Physiology Exam #4 Part 1: Endocrinology

Front 1

True or False: All tissues are bathed by blood which contains hormone.

Back 1

False - not the brain or placenta

Front 2

What is the advantage of most tissues being bathed by blood which contains hormone?

Back 2

allows body to adjust to changing conditions and function synchronously

Front 3

True or False: Hormones can be released in response to nerve stimulation.

Back 3

True

Front 4

What is the purpose of an immunoassay?

Back 4

recognizes a single hormone

Front 5

What enzymes are activated by cAMP?

Back 5

adenylyl cyclase
protein kinase A

Front 6

What is cAMP made from?

Back 6

ATP

Front 7

What does diacylglycerol activate?

Back 7

protein kinase C

Front 8

What is the effect of inositol triphosphate?

Back 8

triggers release of Ca2+ from endoplasmic reticulum

Front 9

What triggers release of Ca2+ from the endoplasmic reticulum?

Back 9

inositol triphosphate

Front 10

What activates protein kinase C?

Back 10

diacylglycerol

Front 11

What enzyme catalyzes the conversion of phosphatidylinositol 4,5-diphosphate to inositol 1,4,5-triphosphate and diacylglycerol?

Back 11

phospholipase C

Front 12

What reaction is catalyzed by phospholipase C?

Back 12

conversion of phosphatidylinositol 4,5-diphosphate to inositol 1,4,5-triphosphate and diacylglycerol

Front 13

What activates adenylyl cyclase and protein kinase A?

Back 13

cAMP

Front 14

What are the three regions of the pituitary gland?

Back 14

anterior lobe - adenohypophysis
posterior lobe - neurohypophysis
intermediate lobe - pars intermedia

Front 15

Which hormones are produced by the anterior lobe of the pituitary gland?

Back 15

FSH - follicle stimulating hormone
LH - luteinizing hormone
ACTH - adrenocorticotropic hormone
GH - growth hormone
TSH - thyroid stimulating hormone
PRL - prolactin

Front 16

Which gland produces the following hormones: FSH, LH, ACTH, GH, TSH, PRL?

Back 16

pituitary gland (anterior lobe)

Front 17

True or False: Growth hormone directly stimulates growth.

Back 17

False - IGF-I stimulates growth

Front 18

Where are GHRH and somatostatin produced?

Back 18

hypothalamus

Front 19

What is the function of somatostatin?

Back 19

inhibits release of growth hormone, insulin, and glucagon

Front 20

What inhibits release of growth hormone from the pituitary gland?

Back 20

somatostatin

Front 21

What promotes release of growth hormone from the pituitary gland?

Back 21

growth hormone releasing hormone (GHRH)

Front 22

Growth hormone increases the activity of what kind of cells?

Back 22

chondrocytes

Front 23

What kinds of extrinsic factors affect growth?

Back 23

protein
vitamins
minerals
calories

Front 24

True or False: GH fails to promote growth in absence of insulin or thyroid hormones.

Back 24

True

Front 25

What are the three phases of growth?

Back 25

in utero
prepubertal
puberty

Front 26

Which phase of growth is primarily due to GH?

Back 26

prepubertal

Front 27

What is involved in growth during the in utero phase?

Back 27

IGF-I and IGF-II

Front 28

What is involved in growth during the prepubertal phase?

Back 28

GH and thyroid hormones

Front 29

What hormone is involved in growth during puberty?

Back 29

testosterone or estrogen

Front 30

What causes growth to cease during puberty?

Back 30

estrogen

Front 31

In what age range does IGF-I peak?

Back 31

13-17

Front 32

What causes linear growth to stop?

Back 32

closure of the epiphyses of long bones

Front 33

True or False: Growth hormone is important in adults.

Back 33

True

Front 34

True or False: GH plasma levels are low during the first days of life and increase by about 2 weeks of age.

Back 34

False

Front 35

When in the day do growth hormone levels peak?

Back 35

shortly after the onset of sleep

Front 36

What activites cause an increase in the level of growth hormone?

