Chapter 23 Flashcards
Where are the receptors for the hormones in the endocrine system found?
The plasma membrane, cytosol and the nucleus
What are some of the responses that can occur as a result of a hormone binding to its target?
Increased cell signaling and increased gene expression
How can the target response of a hormone be altered?
by the amount of the hormone that is released and by the number of receptors
What can cause pathologies in the endocrine system?
Hypersecretion, hyposecretion, and abnormal target cell responses
What are the layers of the adrenal gland? Going from superficial to deep
Capsule
Cortex
Medulla
What branch of the PNS is the adrenal medulla a part of?
Sympathetic branch
What does the adrenal medulla release and what does it do?
It secretes epinephrine and mobilizes fuel sources
What are the layers of the adrenal cortex going from superficial to deep?
Zona glomerulosa
Zona fasciculata
Zona reticularis
What do all the hormones made in the adrenal cortex have in common?
That they are all derived from cholesterol and are chemically similar to each other
What is uniquely produced in each zone of the adrenal medulla that makes the hormones from each zone distinct?
that each zone produces different enzymes which form different hormones
If the hormones from the adrenal medulla are all similar, do they have their own receptors or if not, how does that work?
In some cases they do bind to the same receptor but, if the wrong steroid tries to bind to a receptor intercellular enzymes tend to take care of it
What kind of hormones does the zona glomerulosa produce? What is the main one?
It produces mineralocorticoids with aldosterone
What is the effect of aldosterone in the body?
It regulates sodium and potassium which in turn regulates electrolytes
What kinds of hormones does the zona fasciculata produce? What is the main one?
It produces glucocorticoids with the main one being cortisol
What is the effect of cortisol in the body?
It regulates glucose levels by increasing glucose in when we are faced with stress
What does the zona reticularis produce? What are the main ones?
glucocorticoids- cortisol
What is important about the androgens that are released from the Zona reticularis in males and females?
That androgens get converted to whatever would be the opposite for the person’s sex for example women the androgen will be the one source of androgen and for men it will be the one source of estrogen
What causes/ stimulates the secretion of CRH from the hypothalamus?
The circadian rhythm which increases in the morning and stress in general
What does CRH cause to be secreted from the anterior pituitary and where does it go to?
ACTH and it goes to the adrenal cortex
What does the adrenal cortex release as a result? And from what layer of the cortex does it come from?
It releases cortisol from the zona golmerulosa
What are the targets for cortisol?
any cell with a nucleus meaning it can have a wide range of effects on the body
What are the four main targets of cortisol?
-Immune system
- liver
- muscle
- adipose tissue
What is the effect of cortisol on the the liver, muscle, and adipose tissue?
To increase blood glucose
What is the effect of cortisol on the immune system?
To inhibit the immune system
What is lipolysis of adipose tissue? And what is it caused by?
It is the breakdown of the adipose tissue that is caused by cortisol so the fats can get sent to liver to get converted into glucose
What is the effect of cortisol on the catecholamines?
A permissive and a synergistic effect
What are catecholamines?
Nornepinephrine and epinephrine
What is the affect of cortisol on glucagon?
it has a permissive effect and accelerates gluconeogenesis
What is the result of cortisol on catecholamines?
That blood vessels are more sensitive to vasoconstriction
Where does gluconeogenesis happen?
In the liver
What is gluconeogeneisis?
It is when the liver breaks down other molecules such as fats and amino acids to break them down into glucose
What is the effect of cortisol in the muscle?
Protein catabolism
What happens in protein catabolism?
It is when the muscle breaks down to create amino acids so the liver can use them to convert into glucose
What is the effect of cortisol on adipose tissue?
Lipolysis
What is lipolysis?
It is breakdown of adipose or fats to get used by the liver to convert into glucose
Cortisol is essential to live because it protects against ______________________
hypoglycemia (low blood glucose)
What is the effect of cortisol on the immune system?
It inhibits the immune response because it takes energy for the immune system to function and to fight stressors the energy should be used for more immidiate or short term stressors
What kind of immune cell does cortisol inhibit?
White blood cells
What are cytokines? and what happens to them?
They are communication cells of the immune system that get inhibited by cortisol
Cortisol also stops the formation of what in the immune system?
antibody (protein) synthesis
Exogenous (outside of the body) cortisol is use to treat what kinds of conditions?
allergic reactions
arthritis
organ transplantation
What would the effects of high does of exogenous (outside of the body) cortisol have on CRH and ACTH if it is used for extended periods of time?
Their levels would be significantly reduced or in some cases stopped completely due to the adrenal gland breaking down and no longer able to respond to ACTH
What is hypercortisolism?
It is a excessive secrection of cortisol
What would the effects of hypercortisolism be on blood glucose levels? And what other condition does this symptom get mistaken for?
It would be high and it gets mistaken for type 2 diabetes for this reason
What would be the effect of hypercortisolism on skeletal muscle?
It would be smaller because more cortisol would mean that it is getting broken down at a higher rate
What would be the effect of hypercortsolism on adipose tissue?
Adipose gets broken down in the limbs but the fat gets abnormally deposited in the face and neck
What happens to appitite with hypercortisolism?
