endocrine 1.3

Question 1

3 ways of hormone secretion to endocrine cell

Answer 1

1. changes in the plasma concentrations of mineral ions or organic nutrients
2. neurotransmitter released from neurons ending on the endocrine cell
3. another hormone acting on endocrine cell

can have excitatory or inhibitory action

push and pull on how much is getting released

Question 2

negative feedback control via secretion of mineral ions or organic nutrients

Answer 2

• increase plasma glucose concentration
• increase insulin secretion
• plasma insulin increases
• insulins target cells increase actions of insulin

results in negative feedback to decrease glucose concentration

Question 3

control by neurons

Answer 3

parasympathetic and sympathetic system both have inputs

endocrine gland and anterior pituitary gland can have stimulatory or inhibitory response

**review slides

Question 4

control by other hormones

Answer 4

• a particular hormone is directly controlled by the blood concentration of another hormone
• referred to as “tropic hormone”
• can be stimulatory or an inhibitory action

first hormone has a sequence to stimulate or inhibit the second hormone

depending on how much the gland is secreting, too much or too little there is different types of endocrine disorders

Question 5

endocrine disorders

Answer 5

• imbalance in metabolism → loss or gain of weight
• failure to grow or develop normally in early life
• mental and emotional changes
• abnormally high or low BP
• loss of reproductive fertility

Question 6

endocrine disorder categories

Answer 6

hyposecretion : too little secretion

hypersecretion ; too much secretion

hyporesponsiveness : decrease responsiveness of the target cells to that hormone

hyperresponsiveness : increase responsiveness of the target cells to that hormone

Question 7

hyposecretion 2 kinds

Answer 7

primary hyposecretion and secondary hyposecretion

Question 8

primary hyposecretion

Answer 8

occurs due to :

1. primary destruction of a gland
2. enzyme deficiency (result in decrease synthesis of that hormone)
3. deficiency of iodine

Question 9

secondary hyposecretion

Answer 9

occurs due to tropic hormone being synthesized and released at an abnormally low rate

• can be reversed if concentration of tropic hormone increased
• leads to atrophy of the target gland (because lack of stimulation from tropic hormone)

Question 10

how do u distinguish primary from secondary

Answer 10

measure the concentration of tropic hormone level in the blood and if its at normal levels then we know its primary

Question 11

treatment for hyposecretion

Answer 11

administer the missing hormone or a synthetic analog of the hormone

topical creams, nasal spray or injections

Question 12

HPA axis Hypothalamus-pituitary - adrenal

Answer 12

For when we have hypo secretion

• stress leads to hypothalamus releasing CRH
• Acts on anterior pituitary which is going to release ACTH
• ACTH goes to the adrenal gland to secrete cortisol
• once cortisol is in the blood it has a negative feedback effect on the anterior pituitary to stop release of ACTH and also negative feedback to the hypothalamus to stop the release of CRH

Question 13

addisons disease

Answer 13

loss of negative feedback by ACTH

• form of hypocortisolism leading to lower cortisol production and high levels of ACTH
• causes : autoimmune disease, adrenal cancers
• symptom : when we break down ACTH it results in increased pigmentation (tan)

Question 14

hypersecretion 2 kinds

Answer 14

primary hypersecretion and secondary hypersecretion

Question 15

primary hypersecretion

Answer 15

gland is secreting too much of the hormone

-can be due to presence of a hormone secreting or an endocrine tumor which produce the hormone at high rates even if not stimulation, or increase negative feedback loops

Question 16

secondary hypersecretion

Answer 16

excessive stimulation of the gland by its tropic hormone

can be due to hormone secreting or endocrine tumor

Question 17

treatment for hypersecretion

Answer 17

remove tumor surgically or destroy by radiation

• drugs that inhibit hormone synthesis and block hypersecretion
• drugs that block the receptors for hormone to attach to

Question 18

cushings disease/syndrome

Answer 18

hypercortisolism based on tumor of the adrenal gland or too much glucocorticoids

• fat deposition of face, back, central abdomen
• redistribution of fat so arms and legs are thin
• loose skin with striae
• osteopenia/osteoporosis

-immune suppression (cortisol suppresses immune pro inflammatory cytokines which is why we get sick more when stressed)

Question 19

hyporesponsiveness

Answer 19

component of endocrine system may not be functioning normally, even though there is nothing wrong with the hormone secretion

1. target cells do not respond normally to the hormone, or hormone resistance
   - result from deficiency or loss of function of receptors for the hormone
2. signaling even that occurs within the cell after the hormone binds to its receptors may be defective (no secondary messengers)
3. deficiency of the enzyme that catalyze the activation

Question 20

hyperresponsiveness

Answer 20

eg. thyroid hormone causes up regulation of beta adrenergic receptors for epinephrine
- resulting in hyper responsiveness to a target cell for epinephrine
- results in increase HR in people with increased plasma concentration of thyroid hormone