endocrine system Flashcards
What is homeostasis?
A state of overall internal chemical and physical stability that is required for the survival of cells and the body
What do homeostatic mechanisms do?
Maintain a constant internal environment despite a variable external environment
What does deviation from homeostasis indicate?
Disease
What is a set point?
The physiological value around which the normal range fluctuates
What is a negative feedback loop?
A feedback loop where the the effect opposes the original stimulus
What are the elements of a feedback loop
Stimulus, receptor, integrator, effector, response
What is positive feedback?
Where the response increases the original stimulus
Pathway of steroids hormones
lipid soluble - diffuse directly through the cell membrane
enter the cytoplasm
enter the nucleus
form a hormone receptor complex (transcription factor)
binds to promoter regions of genes
stimulates or inhibits the transcription of those genes
What are the two types of hormones?
Lipid hormones
Non lipid hormones, peptides
Pathway of peptide hormones
binds to a receptor on the cell membrane
- activates a Secondary messenger
Paracrine
Hormone stimulates a nearby cell, travels through extra cellular material
Autocrine
The hormone secretion acts on the cell itself or cell type
Which hormones does the anterior pituitary secrete?
ACTH, TSG, FSH, LH, GH, prolactin
Which hormones does the posterior pituitary produce?
ADH, oxytocin
What does the adrenal cortex secrete
Cortisol, aldosterone, sex hormones
What does the adrenal medulla secrete?
Adrenaline and noradrenaline
What do the ovaries and testes secrete?
the ovaries secrete estrogens, progesterone, inhibin, and androgens
estes primarily secrete testosterone and inhibin.
What does the pineal gland secrete?
melatonin,
What does the thyroid secrete?
thyroxine (T4) and triiodothyronine (T3), which regulate metabolism and energy use, as well as calcitonin
What does thyroid hormone do?
are vital for regulating metabolism
growth
development
cardiovascular function
temperature regulation,
lipid metabolism
reproductive health.
What does calcitonin do?
helps lower blood calcium levels by inhibiting osteoclast activity in the bones and promoting the excretion of calcium by the kidneys
What do the parathyroid glands secrete?
secrete parathyroid hormone (PTH)
What does parathyroid hormone do
essential for maintaining calcium homeostasis in the body
- increases blood calcium levels by stimulating bone resorption
- enhancing renal calcium reabsorption
- promoting phosphate excretion
- activating vitamin D
What are normal blood glucose levels?
between 70 and 99 mg/dL
What is the exocrine function of the pancreas?
it produces digestive enzymes (amylase, proteases, and lipase)
- bicarbonate secreted into the small intestine
- substances facilitate the breakdown of carbohydrates, proteins, and fats
What is hypothyroidism?
insufficient production of thyroid hormones
What is hyperthyroidism?
excessive production of thyroid hormones
What are symptoms of hypothyroidism?
increased metabolism and a range of symptoms, including weight loss, rapid heart rate, anxiety, and heat intolerance.
What are the symptoms of hyperthyroidism?
increased heart rate, weight loss, nervousness, tremors, heat intolerance, fatigue, and changes in menstrual patterns
What is pituitary dwarfism?
condition caused by insufficient growth hormone production from the pituitary gland
What happens to effective circulating blood volume and blood pressure when someone is bleeding internally?
internal bleeding causes a decrease in effective circulating blood volume due to the loss of blood. Initially, the body compensates for this loss, but if bleeding persists, blood pressure will ultimately decrease
Effect of adrenaline on sweat glands and blood vessels of the skin
adrenaline increases sweating by stimulating sweat glands, particularly in response to emotional stress, while simultaneously causing vasoconstriction of blood vessels
What is hypovolemic shock?
hypovolemic shock is a critical condition resulting from a significant decrease in blood volume,
What are some symptoms of hypovolemic shock?
Nausea or Vomiting
Fatigue or Weakness
Thirst
Rapid Breathing (Tachypnea)
Confusion or Altered Mental Status
What happens to cells if there is insufficient insulin in a diabetic?
insufficient insulin in a diabetic leads to impaired glucose uptake by cells, resulting in high blood sugar levels and compensatory breakdown of fat and protein for energy.
What is a byproduct of the breakdown of fat?
the primary byproducts of fat breakdown are free fatty acids and glycerol, while ketone bodies can also be produced under specific metabolic conditions
What happens when ketones build up in the blood?
ccumulation can lead to ketoacidosis, a serious condition characterized by metabolic acidosis, dehydration, and a range of distressing symptoms
