Chapter 12: Hormones, Physical Activity, and Exercise Training

Question 1

Three components of endocrine system

Answer 1

1. Host gland
2. Hormones
3. Target (receptor) cells or organs

Question 2

Hormones influence cellular function by initiating a predictable series of actions within target cell by one of four mechanisms

Answer 2

1. Change intracellular proteins synthesis rate
2. alter enzyme activity rate
3. Modify cell membrane transport
4. influence secretory activity

Question 3

Three mechanisms stimulate endocrine gland function:

Answer 3

Hormonal, Humoral, neural

Question 4

Growth hormone

Answer 4

facilitates protein synthesis by:

1. increasing amino acid transport through plasma membranes
2. stimulating RNA formation
3. Activating cellular ribosomes that increase protein synthesis

Question 5

Thyrotropin (TSH)

Answer 5

also known as thyroid-stimulating hormone, maintains growth and thyroid gland development and regulation of hormone output from thyroid cells. PA usually increases anterior pituitary TSH output

Question 6

Posterior pituitary hormones

Answer 6

Stores antidiuretic hormone (ADH or vasopressin) and oxytocin

Question 7

Thyroid hormones: Calcitonin and Thyroxine

Answer 7

Hyper secretion
1. Increases VO2 and metabolic heat production during rest
2. increases protein catabolism causing muscle weakness, weight loss
3. Heightens reflex activity and psychological disturbances
4. causes tachycardia

Hyposecretion

5. Reduces metabolic rate leading to infection
6. decreases protein synthesis, brittle nails, thinning hair, dry and thinning skin

Question 8

parathyroid hormone raises plasma Ca2+ concentrations in three ways

Answer 8

1. mobilizes Ca2+ from bone
2. Enhances renal Ca2+ reabsorption
3. indirectly increases intestinal Ca2+ absorption by its influence on vitamin D3

Question 9

Adrenal medulla forms part of the SNS:

Answer 9

prolongs and augments sympathetic neural effects by secreting epinephrine and noepinephrine

Question 10

Four factors determine catecholamine response to PA:

Answer 10

intensity, duration, age, gender

Question 11

Adrenal cortex hormones

Answer 11

1. Mineralcorticoids; aldosterone (regulates mineral salts Na and K in ECF)
2. Glucocorticoids; cortisol (stress hormone)
3. Androgens (promote sex-specific characteristics)

Question 12

Islets of Langerhans contain four distinct cell types, each producing a different peptide hormone:

Answer 12

1. beta cells (produce insulin and amylin)
2. Alpha cells (secrete glucagon)
3. D cells (secrete somatostatin)
4. PP cells (produce pancreatic polypeptide)

Question 13

Five factors influence insulin release after meal

Answer 13

increased blood glucose concentration, increased blood amino acid concentration, gastrointestinal tract hormones, parasympathetic nervous system stimulation, sympathetic nervous system stimulation

Question 14

Insulin exerts action on glucose in four ways:

Answer 14

1. increases glucose transport into most, but not all insulin-sensitive cells (most important)
2. Enhances cellular utilization and glucose storage
3. enhances utilization of amino acids
4. promote fat synthesis

Question 15

Glucagon secretion

Answer 15

increases blood glucose levels and stimulates liver glycogenolysis, gluconeogenesis, lipid catabolism

Question 16

Type 1 diabetes

Answer 16

body’s failure to produce insulin

Question 17

Type 2 diabetes

Answer 17

relative insulin deficiency that results in hyperglycemia

Question 18

Gestational diabetes

Answer 18

afflicts about 4% of all pregnant women

Question 19

Prediabetes

Answer 19

blood glucose reaches higher-than-normal levels but not high enough for a diagnosis of type 2 diabetes

Question 20

two factors predispose to diabetes

Answer 20

1. genetic predisposition
2. environmental triggers

Question 21

Physical activity benefits for T2DM

Answer 21

improves glycemic control, cardiovascular function, body composition, psychological profile, reduces broad array of risks for heart disease

Question 22

two mechanisms explain reduced training response for insulin and glucagon

Answer 22

1. increased muscle and fat tissue sensitivity insulin
2. increased percentage contribution of fat catabolism for fuel during submax P (decreased carbohydrate metabolism lowers insulin requirement)