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58 Cards in this Set

  • Front
  • Back
What do the follicle cells produce?
thyroid hormones
What are the thyroid hormones?
T₃ and T₄ (commonly called thyroxine)
What are the effects of thyroid hormone?
Primary effect — ↑ in metabolic rate
• ↑ O₂ consumption
• produces heat as cell consumes more energy
To meet this increased metabolic demand and ensure blood flow...
• ↑ heart rate and contraction strength (~ ↑ BP)
• ↑ respiratory rate
• ↑ carbohydrates, fat & protein metabolism (need fuel)

Important for nervous system & skeletal development, maturation of reproduction system and growth (works with GH)
Thyroid Hormone Regulation
Negative feedback loop
Parafollicular cells (C cells) produce the hormone _____.
calcitonin
What is the function of calcitonin?
lowers blood Ca²+ levels
• anatagonist to parathyroid hormone (PTH)
Parathyroid Gland
secretes parathyroid hormone (PTH)
Parathyroid hormone
raises Ca²+ levels in blood
• ↓ Ca²+ triggers PTH release
• ↑ Ca²+ inhibits PTH release
Control of Hormone Release
Humoral Stimuli: secretion of hormones in direct response to changing blood levels of ions and nutrients

Example: Ca²+ concentration in blood
• ↓ Ca²+ in blood stimulates parathyroid glands to secrete PTH (parathyroid hormone)
• PTH causes Ca²+ to ↑ ... and stimulus is removed
Adrenal (Suprarenal) Glands
Structurally & functionally they are 2 glands in 1
• adrenal cortex
• adrenal medulla
adrenal cortex
glandular tissue

• synthesizes & release steroid hormones called corticosteroids
1. Mineralcorticoids (aldosterone)
2. Glucocorticoids (cortisol)
3. Androgens (sex steroids)
adrenal medulla
neural tissue that acts as part of SNS

• synthesizes & releases catecholamine hormones
1. Epinephrine
2. Norepinephrine
What are the three layers of the Adrenal cortex?
1. Zona glomerulosa
2. Zona fasiculata
3. Zona reticularis
Zona glomerulosa
mineralocorticoids (cheifly aldosterone)

• promote Na+ retention and K+ excretion by kidneys
∙ removes Na+ from urine forming in kidneys & returns it to the blood
∙ exchanges K+ for Na+ at kidneys; K+ is excreted in urine
Mineralcorticoids
regulate mineral & water balance
Aldosterone
most important mineral corticoid

Aldosterone secretion is stimulated by:
• high blood K+
• low blood Na+
• ↓ blood volume or pressure

Where Na+ goes, water follows: aldosterone also helps regulate blood volume & pressure
Zona fasiculata
glucocorticoids (chiefly cortisol)

Glucocorticoids - help body resist stress or intermittent food uptake by:
• keeping blood glucose levels relatively constant
• regulated by negative feedback

Rising cortisol levels inhibit anterior pituitary (ACTH) & hypothalamus (CRH)
Glucocorticoids
Glucocorticoids - help body resist stress or intermittent food uptake by:
• keeping blood glucose levels relatively constant
• regulated by negative feedback
What is the stimuli and effect of the zone fasiculata
Stimuli: stress or hypoglycemia cause CRH release
Effect: cortisol released to ↑ plasma levels of glucose, fatty acids & amino acids:
1) glucogenesis - glucose synthesis from fats and proteins in liver
• especially between meals
• glucose sparing effect - "save" glucose for brain
2) mobilize fatty acids from adipose tissue (for ATP production)
3) break down stored proteins (provides free aa for repair/enzymes)
gluconegenesis
glucogenesis - glucose synthesis from fats and proteins in liver
• especially between meals
• glucose sparing effect - "save" glucose for brain
Zona reticularis
gonadocorticoids (chiefly androgens)

Gonadocorticoids (principally weak androgens)
Weak androgens are converted into:
• testosterone (males)
• estrogens (females)
∙ Gonadocorticoids produced by adrenal gland = insignificant compared to amount from gonads
What is the effect and regulation of the zone reticularis?
Effect: onset of puberty, appearance of secondary sex characteristics (7-13 years)
Regulation: release seems to be stimulated by ACTH (but gonadocorticoids do not seem to exert feedback inhibition on ACTH)
Adrenal medulla
• secretory activities controlled by sympathetic division of ANS
• Chromaffin cells - produce epinephrine (adrenaline) & noreinephrine