Your appititie increases by a lot
What are the potential causes for hypercortisolism? and what pathologies are they? and what is most common?
Cushing’s syndrome (most common)
adrenal tumor (primary)
pituitary tumor (secondary)
cortisol therapy
What is adrenogenital syndrome (AGS)?
It is the hypersecretion of androgens
What are the effects of hypersecretion of androgens?
- enlarged sex organs in children
-the early onset of puberty
What can happen in prenatal AGS?
someone who is chromosomally female could have male genitalia as a result of a hypersecretion of androgens
Where is the thyroid gland located?
At the base of the neck just below the larynx
What do the c- cells in the thyroid gland release?
Calcitonin
What does calcitonin do?
It regulates blood calcium
What are follicular cells made up of?
follicles
What do the follicles in the follicular cells produce?
thyroglobulin which is located in the follicles
What does thyroglobulin get converted into?
It gets converted into thyroid hormones
What is colloid?
It is the fluid that is located inside of the follicles
What are the two kinds of thyroid hormones? Which one is most active and which one is most abudant?
T3 (most active)
T4 (most abundant)
What molecule is needed in order to produce thyroid hormones?
Iodine and each kind of thyroid hormone requires a different one
What can iodine deficiency cause?
A goiter because the TSH from the anterior pituitary will keep trying to stimulate the thyroid hormone which increases the amount of thyroglobulin in the which ends up build up as fluid producing a goiter
What is the stimulus that causes the thyroid hormones to be released? And where does it come from?
Thyroid stimulating hormone which comes from the anterior pituitary
What is the target of the thyroid hormones?
Most cells in the body respond to the release of it
What are the effects to the thyroid hormone?
- increased metabolism of all macronutrients
- promotes growth hormone expression in children
-increased O2 consumption - promotes brain development
- increased heat production
How is thyroid hormone stimulation regulated?
through negative feedback the more thyroid hormones that are found in the blood, the less TRH and TSH will be released from the hypothalamus and anterior pituitary
What are the effects of hyposecretion from the thyroid gland?
- low metabolic rate
-slugishness
-sleepiness - weight gain
- constipation
- dry skin and hair
endemic goiter or enlargement of thyroid gland
What are the effects of hyperthyroidism?
- weight loss
- tremors
- nervousness
- bulging eyes
toxic goiter
A deficiency of the thyroid gland can cause a _______ goiter
endemic
What is graves disease? Is its effects similar to hyper or hypo thyroidism?
it is an autoimmune condition where the immune system produces antibodies that mimic TSH so the thyroid gland gets stimulated when it shouldn’t be and can cause a toxic goiter
Hyperthyroidism
What what are the things that cause for the Growth Hormone to be released?
Circadian Rhythm
Normals levels of stress
Intermittent fasting
Ghrelin
What are the hormones that affect growth?
- growth hormone GRH
- T3 and T4
- insulin
- sex steroids
What is needed nutritionally to promote growth?
- protein
- enough calories
- vitamins and minerals
What environmentally is needed to promote growth?
absence of chronic stress because too much cortisol inhibits growth
_____% of height is determined by genetics
80
What is the stimulus for GH or growth hormone to be released?
Growth Hormone Releasing Hormone (GHRH) from the hypothalamus to the anterior pituitary
Is growth hormone a trophic or non trophic hormone?
It’s both
What is release of Growth Hormone (GH) stimulated by?
Circadian rhythms- GH is released the most during sleep onset
Stress/ Cortisol- is needed for growth but too much will inhibit it
intermittent fasting- puts your body into a fasted state and stimulates growth hormone release
ghrelin- hunger hormone from the stomach puts body into a fasted state
What causes Growth Hormone Inhibiting Hormone (GHIH) or somatostatin to be released?
The presence of growth hormone and insulin like growth factors in the blood
What are the targets of Growth Hormone?
The liver to release insulin like growth factors and directly onto cells in the liver, muscle, and bone to increase blood glucose
Growth hormone stimulates ( what type of cell division)
mitosis
What do the insulin like growth factors (IGF) stimulate on its own?
growth of cartilage
What do GH and IGF together stimulate?
protein synthesis and bone growth
What condition does hyposecretion of growth hormone cause?
It can cause dwarfism (not the genetic kind)
What are the physical effects of pituitary dwarfism?
The person will be short but unlike in genetic dwarfism their limbs and their torso will be proportional
What are the conditions that can be caused by hypersecretion of growth hormone?
Gigantism and Acromegaly
What are the physical effects of gigantism?
It refers to a lot growth before the growth plates have closed but it can sometimes cause people to pass away at a young age because their heart can’t keep up with their body
What are the physical effects of Arcomegaly?
it refers to growth after the growth plates have closed but they are still growing. So that means that their muscles or torso area will still grow and lots of muscle tissue
What are the two kinds of bone tissue that are present in bone?
Compact bone and spongy
What kind of tissue is bone made out of? And what does it contain besides just the cells of the bone itself?
It’s made out of connective tissue and it also contains matrix and bone cells
At what part of the bone does growth occur in the long bones?
