Endocrine & Hematology Flashcards
Gene activation of steroid based hormones:
- steroid hormone diffuses through plasma membrane & binds an intracellular receptor
- the receptor hormone complex enters the nucleus
- receptor hormone complex binds to specific DNA region
- binding initiated transcription of mRNA
- mRNA directs protein synthesis
Gene activation of amino acid-based hormones:
- hormone (1st messenger) binds a receptor
- Receptor activates G protein
- G protein activates adenylate cyclase
- adenylate cyclase converts ATP to cAMP (2nd messenger)
- cAMP activates protein kinases
thyroid gland:
- major metabolic hormone
- amino acid based hormones, yet lipid soluble
- T4 (most used in the body) = 2 tyrosine + 4 iodine
- T3 = 2 tyrosine + 3 iodine
posterior pituitary lobe:
- aka neurohypophysis
- secretes amino acid based hormones: oxytocin & antidiuretic hormone
- infundibulum > infundibular stalk > pars nervosa
oxytocin:
- posterior pituitary hormone
- stimulates uterine contractions (positive feedback loop) & milk ejection
- also for affection & bonding
uses PIP2-calcium second messenger system
antidiuretic hormone (ADH):
- posterior pituitary hormone
- osmoreceptors
- targets kidneys to reabsord water & prevent urine output
- inhibited by diuretics & alcohol
anterior pituitary lobe:
- aka adenohypophysis
- secretes peptide hormones
- all but growth hormone (GH) activate cells via cAMP
- all but GH and prolactin are tropic
- pars tuberalis > pars distalis
- pars intermedia (between anterior & posterior pituitary lobes)
growth hormone (GH):
- aka somatropin
- directly acts on metabolism = triggers breakdown of glycogen
- indirectly acts on growth = triggers liver to produce insulin-like growth factors (IGF)
thyroid stimulating hormone (TSH):
- activated by thyrotropin-releasing hormone (TRH)
- stimulates secretion of T4
adrenocorticotropic hormone (ACTH):
- stimulates adrenal glands to release cortisol
- anterior pituitary hormone
follicle stimulating hormone (FSH):
- gonadotropins
- target ovaries & testes
- cause secretion of steroid sex hormones
luteinizing hormone (LH):
- controls menstrual cycle & release of egg from ovaries
- stimulates testes to make testosterone
prolactin (PRL):
- stimulates milk production
pancreas hormones:
- insulin = lowers blood glucose & opens glucose transporter
- glucagon = raises blood glucose
adrenal gland components:
- zona glomerulosa = mineralocorticoids (salt)
- zona fasciculata = glucocorticoids (sugar)
- zona reticularis = gonadocorticoids (sex)
^^^ layers of the cortex
\/\/\/\/ under the cortex: - adrenal medulla = synthesize catecholamines (epinephrine & norepinephrine)
monocytes:
- largest WBCs
- kidney shaped nucleus
- for inflammation & viral infection
- once they are in tissues = become macrophages
lymphocytes:
- immune memory
- antibody secretion
- look like an eye ball kinda
eosinophils:
- 2 large lobes connected
- abundant in mucus membranes
- for allergies & parasites
basophils:
- rarest WBCs
- secrete histamine
neutrophils:
- don’t stain dark, 3-5 lobes
- respond to bacterial infection
- most common type of WBC
diabetes insipidus:
- huge output of dilute urine
- intense thirst
- may occur after head injury = damage to hypothalamic neurons that secrete ADH
diabetes mellitus:
- type 1: autoimmune; inability to produce insulin; treated with insulin injections
- type 2: most prevalent; insulin resistance; treated with diet & exercise
Pituitary dwarfism:
- hyposecretion of growth hormone
- abnormally short & some mental delays
Cushing’s syndrome:
- often caused by overtreatment w/ therapeutic steroids (ex: cortisone)
- Cushing’s Disease = ACTH secreting tumor
- symptoms: hypercalcemia, salt & water retention, fat redistribution, moon face, buffalo hump
- treatment: meds to control cortisol levels
hypothyroidism:
- deficiency in thyroid hormones
- in infants *extreme cases = cretinism
- symptoms = delays in mental & physical growth
- treatment = levothyroxine
liver hormones:
- insulin-like growth factors (IGF)
- angiotensinogen = blood pressure
- liver also stores glycogen for glyconeogenesis
hypothalamus-pituitary-thyroid axis:
1) thyrotropin-releasing hormone (TRH) travels from hypothalamus to hypophyseal portal system then to the anterior pituitary gland
2) thyroid stimulating hormone (TSH) stimulates secretion of T3 & T4
hypothalamus-pituitary-adrenal axis:
1) corticotropin-releasing hormone (CRH) travels from hypothalamus to hypophyseal portal system to anterior pituitary
2) CRH stimulates secretion of adrenocorticotropic hormone (ACTH)
3) ACTH stimulates secretion of gluco/mineralocorticoids
target cells for hormones:
- have specific receptors for specific hormones
where is insulin produced:
- beta cells in the pancreas
“master” endocrine gland:
- hypothalamus regulates neurohormones
iodine deficiency:
- hypothyroidism
- during pregnancy, may result in cretinism
glucagon:
- raises blood glucose levels
- used for glyconeogenesis (free glucose is released)