Back 36

exercise
eating
fasting

Front 37

What are the physiological effects of GH on proteins?

Back 37

increases amino acid transport into cells (positive nitrogen balance)
increases mRNA (and protein) synthesis

Front 38

What are the physiological effects of GH on fatty acids?

Back 38

increases release from adipose tissues (and blood lipid levels)
increases usage of fatty acids as energy source
ketosis from prolonged GH excess

Front 39

What are the physiological effects of GH on carbohydrates?

Back 39

decreases utilization by inhibiting glucose uptake into muscle
increases tissue glycogen stores
increases blood carbohydrate levels

Front 40

True or False: Pituitary diabetes severely affects glucose utilization.

Back 40

False - only moderate effect

Front 41

True or False: Prolonged elevation of blood glucose can lead to true diabetes.

Back 41

True - due to burn out of insulin producing cells of the pancreas

Front 42

True or False: IGF-I has direct effect on linear growth.

Back 42

True

Front 43

What disease states are caused by excess growth hormone?

Back 43

gigantism in growing person
acromegaly if linear growth has stopped

Front 44

What is acromegaly?

Back 44

excess growth of soft tissues due to excess growth hormone

Front 45

What disease state is caused by growth hormone deficiency?

Back 45

dwarfism

Front 46

What disease state is caused by IGF-I deficiency?

Back 46

Laron dwarfism

Front 47

True or False: Laron dwarfism cannot be treated with growth hormone.

Back 47

True

Front 48

Laron dwarfism is caused by deficiency of which hormone?

Back 48

IGF-I

Front 49

Is growth hormone deficiency a primary or secondary growth abnormality?

Back 49

secondary

Front 50

Is osterochondrodysplasia a primary or secondary growth abnormality?

Back 50

primary

Front 51

What is caused by excess ACTH?

Back 51

Addisons and Cushing syndromes and skin darkening

Front 52

Which hormones are released from the intermediate lobe of the pituitary gland?

Back 52

MSH - melanocyte stimulating hormone

Front 53

αMSH has the same first thirteen amino acids as which other hormone?

Back 53

ACTH

Front 54

Which hormones are released from the posterior lobe of the pituitary gland?

Back 54

ADH - antidiuretic hormone
oxytocin

Front 55

Where are ADH and oxytocin produced?

Back 55

hypothalamus
(ADH in supraoptic nuclei)
(oxytocin in paraventicular nuclei)

Front 56

Which gland releases melanocyte stimulating hormone?

Back 56

pituitary gland (intermediate lobe)

Front 57

How are ADH and oxytocin transported from the hypothalamus to the posterior lobe of the pituitary gland?

Back 57

along axons of the neurohypophyseal tract

Front 58

What is the effect of ADH on the kindeys?

Back 58

increased water reabsorption due to increased permeability of collecting ducts

Front 59

What is caused by a lack of ADH?

Back 59

diabetes insipidus - excretion of large volumes of urine

Front 60

What is caused by a lack of insulin?

Back 60

diabetes mellitus

Front 61

Dilute urine is associated with which type of diabetes?

Back 61

diabetes insipidus

Front 62

Sweet urine is associated with which type of diabetes?

Back 62

diabetes mellitus

Front 63

What are some factors that can increase release of ADH from the posterior lobe of the pituitary gland?

Back 63

surgical stress
morphine
nicotine
barbiturates

Front 64

What is the threshold of plasma osmolarity for the release of ADH from the posterior lobe of the pituitary gland?

Back 64

280 mOsm

Front 65

What is the normal plasma osmolarity?

Back 65

290 mOsm

Front 66

What are some factors that can decrease release of ADH from the posterior lobe of the pituitary gland?

Back 66

alcohol
opiate antagonists

Front 67

What is caused by massive amounts of ADH?

Back 67

hemmorhage or circulatory shock due to contraction of smooth muscles of blood vessels (increases blood pressure)

Front 68

What are the effects of oxytocin?

Back 68

contraction of smooth muscle of the uterus (parturition) and myoepithelial cells of the breasts (milk letdown effect)

Front 69

True or False: Oxytocin causes milk to be ejected into the ducts of the breasts.

