1. Endocrine System

2. Endocrine System
1H16.01 Explain the structure of the endocrine system.
Pituitary gland
Tiny structure size of grape
Located at base of brain
Connected to hypothalamus
Divided into anterior and posterior lobes
Thyroid gland
Butterfly-shaped mass of tissue
On either side of larynx, over trachea
H-shaped
Parathyroid glands
Four glands, each the size of a grain of rice
Attached to posterior thyroid

3. Endocrine System Thymus Endocrine gland and lymphatic organ
Located behind sternum, above and in front of heart
Begins to disappear at puberty
Adrenal glands - located on top of each kidney
Gonads
Ovary in female
Testes in male
Pancreas
Located behind the stomach
Endocrine and exocrine functions

4. Endocrine System 1H16.02 Analyze the function of the endocrine system
Types of glands
Endocrine
Secrete hormones directly into bloodstream
Ductless
Exocrine
Secrete substance through a duct
Sweat, salivary, lacrimal and pancreas
Function of endocrine system
To secrete hormones
Hormones are chemical messengers that coordinate and direct target cells and organs

5. Endocrine System Hormone control
Negative feedback – drop in hormone level triggers a chain reaction
Blood level of hormone falls
Brains gets message and sends out hormone to stimulate gland
Gland secretes more hormone
When blood level of hormone increases, brain hormones stop
Nervous control – in some cases, sympathetic nervous system causes direct release of hormone from gland (for example, when stress causes the adrenal medulla to secrete adrenalin)

6. Endocrine System Pituitary gland (The master gland)
Anterior pituitary lobe
Growth hormone – GH (somatotropin) responsible for growth and development
Prolactin – develops breast tissue, stimulates production of milk after childbirth
Thyroid-stimulating hormone – TSH – stimulates thyroxine
Adrenocorticotropic hormone – ACTH – stimulates adrenal cortex
Follicle-stimulating hormone – FSH – stimulates growth of graafian follicle and production of estrogen in females, sperm in males
Luteinizing hormone – LH – stimulates ovulation and formation of corpus luteum, which produces progesterone in females
Posterior pituitary lobe
Vasopressin – converts to ADH (antidiuretic hormone) in the bloodstream, acts on kidney to concentrate urine and preserve H2O in the body

7. Endocrine System Thyroid gland
Oxytocin – released during childbirth causing contractions of the uterus
Thyroid gland
1. Main hormone, thyroxine, is controlled by secretion of TSH
Thyroxine controls the rate of metabolism
Calcitonin, another hormone that controls calcium ion concentration in the body, prevents hypercalcemia
Parathyroid glands – produce parathormone which helps control blood calcium, prevents hypocalcemia
Thymus
Endocrine gland and lymphatic organ
Located behind sternum, above and in front of heart
Begins to disappear at puberty

8. Endocrine System Adrenal glands
Adrenal cortex secretes corticoids (anti-inflammatory hormones) and sex hormones
Androgens – male sex hormones
Adrenalin – hormone from adrenal medulla, powerful cardiac stimulant, “fight or flight” hormone
Gonads
Estrogen – development of female reproductive organs, secondary sex characteristics
Progesterone – plays a part in the menstrual cycle
Testosterone – male reproductive organs and secondary sex characteristics

9. Endocrine System Pancreas Islets of Langerhans – insulin production
Insulin promotes utilization of glucose by the cells
Prostaglandins – tissue hormone
1H16.03 Discuss characteristics and treatment of common endocrine disorders.
Gigantism
Hyperfunction of pituitary – too much growth hormone
In preadolescence – overgrowth of long bones leads to excessive tallness
Dwarfism
Hypofunction of pituitary in childhood
Small size, but body proportions and intellect normal
Rx – early diagnosis, injection of growth hormone

