1. Friday, 24 September Ch 11 Endocrine System The Hypothalamus and Pituitary Glands –Unique anatomy –Long & short loop negative feedback Stress and Cortisol Some examples of endocrine disorders

2. 1QQ # 8 for 8:30 class 1.Suppose a biopsy of a patient’s thyroid gland revealed follicles and follicular epithelial cells that were less than half the normal size. If you took a blood sample from that patient, would you predict the TSH level to be normal, high, or low. Explain your choice. 2.Your patient’s body temperature is 97.1 F, blood pressure and heart rate are below normal. You order a blood test to check for hormone levels. Which hormone(s) is/are of greatest interest to you and why? Based on the symptoms, what predictions do you make about the results of the blood test? Explain.

3. 1QQ # 8 for 9:30 class 1.Some tumors of endocrine glands result in unregulated high levels of hormone secretion. Which would you predict to be more severe: a tumor in the anterior pituitary gland or a tumor in the posterior pituitary gland? Explain your reasoning. 2.Your patient’s body temperature is 97.1 F, blood pressure and heart rate are below normal. You order a blood test to check for hormone levels. Which hormone(s) is/are of greatest interest to you and why? Based on the symptoms, what predictions do you make about the results of the blood test? Explain.

4. Tropic hormones control the function Trophic hormones promote survival and growth of targets Releasing HormoneRelease-inhibiting Hormone Hypothalamo-hypophyseal portal system A A S S P P PPP PP PPPP S 1

5. Tropic hormones control the function Trophic hormones promote survival and growth of targets Releasing Hormone Release Inhibiting Hormone Long-loop negative feedback Short-loop Neg. Feed. S 2

6. Endocrine disorders Hypersecretion –Primary –Secondary Hyposecretion –Primary –Secondary CRH ACTH Cortisol hypothalamus Anterior pituitary Adrenal Cortex S 3

7. Who Cares?

8. Symptoms of hypothyroidism Levels of TSH and TH? Explain enlarged thyroid gland Cause: Inadequate dietary intake of iodine Treatment? Endemic Goiter TRH TSH T3 & T4 Goiter Elevates basal metabolic rate, potentiates response to EPI If hypothyroid during pregnancy… cretinism = congenital hypothyroidism S 4

9. Who else Cares?

10. Aunt Dot S 5

11. T3 and T4 from Thyroid gland TSH from Ant. Pit. TRH from Hypothal. ⇧Metabolic rate ⇧Temperature ⇧sensitivity to EPI (up-regulation of adrenergic receptors) ⇧Heart rate and ⇧Blood Pressure ⇧Lipolysis and fuel mobilizationWeight loss The cause: Abnormal Immunoglobulins in patient activate TSH receptors on Thyroid cells ⇩ ⇩ Grave’s Disease S 6 Blood test: TSH levels low TH levels high

12. Grave’s Disease Treatment: Radioactive Iodine Mechanism:…….. S 7

13. ⇧Cortisol secretion from Adrenal Cortex Mobilize fuel from muscle & adipose tissue Suppress non-essential functions (reproduction & growth) Suppress inflammatory & immune responses Potentiates response to EPI (vascular smooth muscle) ACTH from Ant. Pit CRH from Hypothalamus Physical trauma Prolonged exposure to cold Prolonged intense exercise Infection Sleep deprivation Pain Fright Emotional distress Vasopressin Cytokines from immune cells Excess Cortisol from 1) adrenal cortex tumor (primary) or 2) hypersecretion of ACTH from anterior pituitary (secondary) Cushing’s Syndrome Basal levels of Cortisol Required for normal sensitivity to EPI; symptoms of excess cortisol are….. Clinical example: treatment of chronic inflammation (e.g. arthritis) can lead to Cushing’s Syndrome! S 8

14. Applied Physiology: Menopause Widmaier text p. 694 Onset ~ age 50 Irregular menstrual cycles Breasts and genital organs gradually atrophy Decrease in bone mass & strength (osteoporosis) (bone resorption greater than bone deposition) Hot flashes…sweating, etiology unknown Increased incidence of coronary artery disease S 9

15. Menopause, continued. Caused by ovarian failure….loss of estrogen Estrogen has protective function for cardiovascular system and sustains bone Diagnosis –Test estrogen levels –Test FSH levels….interpretation if high? Treatment –Hormone replacement therapy –Risk of HRT: increased incidence of breast cancer & uterine endometrial cancer –Advantages: alleviates symptoms, restores cardiovascular protection, sustains bone density S 10