Back 69

True

Front 70

Which gland produces calcitonin?

Back 70

thyroid gland (C-cells)

Front 71

Which hormone is produced by the C-cells (parafollicular cells) of the thyroid gland?

Back 71

calcitonin

Front 72

True or False: Calcitonin is a thyroid hormone.

Back 72

False - peptide hormone

Front 73

Where in the thyroid gland is thyroglobulin located?

Back 73

colloid (middle of all of the follicles)

Front 74

Where is iodide absorbed?

Back 74

intestine

Front 75

What is the minimum daily requirement of iodide?

Back 75

75 µg

Front 76

How much iodide is in a typical daily diet in the U.S.?

Back 76

300-400 µg

Front 77

What are the four classes of cell membrane hormone receptors?

Back 77

G protein coupled
tyrosine kinase
cytokine
TGF-β

Front 78

Is iodide taken up by the cells of the thyroid gland by active transport or passive diffusion?

Back 78

active transport

Front 79

How many times greater can iodide concentration be in the cells of the thyroid gland compared to the blood?

Back 79

25-50

Front 80

What do G protein coupled receptors activate?

Back 80

adenylyl cyclase (ATP --> cAMP)

Front 81

True or False: Thyroglobulin is a glycoprotein.

Back 81

True

Front 82

True or False: Under normal circumstances, there is a limited store of colloid in the thyroid gland.

Back 82

False - normally a vast store

Front 83

What is a goiter?

Back 83

enlarged thyroid gland

Front 84

What is the function of thiocyanates and perchlorate?

Back 84

block uptake of iodide

Front 85

What is the function of propylthiouracil and methimazole?

Back 85

block organification and coupling of iodide

Front 86

What are thiocyanates, perchlorate, propylthiouracil, and methimazole known as?

Back 86

goitrogens

Front 87

What is the name of the enzyme that deiodinates monoiodotyrosine and diiodityrosine?

Back 87

iodotyrosine dehalogenase

Front 88

Which is secreted from the thyroid gland in higher amounts: T3 or T4?

Back 88

T4

Front 89

True or False: The vast majority of T3 and T4 are covalently bound to specific circulating proteins.

Back 89

False - noncovalently bound

Front 90

What proteins do T3 and T4 bind to?

Back 90

thyroxine binding globulin (TBG)
thyroxine binding prealbumin (TBPA)
albumin

Front 91

True or False: T4 is converted to T3 in peripheral tissues.

Back 91

True

Front 92

True or False: If synthesis of thyroid hormone were to suddenly stop, there would be rapid changes in thyroid hormone levels.

Back 92

False

Front 93

Which hormones control thyroid hormone secretion?

Back 93

thyrotropin-releasing hormone (TRH)
thyroid stimulating hormone (TSH)
T3 & T4

Front 94

What is thyrotropin-releasing hormone (TRH) released from?

Back 94

hypothalamus

Front 95

What is the effect of thyrotropin-releasing hormone (TRH)?

Back 95

stimulates release of thyroid stimulating hormone (TSH) from the anterior lobe of the pituitary glamd

Front 96

What processes does thyroid stimulating hormone (TSH) stimulate?

Back 96

iodide uptake
organification of iodide
coupling of iodide
thyroglobulin breakdown

Front 97

Which subunit is the same for TSH, FSH, LH, and LCG?

Back 97

α-subunit

Front 98

Do T3 & T4 inhibit or stimulate release of TSH from the anterior lobe of the pituitary gland?

Back 98

inhibit

Front 99

What can result from an absence of T3 & T4?

Back 99

goiter

Front 100

Does increased iodide cause a decrease or increase in responsiveness to TSH?

Back 100

decrease

Front 101

Does decreased iodide cause a decrease or increase in responsiveness to TSH?

Back 101

increase

Front 102

What is the most common form of hyperthyroidism?

Back 102

Graves disease

Front 103

Which hormone is found in most cases of Graves disease?

Back 103

long acting thyroid stimulator (LATS)

Front 104

What disease is caused by absence of thyroid hormones?