10. Endocrine System Hyperthyroidism Overactive thyroid gland
Too much thyroxine leads to enlargement of gland
Symps – consuming large quantities of food but lose weight
Goiter – enlargement of gland
Exophthalmos – bulging of eyeballs
Rs – partial or total removal of gland, drugs to reduce thyroxine, radiation
Hypothyroidism
Not enough thyroxine
May be due to lack of iodine (simple goiter)
Symps – dry, itchy skin; dry and brittle hair, constipation, muscle cramps at night

11. Endocrine System Tetany
Hypoparathyroidism, decreased calcium levels affect functions of nerves
Symps – convulsive twitching develops, person dies of spasms in the respiratory muscles
Rx – Vitamin D, calcium and parathormone
Diabetes Mellitus
Cause – decreased secretion of insulin
Symps – polyuria, polyphagia, polydipsia, weight loss, blurred vision, and possible diabetic coma
If not treated, excess glucose in blood (hyperglycemia) and secreted in urine (glycosuria)

12. Endocrine System
If too much insulin given, blood sugar can get too low (hypoglycemia) and person can develop insulin shock
Type II diabetes is not insulin-dependent – most common, usually familial, occurs later in life, usually treated with diet
Test for diabetes – blood sample at home, normal blood sugar is mg

13. Endocrine System Terminology
ACTH
ADH
adrenal glands
adrenalin
androgens
calcitonin
corticoids
endocrine glands
estrogen
exocrine glands
FSH
gonads
GH (somatotropin)
hormones
insulin

14. Endocrine System Terminology
islets of Langerhans LH
negative feedback
ovary
oxytocin
pancreas
parathormone
parathyroid glands
pituitary gland
progesterone
prolactin
prostaglandins
TSH
target organ cells
testes

15. Endocrine System Terminology
testosterone
thymus
thyroid gland
thyroxine
vasopressin
Disorders and Related Terminology
acromegaly
diabetes mellitus
dwarfism
gigantism
goiter
hyperglycemia
hyperthyroidism
hypoglycemia
hypothyroidism
tetany

17. Endocrine System ENDOCRINE GLANDS
Secrete hormones directly into bloodstream
Ductless
EXOCRINE GLANDS – secrete substances through a duct (sweat, salivary, lacrimal and pancreas)
Function of the Endocrine System – to secrete hormones – chemical messengers that coordinate and direct target cells and organs.

18. Endocrine System Hormonal Control NEGATIVE FEEDBACK
Drop in hormone level triggers a chain reaction to increase secretion, for example
Blood level of hormone falls
Brain gets message and sends out hormone to stimulate gland
Gland stimulates more hormone
When blood levels of hormone increase, the brain hormones stop
Nervous Control – in some cases, sympathetic nervous system causes direct release of hormone from gland (for example, when stress causes the adrenal medulla to secrete adrenalin)

19. Endocrine System PITUITARY GLAND Tiny structure the size of a grape
Located at the base of the brain
Connected to the hypothalamus
Divided into anterior and posterior lobes
The “Master Gland”

20. Endocrine System Anterior Pituitary Lobe
GROWTH HORMONE - GH (SOMATOTROPIN) responsible for growth and development
PROLACTIN – develops breast tissue, stimulates production of milk after childbirth
THYROID-STIMULATING HORMONE – TSH - stimulates thyroxine
ADRENOCORTICOTROPIC HORMONE – ACTH – stimulates adrenal cortex
FOLLICLE-STIMULATING HORMONE – FSH -stimulates growth of graafian follicle and production of estrogen in females, sperm in males
LUTEINIZING HORMONE – LH – stimulates ovulation and formation of corpus luteum, which produces progesterone in females

22. Endocrine System Posterior Pituitary Lobe
VASOPRESSIN – converts to ADH (antidiuretic hormone) in the bloodstream, acts on kidney to concentrate urine and preserve H2O in the body
OXYTOCIN – released during childbirth causing contractions of the uterus

23. Endocrine System THYROID GLAND Butterfly-shaped mass of tissue
On either side of larynx, over trachea
H-shaped
Main hormone – THYROXINE – is controlled by the secretion of TSH
Thyroxine controls the rate of metabolism
CALCITONIN – controls calcium ion concentration in the body, prevents hypercalcemia

