45 Questions
What is the primary function of endocrine glands?
To secrete hormones directly into the surrounding fluid
Which of the following organs has both endocrine and non-endocrine functions?
Pancreas
What is the role of the hypothalamus in the endocrine system?
To contain cells with endocrine function
What is the mechanism by which hormones affect their target cells?
Through the binding of hormones to receptors on target cells
What is the essential component of thyroid hormones produced in the colloid?
Iodine
What is the classification of hormones derived from amino acids?
Amines, peptides, and proteins
What is the function of the pituitary gland in the endocrine system?
To produce hormones that stimulate other endocrine glands
What is the primary function of the parathyroid hormone (PTH)?
Regulation of blood calcium levels
What is the role of the bloodstream in the endocrine system?
To transport hormones throughout the body
What is the result of abnormally high activity of the parathyroid gland?
Hyperparathyroidism
What is the function of hormones in the regulation of physiological processes?
To regulate various physiological processes
What is the effect of parathyroid hormone deficiency?
Increased muscle twitching
What is the function of the adrenal cortex?
Regulation of long-term stress response
What is the characteristic of amine hormones?
They are synthesized from the amino acids tryptophan or tyrosine
What stimulates the adrenal cortex to produce cortisol?
Adrenocorticotropic hormone (ACTH) from the pituitary
What is the function of the adrenal medulla?
Response to short-term stress
What is the result of stimulation of the adrenal medulla?
Release of epinephrine and norepinephrine
What is the response of the adrenal gland to stress?
Production of epinephrine and norepinephrine
Which hormone is derived from the amino acid tryptophan and helps regulate circadian rhythm?
Melatonin
What type of hormones are derived from lipid cholesterol?
Steroid hormones
How do lipid-derived hormones travel to their target cells?
They are bound to a transport protein
What is the function of a hormone receptor?
To recognize and respond to specific hormones
What is the result of a hormone binding to its receptor?
The target cell responds in a specific way
What is the purpose of negative feedback loops in hormone regulation?
To regulate hormone levels within a narrow range
Which gland is located anterior to the trachea, just inferior to the larynx?
Thyroid gland
What is the composition of the thyroid gland?
Mostly of thyroid follicles
What is the role of oxytocin during childbirth?
To stimulate the uterine muscles to contract
What is the primary function of the fight-or-flight response?
To prepare the body for extreme physical exertion
What is the primary function of the adrenal cortex?
To produce hormones in response to stress
Which hormone is released by the adrenal cortex and regulates sugar, fat, and protein levels?
Cortisol
What is the primary function of the pancreas?
To produce digestive enzymes
Which hormone is secreted by the hypothalamus and regulates growth and development?
Growth hormone-releasing hormone (GHRH)
What is the primary function of the pituitary gland?
To secrete hormones that regulate growth and development
Which hormone is released by the pineal gland and regulates sleep patterns?
Melatonin
What is the primary function of the hypothalamus-pituitary complex?
To link the nervous system to the endocrine system
What is the primary function of the anterior pituitary?
To secrete hormones that regulate growth and development
Where is the thymus gland located in the body?
In the upper chest behind the breastbone
What is the primary function of the thymus gland?
To train special white blood cells called T-lymphocytes or T-cells
What hormone is produced by the testes in large amounts?
Testosterone
What is the term for an overactive thyroid gland?
Hyperthyroidism
What type of hormone is produced by the ovaries in large amounts?
Estrogens
What is the term for a condition where the body produces too little insulin?
Diabetes
What is the term for an underactive thyroid gland?
Hypothyroidism
What is the purpose of a glucose tolerance test?
To measure the body's ability to regulate blood sugar levels
What is the term for a condition where the body produces too much insulin?
Hyperinsulinism
Study Notes
The Endocrine System
- The endocrine system consists of cells, tissues, and organs that secrete hormones as a primary or secondary function.
- The primary function of endocrine glands is to secrete hormones directly into the surrounding fluid, which is then transported by the blood vessels to reach the target cells.
Endocrine Glands
- The major endocrine glands include:
- Pituitary gland
- Thyroid gland
- Parathyroid glands
- Adrenal glands
- Pineal gland
- Thymus gland
- Ovaries and testes
- Some organs have both endocrine and non-endocrine functions, such as the pancreas, which produces digestive enzymes and hormones.
Hormones
- Hormones are chemical messengers that travel through the bloodstream to reach their target cells.
- Hormones can be classified into two major groups based on their chemical structure:
- Amino acid-derived hormones (amine hormones)
- Lipid-derived hormones (steroid hormones)
- Examples of amine hormones include epinephrine, norepinephrine, and melatonin.
- Examples of peptide and protein hormones include antidiuretic hormone (ADH) and atrial-natriuretic peptide.
- Examples of steroid hormones include testosterone and estrogens.
Pathways of Hormone Action
- Hormone receptors recognize molecules with specific shapes and side groups and respond only to those hormones that are recognized.
- The response triggered by a hormone depends on the hormone and the target cell.
- Hormone receptors can initiate signaling events or cellular mechanisms that result in the target cell's response.
Regulation of Hormone Secretion
- Hormone levels must be tightly controlled to prevent abnormal hormone levels and potential disease states.
- Feedback loops govern the initiation and maintenance of most hormone secretion in response to various stimuli.
- Positive feedback loops involve the release of additional hormones in response to an original hormone release.
- Negative feedback loops involve the inhibition of further secretion of a hormone in response to adequate levels of that hormone.
Organs of the Endocrine System
- Thyroid gland: produces triiodothyronine (T3) and thyroxine (T4) hormones, involved in regulating metabolism.
- Parathyroid glands: produce parathyroid hormone (PTH), involved in regulating blood calcium levels.
- Adrenal glands: produce steroid hormones involved in regulating stress response, blood pressure, and electrolyte balance.
- Pancreas: produces hormones such as glucagon and insulin, involved in regulating blood sugar levels.
- Hypothalamus: produces releasing hormones that regulate the synthesis and secretion of hormones from the pituitary gland.
- Pituitary gland: the "master gland" that produces hormones that regulate growth, development, and reproductive functions.
The Pineal Gland and Thymus Gland
- Pineal gland: produces melatonin, involved in regulating sleep patterns.
- Thymus gland: involved in the development and maturation of immune cells (T-lymphocytes).
Disorders of the Endocrine System
- Addison's disease
- Hyper and hypothyroidism
- Diabetes
- Dwarfism
- Gigantism
- Goiter
- Hyperinsulinism
- Hypoglycemia
Lab Tests
- Blood and urine hormone tests
- Fasting blood sugar
- Glucose tolerance test
- Thyroid function tests (T4, T3, TSH)
Discover the functions and components of the endocrine system, including the roles of ductless glands and hormones in the body.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