Back 104

cretinism

Front 105

Do thyroid hormones lead to decreased or increased O2 consumption by almost all body tissues?

Back 105

increased

Front 106

Do low amounts of thyroid hormones cause an increase in protein breakdown or synthesis?

Back 106

increase in protein synthesis

Front 107

Do excessive amounts of thyroid hormone cause an increase in protein breakdown or synthesis?

Back 107

increase in protein breakdown

Front 108

Does hyperthyroidism cause a decrease or increase in heart rate?

Back 108

increase

Front 109

Does hypothyroidism cause a decrease or increase in heart rate?

Back 109

decrease

Front 110

What is myxedema and what is it caused by?

Back 110

puffiness of skin due to increased water retention caused by low levels of thyroid hormones

Front 111

True or False: Thyroid hormones decrease sensitivity of heart to catecholamines.

Back 111

False - increase sensitivity

Front 112

What are poor toleration of cold, coarse fair, husky & low voice, and slow mental processes characteristic of?

Back 112

severe myxedema from hypothyroidism

Front 113

True or False: TSH levels are elevated in hypothyroidism.

Back 113

True - due to loss of feedback inhibition

Front 114

How can cretinism be treated?

Back 114

thyroid hormone replacement

Front 115

What are the characteristics of cretinism?

Back 115

dwarfed, mentally retarded children

Front 116

What are hear intolerance, nervousness, and exophtalamus characteristic of?

Back 116

hyperthyroidism

Front 117

True or False: Thyroid gland tumors are associated with goiters.

Back 117

False

Front 118

True or False: Graves disease is associated with goiter.

Back 118

True

Front 119

What percentage of the pancreas is made up of Islets of Langerhans?

Back 119

1-2%

Front 120

What do the α cells of the pancreas secrete?

Back 120

glucagon

Front 121

Are the α cells of the pancreas responsible for an anabolic or catabolic effect?

Back 121

catabolic

Front 122

Which pancreatic cells secrete glucagon?

Back 122

α cells

Front 123

What percentage of pancreatic cells are α cells?

Back 123

25%

Front 124

What is secreted by the β cells of the pancreas?

Back 124

insulin

Front 125

Are the β cells of the pancreas responsible for an anabolic or catabolic effect?

Back 125

anabolic

Front 126

What percentage of pacreatic cells are β cells?

Back 126

60%

Front 127

What is secreted by the δ cells of the pancreas?

Back 127

somatostatin

Front 128

What is secreted by the F cells of the pancreas?

Back 128

pancreatic polypeptide

Front 129

True or False: Glucagon, somatostatin, and pancreatic polypeptide are only secreted by cells of the pancreas?

Back 129

False - also by cells in mucosa of GI tract

Front 130

What type of hormone is insulin?

Back 130

polypeptide hormone

Front 131

What is the structure of insulin?

Back 131

A and B chains connected by disulfide bonds

Front 132

What percentage of the population has diabetes mellitus?

Back 132

5%

Front 133

Which chain in insulin is longer: A chain or B chain?

Back 133

B chain

Front 134

Is juvenile onset diabetes a type 1 or type 2 diabetes?

Back 134

type 1

Front 135

True or False: There is a strong genetic link for type 2 diabetes?

Back 135

True

Front 136

At what age does type 2 diabetes generally occur?

Back 136

after 40

Front 137

True or False: Type 2 diabetes can often be controlled with diet.

Back 137

True

Front 138

What does hyperglycemia refer to?

Back 138

elevated plasma glucose levels because glucose uptake by many tissues is decreased

Front 139

What is the normal plasma glucose level?

Back 139

90 mg%

Front 140

What is the normal blood glucose level in urine?

Back 140

0

Front 141

What does glycosurea refer to?

Back 141

capacity of kidneys to reabsorb glucose is exceeded

Front 142

What does polyurea refer to?

Back 142

high osmolarity due to glucose draws in water causing increased urine flow

Front 143

What does ketosis refer to?

