growth Releasing Hormone

Stimulates GH

Anterior Pituitary Hormones- GNRH ( gonadotropin releasing hormone)

stimulates FSH and LH

FSH function

controls egg development + follicle maturation in female and sperm production in male

LH function

controls ovulation in females and testosterone secretion in males

Posterior Pituitary Hormones (2)

oxytocin and ADH

How are Posterior Pituitary Hormones released

secretion by 2 nuclei in hypothalamus, supra optic and paraventricular nuclei axons, which carry hormones to posterior pituitary for storage

Clinical Point: Oversecretion of GH

can cause gigantism or acromegaly, can give synthetic somatostatin C

Clinical Point: Oversecretion of Prolactin

can cause infertility through hyperprolactinemia, can use synthetic dopamine (bromocriptine medication)

parts of Adrenal Gland

adrenal cortex and adrenal medulla

Adrenal Cortex parts- Zona glomerulus

secretes aldosterone which is sensitive to a decrease in blood sodium and low blood pressure

Adrenal Cortex parts- Zona fasciculata

secretes cortisol

Adrenal Cortex parts- Zona reticularis

secretes androgen

mechanism of aldosterone

renin secreted by kidney → angiotensin 1 → ACE from lung → angiotensin 2 acts as vasoconstrictor→ aldosterone is secreted

aldosterone function

reabsorb sodium chloride, H2O, HCO3- into blood and excretes K+ and H+ into urine

Coritsol Function (5)

maintain blood glucose, controls stress, inc appetite, suppresses inflammation, supresses immune system

Androgen

male sex hormone, but females also have it. It is the first hormone that becomes active in female puberty, controls axillary hair growth

Addison’s Disease- cause

deficiency of aldosterone, cortisol, and androgen

Addison’s Disease- S/S

hypertension, low blood Na+, high blood K+, inflammation, affected immune system, loose body hair (dec androgen)

Cushing Syndrome- cause

Oversecretion of aldosterone, cortisol, and androgen

Cushing Syndrome- S/S

obesity, upper limb/ lower limb hyperglycemia, inflammation, anxiety, affected immune system, hypertension, inc in blood Na+ and dec in blood K+ (hypernatremia)

Cohn’s Disease- cause

specific tumor of aldosterone producing cells, leads to oversecretion of it

Cohn’s Disease- S/S

hypertension, headache, inc in blood Na+, dec in blood K+, inc in blood HCO3-

Adrenal medulla secretes

epinephrine and norepinephrine

precursors of epinephrine and norepinephrine

tyrosine → dopa → dopamine → norepinephrine → epinephrine

epinephrine function

maintains blood glucose by liver and w/ norepinephrine controls blood pressure

Thyroid Gland- location

between 2 cartilages, hyoid bone, and first ring of trachea

Thyroid Gland- lobes and whats between them

left and right lobes with isthmus in between

Thyroid Gland- Blood Supply

very important because it carried iodide to tissue, inside gland there are follicle cells and in those there are thryoglobulin proteins

Steps of Iodide to iodine

thyroid gland contains follicle cells which contain TSH in cell membrane. When TSH binds to TSH receptor it leads to release of iodide into follicle cells, by sodium symport, oxidation of iodide occurs which converts to iodine by peroxidase

organification of I² - one iodine

when one iodine combines with tyrosine part of tyroglobulin it forms monoiodotyrosine (MIT)

organification of I² - two iodine

two iodines + tyrosine part of tyroglobulin forms diiodotyrosine (DIT)

What are MIT and DIT important for

they are inactive forms and are 1st step to T3 and T4 formation

Coupling of MIT and DIT- 1 of each

1 MIT + 1 DIT= T3 (triiodotyronin)

1 DIT + 1 DIT =

T4 (thyroxine)

T3 and T4 function together

are active, T4 is able to pass through placenta membrane, then converts to T3 which controls fetal bone development and fetal CNS development

What kind of receptor do T3 and T4 bind to? then what happens?

nuclear receptor, they are carried in by carrier protein so they can bind to nuclear receptor

What kind of receptor does TSH bind to ?

cell surface receptor

Effect of Thyroid Hormone (6)

1. from pregnancy, maternal T3 and T4 have direct effect on fetal bone and CNS development

2. controls body metabolism

3. controls memory and learning in adult

4. controls body temp

5. indirectly inc sensitvity of alph 1 and beta 1 to norepinephrine, indirectly inc blood pressure and heart rate

6. inc oxygen consumption by different organs

Clinical Point: If mother has hypothyroidism what can occur? treatment? S/S?

can lead to mental and bone growth retardation in newborn called congenital hypothyroidism. If caught in time, hormonal replacement is started from day 1 of life

S/S: motor, disorder, speech disorder, learning disorder

Thryoiditis

inflammation and infection of thyroid gland by bacterial, viral, fungi, autoimmune

autoimmune thyroiditis

famous, based on antibody which destroys tissue- hasimato’s

What percent of thyroiditis converts into hypothyroidism and hyperthyroidism

80-90% into hypothyroidism, 10% into hyperthyroidism

Hyperthyroidism- primary cause

oversecretion of T3 and T4, issue in thyroid gland

hyperthyroidism- secondary cause

oversecretion of T3 and T4, issue in hypothalamus or CNS

Hyperthyroidism- S/S and treatment

loose weight, excess sweating, feel hot, palpitation, heart disease, nervousness, irritates CNS, sleep disorder, oily skin and hair

treatment: if tumor remove, if infection treat it

Hypothyroidism- primary cause

deficiency of T3 and T4, issue in thyroid gland such as infection or tumor

Hypothyroidism- secondary cause

deficiency of T3 and T4, issue in hypothalamus or pituitary gland

Hypothyroidism- S/S and treatment

weight gain, learning issues, memory problem, feel cold, dry skin and hair, low blood pressure and heart rate, long term can cause heart failure

treatment: remove tumor or hormone replacement

Gestational Diabetes

can occur when mother has hypothyroidism during pregnancy due to hormonal changed

Mother with Type 2 diabetes and pregnant

newborn will have severe obesity

Metabolic effect of thyroid hormones (3)

1. inc glucose absorption

2. inc glycogenolysis, gluconeogenesis, lipolysis

3. controls protein synthesis