Hormones Flashcards
Steroid vs non- steroid hormones (5- each)
Steroid:
- lipid soluble
- bound to a protein carrier
- receptor on the INSIDE of target cell
- mobil receptor model
- rapid long lasting response
Non-steroid:
- water soluble
- unbound
- receptor in the OUTSIDE of target cell
- 2nd messenger model
- short acting response
what is the Mobile-receptor model
Steroid hormone passes through the cell wall and binds to a receptor; that receptor complex then moves in to the nucleus; induces transcription; leading to translation= new protein made; that protein causes an effect.
what is the second messenger model
non-steroidal hormone CANNOT pass though the cell membrane; it binds to an external receptor; leading to the activation of an internal pathway change; activating second messenger
Which gland does the hypothalamus secret to?
Without the hormones the target glands will…
With excess hormone the glands will… EG…
- anterior pituitary
- not enough= atrophy
- too much= undergo hyperplasia and hypertrophy
Hypertrophy and hyperplasia of the Thyroid gland: Hyperthyroidism
Anterior Pituitary
Posterior Pituitary
Adenohypophysis, “aneno”= gland, “A” think Anterior
Neurohypophysis, “neuro”, posterior
Adenohypophysis
Neurohypophysis
-the gland and the mode of communication
- Hypothalamus communicates with the ANT PIT by secreting regulatory hormones into the BLOOD STREAM (via infundibula)
- Hypothalamus communicates with the POST PIT by direct NEURONAL connections
After simulation they each release their hormones into systemic blood supply
Thyroid Hormone (TH) Function (4)
Affects growth and maturation of tissues, cell metabolism, heat production, and oxygen consumption
Calcitonin
who secretes it
function
Secreted by the thyroid
- Regulation of blood calcium and bone density
- Inhibition of osteoclasts/ stimulation of osteoblasts
- Too much Ca++ in the blood= secrete calcitonin to move Ca++ into bone (increasing its density)
- Calcitonin decreases blood Ca++ and increases bone density!
Parathyroid Hormone function
hypersecretion
hyposecretion
-Antagonist (works opposite) to Calcitonin
-Stimulation of osteoclasts (bone breakdown, increasing Ca++ in blood)
hypersecretion leads to osteoporosis
hyposecretion leads to decreased vit D release from kidney
Pancreatic Islet Cells (2)
function
- Alpha cells – secrete Glucagon
- Beta cells – secrete Insulin
Alpha cells
Beta cells
-secrete Glucagon
“you secrete glucose when your glucagon is gone” (hypoglycemic)
Works in the liver to secrete glucose and raise blood sugar.
-secrete Insulin when hyperglycemic to lower blood sugar.
Works in the liver to take up glucose and store as glycogen.
How do beta cells work to facilitate the rate of glucose uptake by cells?
Glucose requires facilitated diffusion to enter cell. Insulin binds in insulin receptors and stimulates the opening of the glucose channel.
Therefore insulin is the KEY that allows our cells to take up sugar
How do alpha cells work to increase blood glucose?
The liver is stimulated:
- Glycogenolysis- breakdown of glycogen
- Gluconeogenesis- formation of glucose from non-sugar products
- Lipolysis- break down of fat into sugar, keto body
Adrenal cortex (3 hormones) 80% of an adrenal gland’s total weight
Adrenal medulla (1)
- Aldosterone
- Cortisol
- Weak androgens and estrogens
Innervation by SNS
-Catecholamines (Epi/norepi) into blood
Adrenal Cortex
3 layers and what they regulate
1) Glomerulosa (salty)- Mineralcorticoids (aldosterone), regulates Na+
2) Fasciculata (sweet)- Glucocorticoids (cortisol), increase blood glucose
3) Reticularis (sex)- Weak Androgens (DHEA), sex development
(SALTY) Mineralocorticoids- Aldosterone
what it does
what this causes in the DCT
what it is regulated by
Aldosterone turns on Na+/K+ pump in the DCT and collecting duct of cells
↑ Na+ uptake
↑ Na retention with LOSS of K+ and H+
Regulation by the renin-angiotensin system
(SWEET) Glucocorticoids - Cortisol
Released with bodily stress ↑ blood sugar by gluconeogenesis Anti-inflammatory Growth suppression Influences awareness and sleep habits Inhibits bone matrix-protein matrix (decrease bone density)
(SEX) Adrenal estrogens and androgens
estrogen and Androgens
function
Estrogen secretion is minimal (vs. ovary)
Needed in men b/c no ovary
Androgens – weak
DHEA
Converted by peripheral tissues to stronger androgens such as testosterone
Needed in women b/c no testes
Panhypopituitarism
what it is
cause
“pan”=all, “hypo”; ant pit hormones are low
Due to infundibulum damage