Back 143

increased protein and fat catabolism due to low intracellular glucose levels

Front 144

What can ketosis lead to if left untreated?

Back 144

acidosis and coma

Front 145

What does polydipsia refer to?

Back 145

excessive thirst

Front 146

What does polyphagia refer to?

Back 146

increased appetite with weight loss

Front 147

What are 7 characteristics of diabetes mellitus?

Back 147

hyperglycemia
glycosurea
polyurea
ketosis
polydipsia
polyphagia
reduced growth

Front 148

Which enzyme in the liver is induced by insulin?

Back 148

glucokinase (catalyzes glucose --> glucose-6-P)

Front 149

True or False: Insulin increases the number of glucose transporters in the cell membrane of liver cells.

Back 149

False

Front 150

What are some tissues that are not affected by insulin?

Back 150

intestine
kidneys
brain
red blood cells

Front 151

True or False: Oral glucose and intravenous glucose promote insulin release with the same effectiveness.

Back 151

False - oral glucose is more effective

Front 152

What happens in the two phases of the effect of glucose?

Back 152

First Phase: insulin peaks within 5 minutes due to release of existing stores
Second Phase: due to synthesis of insulin

Front 153

What is the effect of the drug metformin?

Back 153

stimulates sensitivity to insulin

Front 154

Prolonged stimulation by glucose can lead to hypertrophy and exhaustion of which cells of the pancreas?

Back 154

β cells

Front 155

Which cells in the gut secrete glucose-dependent insulinotropic peptide (GIP)?

Back 155

K cells

Front 156

Which cells in the gut secrete glucagon-like peptide-1 (GLP-1)?

Back 156

L cells

Front 157

What are the two incretins from the gut that are responsible for oral glucose being more effective than intravenous glucose in promoting insulin release?

Back 157

glucose-dependent insulinotropic peptide (GIP)
glucagon-like peptide-1 (GLP-1)

Front 158

True or False: Amino acids and β-keto acids cause insulin release.

Back 158

True

Front 159

Does glucagon lower or raise blood glucose levels?

Back 159

raise

Front 160

What kind of hormone is glucagon?

Back 160

polypeptide hormone

Front 161

True or False: Elevated blood glucose levels alone can cause a decrease in glucagon secretion.

Back 161

False - some insulin must be present

Front 162

Which gene in the Y chromosome is the sex-determining region?

Back 162

SRY gene

Front 163

True or False: Genetic sex is determined at the time the egg is fertilized by the sperm.

Back 163

True

Front 164

What are the accessory sex tissues in males?

Back 164

epididymus
vas deferens
seminal vesicles
ejaculatory duct

Front 165

What are the accessory sex tissues in females?

Back 165

uterus
fallopian tubes

Front 166

What is a Barr body?

Back 166

the inactive X chromosome in somatic cells of a female

Front 167

True or False: An embryo at the seventh week of intrauterine life is equppied with the primordia of both the male and female genital ducts.

Back 167

True

Front 168

Which ducts develop into the accessory sex tissues in females?

Back 168

mullerian ducts

Front 169

Which ducts develop into the accessory sex tissues in males?

Back 169

Wolffian ducts

Front 170

Do the mullerian ducts develop into the accessory sex tissues in females or males?

Back 170

females

Front 171

Do the Wolffian ducts develop into the accessory sex tissues in females or males?

Back 171

males

Front 172

What factors lead to development of the male accessory sex tissues?

Back 172

androgens and mullerian inhibiting factor from the fetal testis

Front 173

What makes up 80% of the testes?

Back 173

seminiferous tubules

Front 174

What do the seminiferous tubules of the testes drain into?

Back 174

epididymis

Front 175

How much is the difference in temperature in the scrotum compared to the body core?

Back 175

1-2ºC lower

Front 176

What percentage of the testes are made up of seminiferous tubules?

Back 176

80%

Front 177

What are the two types of cells in the testis?

Back 177

Sertoli cells
Leydig (interstitial) cells

Front 178

Which cells of the testis act as a source of nourishment for spermatids?