Secretion of these hormones cause:
1) Blood glucose levels to rise
2) Blood vessels constrict
3) Blood diverted to the brain, heart, and skeletal muscle
Secretion of chromaffin cells cause:
1) Blood glucose levels to rise
2) Blood vessels constrict
3) Blood diverted to the brain, heart, and skeletal muscle
Chromaffin cells produce
epinephrine (adrenaline) & norepinephrine
What type of organ in the pancreas? (Endocrine and/or Exocrine)
endocrine and exocrine organ
Exocrine (pancreas)
acinar cells produce enzyme-rich alkaline juice used for digestion
Endocrine (pancreas)
pancreatic islets produce hormones
Pancreatic islets (islets of Langerhans) contain:
Alpha (α) cells and Beta (β) cells
Alpha (α) cells
produce glucagon
Beta (β) cells
produce insulin
What is the target, effect and regulation of glucagon?
Hyperglycemic agent: increases blood glucose
Target: liver
Effect:
•Glycogenolysis
• Gluconeogenesis

Glucose then enters the blood

Regulation: stimulated by falling blood glucose
glycogen
short-term energy storage of glucose
glycogenolysis
breakdown of glycogen to glucose
gluconeogenesis
synthesis of glucose
What is the target, effect and regulation of insulin?
Hypoglycemic agent - lowers blood glucose levels
Target: most cells of the body
Effect:
• Enhances transport of glucose into body cells
• Stimulates glycogen formation at liver

Glucose then leaves the blood

Regulation: stimulated by rising blood glucose
Fill in the numbers
1. insulin
2. insulin
3. glucose
4. glycogen
5. glucagon
6. glucagon
7. glycogen
What is the function and stimulus of glucagon?
Glucagon: α cells
Function: ↑ blood glucose concentration
Stimulus: low blood glucose concentration "When glucose is gone"
What is the function and stimulus of insulin?
Insulin: β cells
Function: ↓ blood glucose concentration
Stimulus: high blood concentration
What is diabetes mellitus?
disorder results from insulin deficiency or resistance → leading to high blood glucose
What is diabetes insipidus?
disorder caused by hypo secretion of ADH (disables water conservation at kidneys)
Explain Diabetes Mellitus Type 1:
What is the Onset, Prevalence, β cells, treatment?
Onset: Juvenile onset
Prevalence: 5-10%
Cause: ~ auto-immune response
β cells: Immune system destroys β cells → failure to produce insulin
Treatment:
Explain Diabetes mellitus Type 2:
What is the Onset, Prevalence, Cause, β cells, Treatment?
Onset: Adult Onset
Prevalence: 90-95%
Cause: Linked to sedentary lifestyle, poor diet, obesity
β cells:
Treatment:
Pineal Gland
• Small gland hanging from roof of 3rd ventricle of brain
• Pinealocytes secrete melantonin
What is melantonin?
• involved in day/night cycles (hight at night; low in day)
• physiological processes that have rhythmic variations (body temperature, sleep, appetite)
What are female gonads?
Paired ovaries in abdominopelvic cavity produce estrogens and progesterone
What is the function of estrogens and progesterone?
• maturation of reproductive organs
• appearance of secondary sexual characteristics
• breast development and cyclic changes in uterine mucosa
What are male gonads?
testes located in an extra-abdominal sac (scrotum) produce testosterone
What is the function of testosterone?
• initiates maturation of male reproductive
• causes appearance of secondary sexual characteristics and sex drive
• necessary for sperm production
• maintains sex organs in their functional state
What are some other hormone producing tissues?
1. adipose tissue
2. thymus
3. heart
4. kidneys
5. digestive system
What two peptide hormones does adipose tissue produce?
Leptin and Resistin
What is leptin?
feedback control for appetite
• when you eat → leptin is released (= feel full)
• some obese individuals appear to have defective leptin receptors
What is resistin?
• decreased insulin sensitivity of body cells (insulin antagonist)
• was thought could be "missing link" between obesity and type II Diabetes
What is the thymus?
produces hormone thymosin
• essential for T lymphocyte development & activity
What hormone(s) is the heart responsible for producing?
produced natriuretic peptides (ANP/atrial NP & BNP/brain NP)
• both reduce blood volume & blood pressure
What hormone is the kidney responsible for producing?
erythopoietin (EPO) - red blood cell production
What hormones is the Digestive System responsible for producing?
gastrin - coordinates digestive activities
secretin - coordinates digestive activity
CCK - coordinates digestive activities