At the metaphysis which is between the epiphysis and diaphysis
What are the two major components that make up the matrix of the bone tissue?
The hydroxyapatite crystals and the collagen fibers
What is the role of the hydroxyapatite crystals? and how much of the bone does it make up?
To provide strength and the hardness of the bone and it makes up 2/3 of the bone mass
What is hydroxyapatite crystal made out of?
lots of calcium salts
What is the role of collagen fibers and how much of total bone mass do they make up?
to allow for flexibility/ tolerate disotortion and they make 1/3 of bone mass
What kinds of cells are in bone?
osteogenic cells, osteoblasts, osteocytes, and osteoclasts
What is the role of osteogenic cells in bone?
It is the stem cell that produces osteoblasts
What does deposition of bone mean?
The building of bone
What does the resorption of bone mean?
The breaking down of bone
What is a osteoblast? And what does it do?
It is a immature bone cell that makes collagen fibers for the matrix. which eventually become encrusted with minerals
What is an osteocyte? What does it do?
It is a mature osteoblast that is stuck since all of the collagen has been encrusted with minerals and helps maintain the matrix
What are osteoclasts? And what do they do?
They descend from macrophages and release enzymes that breakdown bone
How does a calcium deficiecy affect bone strength?
It weakens the bones because the bones will break down to release calcium into the blood to maintain proper levels
How does long bone growth occur?
As the cartilage cells divide along the epiphyseal plates bone will grow in its place
Why is cartilage not as hard as bone?
Because it does not have the deposition of calcium salts
As long as the pace of ____________ growth is out pacing ____________ growth then bone growth is still happening
cartilage, bone
When does growth of the long bones end?
It’s when the bone growth outpaces the cartilage growth and the growth plate just becomes a line of bone
What forms the epiphyseal plate?
When the long bone stops growing and it is just a line in the epiphysis part of the bone
Do the plates tend to stop sooner for males or females? And when?
Females in their mid to late teens and males in their late teens early 20s
What hormone is required for cartilage growth?
IGF (insulin like growth factors)
What are the hormones that effect bone growth?
GH
IGF
Androgens- stimulate long bone growth and since males have more they tend to be taller
Estrogen- closes the plates in both sexes and affects mineral density
How does mechanical stress affect long bone growth?
It is needed in order to help build and maintain bone
How can an inactive kid affect their bone growth?
They might not grow as tall due to lack of physical activity
Is excercise necessary for maintaining bone health in adults? And what kind specifically?
Yes, it can help strenghten it specifically high impact exercise
What bodily functions is calcium essential for?
exocytosis of neurotransmitters
muscle contractions
needed for enzyme activity to occur
contributes to tight junctions
helps in blood clotting
What ae some non dairy product sources of calcium?
Vegetables, figs, nuts and seeds
How important is calcium levels in the blood? What is it prioritized over?
It is very important and in dire cases it is prioritized over bone density/health as calcium will be taken from the bones to go into the bloodstream
What is the from of calcium output from the body? What organ does it take place in?
Through the urine starting in the kidneys
What are the methods of calcium intake?
Paracellularly from the intestines into the blood
Hormone induced transcellular route which is where the Ca2+ is moved by the cells lining the intestine
What is it called when the calcium saved by the kidneys?
reabsorbtion
How is calcium regulated by the bones?
Based on if it does deposition which moves Ca2+ into the bones for bone construction or if does resorption which breaking down bone and releasing calcium
What are the 3 organs that keep Ca2+ in balance?
Intestines, kidneys, and bone
What are the 3 hormones that regulate calcium?
Parathyroid hormone
Calcitriol
Calcitonin
Which 2 hormones increase absorption of calcium?
Parathyroid hormone (PTH)
Calcitriol
Which hormone decreases absorption?
Calcitonin
Which organ(s) does PTH and Calcitriol effect? And what are those effects?
small intestine - increases absorption
bone- increased bone absorption
kidneys- increase reabsorption
Which organ(s) does calcitonin effect? And what are the effects?
Bone- decreases bone absorption
Kidneys- increased secretion
What are the two major cell types of the parathyroid glands?
Parathyroid (principal) cells secrete PTH
Oxyphil have an unknown effect
What are the 2 ways calcitriol gets stimulated?
It can get stimulated through sunlight/vitamin or diet absorption D that causes the liver to turn it into an intermediate that stimulates the kidney to stimulate calcitriol
Or a decrease in blood plasma will cause the parathyroid hormones to stimulate the kidney to produce calcitriol
What else in the body is effected by vitamin D?
immune system
cardiovascular
the brain
What causes osteoporosis in the elderly?
Resorption of the bone outpaces deposition of the bone as people age
A drop in what hormone can increase the likelyhood of ostroporosis?
Low estrogen levels which gradually decrease with age
How does menopause affect the onset of osteoperosis?
After menopause women experience a large drop in estrogen levels which increases the chances of developing it
At what age do men see an increased risk of developing osteoporosis?
men over the age of 65
What can help prevent osteoporosis?
Height and weight bearing excercise
Growth hormone promotes what kind of growth?
bone growth