Back 178

Sertoli cells

Front 179

Which cells of the testis extend from the basement membrane to the lumen of the seminiferous tubule?

Back 179

Sertoli cells

Front 180

What is the function of the Sertoli cells of the testis?

Back 180

act as a source of nourishment for spermatids

Front 181

Where in the testis are the Sertoli cells located?

Back 181

extending from the basement membrane to the lumen of the seminiferous tubule

Front 182

Where in the testis are the Leydig cells located?

Back 182

between the seminiferous tubules

Front 183

Which cells of the testis are the major source of androgens?

Back 183

Leydig cells

Front 184

What is the major androgen produced by the Leydig cells of the testis?

Back 184

testosterone

Front 185

Which cells of the testis are located between the seminiferous tubules?

Back 185

Leydig cells

Front 186

What is the function of the Leydig cells of the testis?

Back 186

major source of androgens

Front 187

True or False: The prepubertal testis produces extremely low levels of testosterone.

Back 187

True

Front 188

What is the testosterone level in adult males?

Back 188

600 ng/dL

Front 189

What are three forms of testosterone in the body?

Back 189

1-2% free form
65% noncovalently bound to sex steroid-binding globulin
33% bound to albumin & other proteins

Front 190

At approximately what age does the lumen of the seminiferous tubules develop and spermatogenesis begin in males?

Back 190

12

Front 191

True or False: In a prepubertal male, the seminiferous tubules contain spermatogonia and Sertoli cells.

Back 191

True (but they are solid - no lumen)

Front 192

Approximately how many sperm are produced by a male each day?

Back 192

100-200 million

Front 193

Describe spermatogenesis up to the development of spermatozoa.

Back 193

- spermatogonia undergo mitosis to produce primary spermatocytes
- primary spermatocytes undergo meiosis to produce secondary spermatocytes
- secondary spermatocytes undergo meiosis to produce spermatids
- spermatids lose cytoplasm, form a tail, and develop into spermatozoa

Front 194

True or False: As spermatozoa develop, they are displaced away from the lumen of the testes.

Back 194

False

Front 195

Describe the flow of sperm from the testes out the urethra.

Back 195

- sperm drain from the seminiferous tubules into the epididymis
- sperm move to the vas deferens
- sperm move through the ejaculatory ducts
- sperm move into the urethra in the body of the prostate

Front 196

How long after ejaculation do sperm remain active?

Back 196

about 2 days

Front 197

How long after ejaculation do sperm become capacitated?

Back 197

4-6 hours

Front 198

How many sperm are there in the typical 2-4 mL ejaculate?

Back 198

200-400 million

Front 199

How long does it take for spermatids to develop from spermatocytes?

Back 199

60-70 days

Front 200

True or False: Certain hormones affect the rate of the development of spermatocytes.

Back 200

False

Front 201

How long does it take for sperm to move through the epididymis?

Back 201

2-4 weeks

Front 202

What is the function of the epididymis?

Back 202

allows for the maturation of sperm

Front 203

What is the function of the vas deferens?

Back 203

storage site for sperm

Front 204

True or False: Sperm may remain viable in the vas deferens for several months.

Back 204

True

Front 205

Which structure is the storage site for sperm?

Back 205

vas deferens

Front 206

Which structure allows for the maturation of sperm?

Back 206

epididymis

Front 207

True or False: Testosterone is an anabolic steroid.

Back 207

True

Front 208

What is caused by premature secretion of testosterone?

Back 208

shortened stature due to premature uniting of the epiphysis of long bones

Front 209

True or False: Testosterone causes a decrease in the bone matrix, leading to bone thinning.

Back 209

False

Front 210

Testosterone increases retention of which elements?

Back 210

nitrogen
potassium
phosphorus
calcium

Front 211

What is the effect of leutenizing hormone (LH) on the testes?

Back 211

acts on Leydig cells to promote testosterone synthesis

Front 212

Where is gonadotropin releasing hormone (GnRH) released from?

Back 212

hypothalamus

Front 213

What is the effect of gonadotropin releasing hormone (GnRH) on the testes?

