endo Flashcards
The main differences between H and neural systems
nervous: fast, precise, short duration, external environement imput
endocrince: slow, generalized, long duration, internal env imput
The 3 classes of H, and for each class, their solubility, synthesis and transport
peptides
solubility- hydrophilic
synthesis - produced like proteins
transport- free in plasma or bound to carrier protein
amines
solubility -hydrophilic
synthesis- derives from tyrosine
transport- plasma proteins
steroids
solubility- hydrophobic
synthesis- cholesterol precursor
transport- plasma proteins
*How are hormone levels regulated?
hormone effects are proportional to their concentration.
neg feedback
Rate of secretion into blood
2. Rate of metabolic activation
3. Extent of protein binding
4. Rate of removal from circulation
5. Number of receptors on target cell
The role of pineal gland
Pineal gland:
- Control circadian rhythm (day/night)
secretes melatonin
- Function of ADH and oxytocin
ADH: enhances retention of water by kidneys
oxytocin:*Stimulates contraction of uterine smooth muscles during birth
The H secreted by the anterior pituitary- How they get controlled from the hypothalamus-
Hypothalamus produces tropic H that control the release of H from the
anterior pituitary
several different tropic hormones
ex TSH, GnRH, CRH,
The vascular connection between hypothaland ant. Pit
Hypothalamo-hypophyseal portal system
heart to artery, capillaries in hypothal. (picks up Hormone) veins to capillaries in anterior pituitary (drops off H, picks up new H from pit.) veins – heart.
Name 3 factors, beside GH, affecting growth
nutrition, genetics, sleep, physical activity
. *What are the metabolic effects of GH? *
Overall effect: mobilize fat stores as major energy source, keep glucose for the brain (brain can’t
use fatty acids
increase fat breakdown
*What are the differences between IGF1 and IGF2?
IGF1 : the most important IGF for growth.
* Stimulated by GH
* Produced everywhere (mostly for local – paracrine – effects),
liver secretes IGF1
IGF2: does not need GH
for fetal development
produced continuously throughout life for muscle growth
fucntion of aplha beta and delta pancreads cells
- Alpha cells: Produce glucagon, a hormone that raises blood glucose levels by stimulating glycogen breakdown and gluconeogenesis in the liver.
- Beta cells: Produce insulin, a hormone that lowers blood glucose levels by promoting the uptake of glucose into cells and the storage of glycogen in the liver.
- Delta cells: Produce somatostatin, a hormone that inhibits the release of both insulin and glucagon, helping regulate the balance between these hormones.
What steps are involved in the elongation of long bones?
Gets signal. Starts mitosis.
Chondrocytes replicate.
Bone gets longer
Initially, chondrocytes (cartilage cells) form the cartilage model.
Over time, osteoblasts begin to replace the cartilage with bone tissue, first by laying down a bone matrix and eventually turning the cartilage into mineralized bone.
over time, osteoclasts use Hcl and enzymes to breakdown bone while osteroblasts are producing bone which allows for a full cell turnover
How are GH regulated?
2 hormones
GHIH
GHRH
and neg feedback
What conditions are associated with a lack of GH?
if before birth: dwarfism
if after birth: Reduced muscle mass and bone mass, increased fat
*What conditions are associated with an excess of GH?
children: gigantism
adult: acromegaly
*What test are used to diagnose GH deficiency disorder?
insulin tolerance test
*What test are used to diagnose GH excess disorder?
glucose suppression test
:The location and structure of the thyroid gland
The thyroid gland is located in the neck, It consists of two lobes
how TH is synthesized in the thyroid gland
need iodide and tyrosine
steps in notes
How TH is transported-
over 99% transported bound to plasma protein
lipophilic. travels through membranes
The effects of TH:
metabolic
cardiovascular
growth and NS
dermallogical
metabolic effects: high TH: catabolic- protein fat and glucose breakdown
cardiovascualar: TH increases heart responsiveness to catecholamines
growth and NS: TH essential for growth. GH needs TH. TH needed for normal NS function
demalogical effects: Too much or too little TH causes hair loss
The regulation of TH
main regulator..
main regulator.. TSH
*What are the 3 main categories of steroids produced, and what is their main functions?
mineralcorticoids- aldosterone (na/K) blance
glucorticoids- cortisol- glucose metabolism
sex hormones- sex characteristics
? *What are the metabolic, anti-inflammatory and immunosuppressive effects of GC?
Glucocorticoids (GC) have
metabolic effects such as increasing glucose production and mobilizing fats and proteins;
anti-inflammatory effects by inhibiting the production of pro-inflammatory cytokines and immune cells; and immunosuppressive effects by reducing the activity of immune cells, especially T-cells and macrophages.
What are the negative impacts of GC use?
increase chance of infection, increase fat and protein breakdown, HPA axis supression
. *What can’t you stop GC suddenly?
when stopping Glucocortisoids suddenly the ant pit remains supressed and does produce ACTH and tf to cortisol is produced. . Without cortisol, the body would have difficulty responding to stress, regulating metabolism, maintaining blood pressure, and balancing immune responses
? *What are the symptoms, causes and cures of a lack of steroid production?
symptoms like fatigue, muscle weakness, weight loss, low blood pressure, low aldosterone
The causes are often autoimmune destruction of the adrenal glands or pituitary dysfunction, and treatment typically involves lifetime hormone replacement