25. Endocrine System PARATHYROID GLANDS
Four glands, each the size of a grain of rice
Attached to posterior thyroid
Produce PARATHORMONE which helps control blood calcium level, prevents hypocalcemia

26. Endocrine System THYMUS Endocrine gland and lymphatic organ
Located behind the sternum, above and in front of the heart
Begins to disappear at puberty

28. Endocrine System ADRENAL GLANDS Located on top of each kidney
Adrenal cortex secretes hormones known at corticoids – they are anti-inflammatory
They are: mineralcorticoids, glucocorticoids, and sex hormones
ANDROGENS are male sex hormones
Adrenal medulla secretes epinephrine (adrenalin) and norepinephrine
ADRENALIN is a powerful cardiac stimulent – “fight or flight” hormones that prepare the body for an emergency situation

30. Endocrine System GONADS Ovary in female Testes in male
Estrogen – development of female reproductive organs, secondary sex characteristics
Progesterone – plays a part in the menstrual cycle
Testosterone – male reproductive organs and secondary sex characteristics

32. Endocrine System PANCREAS Located behind the stomach
Endocrine and exocrine functions
Involved in production of INSULIN by ISLETS OF LANGERHANS
Insulin – promotes utilization of glucose by the cells, fatty acid and amino acid transport, and facilitates protein synthesis

34. Endocrine System Other Hormones
PROSTAGLANDINS – tissue hormones, can cause constriction of blood vessels, muscle contractions. Can be used to induce labor.

35. Endocrine System

36. Endocrine Disorders GIGANTISM
Hyperfunction of pituitary – too much growth hormone
In preadolescent – overgrowth of long bones leads to excessive tallness

37. Endocrine Disorders ACROMEGALY
Hyperfunction of pituitary – too much growth hormone in adulthood
Overdevelopment of bones in face, hands and feet
Attacks cartilage – so the chin protrudes, lips nose and extremities enlarge
Rx – drugs to inhibit growth hormone, radiation

38. Endocrine Disorders DWARFISM Hypofunction of pituitary in childhood
Small size, but body proportions and intellect are normal
Sexual immaturity
Rx – early diagnosis, injection of growth hormone

39. Endocrine Disorders HYPERTHYROIDISM Overactive thyroid gland
Too much thyroxine secreted leading to enlargement of gland
People with this disease consume large quantities of food but lose body fat and weight
Most pronounced symptoms are enlargement of gland (GOITER) and bulging of eyeballs (EXOPHTHALMOS)
Rx – total or partial removal of thyroid gland, drugs to reduce thyroxine, radiation

41. Endocrine Disorders HYPOTHYROIDISM Not enough thyroxine secreted
May be due to lack of iodine (simple goiter)
Major cause of other types is inflammation of thyroid which destroys the ability of the gland to make thyroxine
Symps – dry and itchy skin, dry and brittle hair, constipation, muscle cramps at night

43. Endocrine Disorders TETANY
In hypoparathyroidism, decreased calcium levels affect function of nerves
Convulsive twitching develops, person dies of spasms in the respiratory muscles
Rx – Vitamin D, calcium and parathormone

45. Endocrine Disorders DIABETES MELLITUS Caused by  secretion of insulin
Can be insulin dependent (juvenile) or non-insulin dependent
Symptoms – polyuria, polyphagia, polydipsia, weight loss, blurred vision, and possible diabetic coma
If not treated, excess glucose in blood (hyperglycemia) and glucose secreted in urine (glycosuria)
Since glucose not available for cellular oxidation, body starts to burn up protein and fat

46. Endocrine Disorders
If too much insulin is given, blood sugar may go too low (hypogycemia  insulin shock)
If blood sugar gets too high – hyperglycemia  diabetic coma
Type II (non-insulin dependent) is most common, usually familial, occurs later in life, control with oral hypoglycemic drugs and diet
Tests for Diabetes – blood sample measured in glucometer – done by patient in home – normal blood sugar mg

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