Back 213

stimulates fetal secretion of testosterone

Front 214

Which hormone promotes the synthesis of testosterone by the Leydig cells of the testes?

Back 214

leutenizing hormone (LH)

Front 215

Which hormone stimulates fetal secretion of testosterone?

Back 215

gonadotropin releasing hormone (GnRH)

Front 216

What is the effect of follicle stimulating hormone (FSH) on the testes?

Back 216

acts on Sertoli cells and is required for proper spermatogenesis

Front 217

Which hormone acts on the Sertoli cells of the seminiferous tubules and is required for proper spermatogenesis?

Back 217

follicle stimulating hormone (FSH)

Front 218

True or False: Testosterone depresses hypothalamic release of gonadotropin releasing hormone (GnRH).

Back 218

True

Front 219

What are some causes of hypogonadism?

Back 219

lack of functional testis
lack of LH or FSH secretion
cryptorchidism (undescended testes)
castration

Front 220

What is the effect of hypogonadism on growth and muscle?

Back 220

increase in height and weaker muscles

Front 221

True or False: Hypogonadism developing after puberty will cause the accessory sex glands to decrease in size.

Back 221

True

Front 222

What is secreted by the outer cortex of the adrenal gland?

Back 222

cortisol
aldosterone
weak androgens

Front 223

What is secreted by the inner medulla of the adrenal gland?

Back 223

epinephrine
norepinephrine
dopamine

Front 224

What part of the adrenal gland produces steroids?

Back 224

outer cortex

Front 225

Which part of the adrenal gland produces catecholamines?

Back 225

inner medulla

Front 226

What are the three zones of the adrenal cortex (from outer to inner) and what is secreted from each zone?

Back 226

zona glomerulosa - aldosterone
zona fasciculata - cortisol
zona reticularis - cortisol

Front 227

What is the most important mineralocorticoid?

Back 227

aldosterone

Front 228

Where do mineralocorticoids promote sodium reabsorption?

Back 228

kidney (distal & collecting tubules, part of loop of Henle)
sweat glands
salivary glands
intestinal glands

Front 229

Do mineralocorticoids decrease or increase Cl reabsorption?

Back 229

increase

Front 230

Do mineralocorticoids decrease or increase H excretion?

Back 230

increase

Front 231

Do mineralocorticoids decrease or increase K excretion?

Back 231

increase

Front 232

True or False: Hypoaldosteronism can result in death if untreated.

Back 232

True

Front 233

What is the effect of hypoaldosteronism?

Back 233

decreased cardiac output and shock-like state

Front 234

True or False: In hypoaldosteronism, Na reabsorption decreases in the kidney and there is a decrease in extracellular fluid volume.

Back 234

True

Front 235

What is the effect of hyperaldosteronism?

Back 235

increased cardiac output and hypertension

Front 236

What system controls aldosterone secretion?

Back 236

renin-angiotensin system

Front 237

True or False: A decrease in K concentration leads to an increase in aldosterone secretion.

Back 237

False

Front 238

True or False: An increase in K concentration leads to an increase in aldosterone secretion.

Back 238

True

Front 239

True or False: A decrease in Na concentration leads to an increase in aldosterone secretion.

Back 239

True

Front 240

True or False: An increase in Na concentration leads to an increase in aldosterone secretion.

Back 240

False

Front 241

What is the function of renin?

Back 241

cleaves angiotensinpgen to produce angiotensin I

Front 242

Where in the body does angiotensin-converting enzyme act to convert angiotensin I to angiotensin II?

Back 242

lungs

Front 243

What does angiotensin II cause?

Back 243

release of aldosterone

Front 244

What are ACE inhibitors used as a treatment for?

Back 244

heart failure

Front 245

What results from an absence of cortisol?

Back 245

impaired metabolic function
impaired ability to withstand physical stress

Front 246

True or False: Glucocorticoids cause an increase in the rate of gluconeogenesis in the liver.

Back 246

True

Front 247

Do glucocorticoids cause a decrease or increase in blood glucose levels?