- produced in alpha cells of the pancreas
short-term stress hormones:
- adrenal medulla secretes catecholamines (epinephrine & norepinephrine
- fight or flight response
- raises BP, heart rate, & blood sugar
long-term stress hormones:
- adrenal cortex secretes corticosteroids
- glucocorticoids = prevent inflammation & increase blood sugar
- mineralocorticoids = aldosterone promotes sodium reabsorption in kidneys
B12 deficiency results in:
- pernicious anemia
- deficiency of intrinsic factor secretion
polyuria:
- occurs when blood glucose levels are high
- type 1 diabetes mellitus = excess glucose in urine pulls more water = more urine
- diabetes insipidus = damage to hypothalamic neurons that secrete ADH
hyperthyroidism:
- Grave’s disease = most common type
- goiter
- treated w/ removal of thyroid glands or radioactive iodine to destroy thyroid cells
hypothyroidism:
- iodine deficiency
- mental & physical impairment
- preventable & less prevalent due to iodized salt
what does aldosterone regulate:
- sodium homeostasis
erythrocytes:
- aka RBCs; cells that contribute to gas transport
- biconcave shape = huge surface area to relative volume (for gas transport)
- hemoglobin = makes up 97% of RBC
- no mitochondria; no ATP; glycolysis used to make energy = O2 transport efficient
- discoidal, anucleate, no organelles
- contains spectrin protein = flexibility
- not a complete cell
leukocytes:
- WBCs; complete formed cells
- defend against disease
- leap across/leave circulatory system via diapedesis
- attracted to infection site by chemotaxis
leukocytes in order from most prevalent to least prevalent:
- Neutrophils
- Leukocytes
- Monocytes
- Eosinophils
- Basophils
platelets:
- aka thrombocytes
- not true cells; cell fragments
- function to stop bleeding (clotting)
electrolytes in ICF, IF, & blood plasma:
- Intercellular fluid: K+ & A-
- Interstitial fluid: Na+ & Cl-
- blood plasma: Na+, Cl-, & A-
- IF = 80% of ECF
- blood plasma = 20% ECF
blood plasma composition:
- 90% water
- dissolved solute = glucose, amino acids, fatty acids
- O2, CO2, hormones, wastes
- inorganic ions (electrolytes) mostly Na+ and Cl-
- plasma proteins = globulins, fibrinogen (scab/clots), & albumin (60% of plasma proteins); carries molecules; acts as blood buffer & helps with osmotic pressure
stem cells maturation to RBCs:
- stem cells for RBCs come from red bone marrow (hemocytoblasts)
- stem cells = hemocytoblast
- develops into committed cell = proerythroblast
- phase 1 = ribosome synthesis
- phase 2 = hemoglobin synthesis & iron accumulation
- phase 3 = ejection of organelles & nuclei; cell collapses (biconcave)
- cell then becomes a reticulocyte (young erythrocyte)
- finally becomes erythrocyte
erythropoietin (EPO):
- amino acid based hormone that stimulates formation of RBCs
- causes committed cells to mature into RBCs more rapidly
- released by kidneys (some from liver) in response to hypoxia (low O2 in blood)
steps for formation of platelet plug:
- break/tear occurs in blood wall
- platelets deployed to injury site
- platelets adhere to site & release chemicals
- released chemicals attract more platelets
- platelet plug is formed
bone that protects pituitary gland:
sella turcica
composition of blood samples:
top to bottom:
- 47-63% plasma
- 1% WBCs & platelets
- 37-52% RBCs
neutrophil actions order:
1st to arrive at scene of injury
1. bacteria activate neutrophil
2. diapedesis = flatten & squeeze out of capillaries
3. chemotaxis = follow a chemical trail to the injury site
4. phagocytosis = ingestion of microbes
5. release oxidizing substances to destroy
electrolyte balance maintenance:
- aldosterone regulates Na+ and K+ in ECF
- stimulates kidneys to reabsorb more Na+ & water back into blood & secrete K+ in urine
1. hypothalamus contains corticotropin-releasing hormone (CRH)
2. anterior pituitary releases adrenocorticotropic hormone (ACTH) to adrenal cortex
3. this stimulates mineralocorticoids that tell the kidneys to retain Na+ & water
Hashimoto’s Disease:
- autoimmune disease
- antibodies attack thyroid gland
- prevents T3 & T4 synthesis
- symptoms = weight gain, fatigue, irritability
- treatment = levothyroxine
when is it best for a diabetic to take insulin:
- 15-30 minutes before a meal
GPA:
- Growth hormone & Prolactin = Acidophils
B-FLAT:
Basophils produce & secrete FSH, LH, ACTH, TSH
polycythemia:
- condition in which there are too many RBCs
- primary vera polycythemia = cancer of erythropoietic line of bone marrow (RBCs = 11 millions) (hematocrit = 80%)
- secondary polycythemia = dehydration or smoking (emphysema)
Grave’s Disease:
- most common type of hyperthyroidism
- autoimmune antibodies mimic TSH
- symptoms = protrusion of eyes (exophtalmos proptosis), goiter, rapid heart rate, muscle weakness
- treatment = removal of thyroid gland or radioactive iodine
hematocrit:
- actual volume of RBCs in blood
- low hematocrit = anemia
What does “tropic” hormone mean?
- hormones that target other endocrine glands