Back 247

increase

Front 248

Do glucocorticoids cause a decrease or increase in protein catabolism in most tissues?

Back 248

increase

Front 249

True or False: Glucocorticoids cause an increase in protein catabolism in the liver.

Back 249

False

Front 250

Do glucocorticoids cause a decrease or increase in fatty acid mobilization?

Back 250

increase

Front 251

True or False: Glucocorticoids have a stimulatory effect on inflammatory and allergic reactions.

Back 251

False

Front 252

Do glucocorticoids inhibit or stimulate secretion of corticotopin releasing hormone (CRH) and adenocorticotopin (ACTH)?

Back 252

inhibit

Front 253

What is the main form of glucocorticoids in the blood?

Back 253

noncovalently bound to corticoid binding globulin (CBG)

Front 254

Does stress inhibit or stimulate the release of glucocorticoids?

Back 254

stimulate

Front 255

When in the day are glucocorticoid plasma levels the highest?

Back 255

shortly before waking up

Front 256

When in the day are glucocorticoid plasma levels the lowest?

Back 256

start of the sleep cycle

Front 257

Is Addisons Disease a condition of hyperadrenalism or hypoadrenalism?

Back 257

hypoadrenalism

Front 258

Is Cushings Disease a condition of hyperadrenalism or hypoadrenalism?

Back 258

hyperadrenalism

Front 259

What are the effects of the loss of glucocorticoids?

Back 259

loss of ability to regulate blood glucose levels
ACTH levels rise due to loss of feedback control
skin darkening

Front 260

What are the effects of having excess glucocorticoids?

Back 260

elevated blood glucose (can lead to diabetes mellitus)
bone & muscle weakness due to extrahapatic breakdown of protein

Front 261

True or False: Cushings Disease can cause masculinization in females.

Back 261

True

Front 262

What kind of cells make up the adrenal medulla?

Back 262

modified ganglion cells

Front 263

Which hormones are catecholamines?

Back 263

epinephrine
norepinephrine

Front 264

Is the secretion of catecholamines from the adrenal medulla controlled by the parasympathetic or sympathetic nervous system?

Back 264

sympathetic

Front 265

Describe the flow of catecholamine formation.

Back 265

tyrosine --> 3,4-dihydroxyphenylalanine --> dopamine -->
norepinephrine --> epinephrine

Front 266

Does norepinephrine act preferentially through α receptors or β receptors?

Back 266

α receptors

Front 267

Does epinephrine act preferentially through α receptors or β receptors?

Back 267

β receptors

Front 268

What are some things increased by cathecholamines?

Back 268

liver glycogenolysis
blood glucose
blood lactate
plasma potassium
plasma free fatty acids
ability to handle emergency situations

Front 269

Which hormone is formed by hydroxylation of vitamin D3?

Back 269

1,25-dihydrocholecalciferol

Front 270

What is the normal plasma calcium level?

Back 270

9-11 mg%

Front 271

What are the three forms of plasma calcium?

Back 271

ionized (50%)
bound to serum proteins (40%)
unionized (10%)

Front 272

What is the effect of low plasma calcium?

Back 272

increased permeability of neuronal membrane causing tetany

Front 273

What is the effect of high plasma calcium?

Back 273

sluggish reflex activity of central nervous system

Front 274

What is the annual turnover of bone calcium in adults?

Back 274

18%

Front 275

What is the annual turnover of bone calcium in infants?

Back 275

100%

Front 276

What is the function of calcium salts in bone?

Back 276

compressional strength

Front 277

What is the function of the organic matrix in bone?

Back 277

tensile strength

Front 278

Is there more organic matrix or salts in bone?

Back 278

salts (75%)

Front 279

What is the primary component of the organic matrix in bone?

Back 279

collagen (97%)

Front 280

What is the function of calcium salts in bone?

Back 280

compressional strength

Front 281

What is the function of the organic matrix in bone?

Back 281

tensile strength

Front 282

Is there more organic matrix or salts in bone?

Back 282

salts (75%)

Front 283

What is the primary component of the organic matrix in bone?

Back 283

collagen (97%)