13.2 Hormonal Regulation Flashcards
What is the Pituitary Gland?
An endocrine gland that has two lobes and is about one size in diameter
Where does the Pituitary Gland sit?
In a bone cavity attached to the hypothalamus at the base of the brain
How many hormone does the Pituitary Gland release?
8 Hormones
What is the Pituitary gland controlled by?
The Hypothalamus through hormones and neurons that run through the connecting stalk
What are the two lobes of the Pituitary Gland?
The Anterior and Posterior
Which part of the Pituitary is part of the nervous system?
The Posterior Pituitary
What does the Posterior Pituitary do?
It does not produce hormones
It stores and releases the hormones ADH and oxytocin
Where are ADH and Oxytocin produced, and sent to?
They are produced in the hypothalamus and stored in the posterior pituitary
What hormones does the Anterior Pituitary store and release?
Human Growth Hormone (hGH) Prolactin (PRL) Thyroid-Stimulating Hormone (TSH) Adrenocorticotropic Hormone (ACTH) Follicle Stimulating Hormones (FSH) Luteinizing Hormone (LH)
How are hormones stimulated to be released from the Anterior Pituitary?
A series of blood vessels carries releasing hormones from the hypothalamus to the anterior pituitary
How does the Anterior pituitary regulate growth, development and metabolism?
Through the secretion of human growth hormone (hGH)
How does the Human Growth Hormone affect the body?
It increases
•Protein Synthesis
•Cell division and growth, especially cartilage, bone, and muscle
•Metabolic breakdown and release of fats stored in adipose (fat tissue)
What does hGH stimulate the growth of?
Muscles, connective tissue, and growth plates at the end of the long bones
What happens if the pituitary gland secretes excessive amounts of hGH during childhood?
It can result in a condition called gigantism
What happens if there is insufficient hGH production during childhood?
Dwarfism
What happens when someone reaches adulthood and hGH is overproduced?
A condition called acromegaly which widen the bones, soft tissue. It also causes cardiovascular disease, sugar intolerance, diabetes, breathing problems, muscle weakness, colon cancer
Where does the Thyroid Gland sit?
Directly below the larynx
What hormone is produced in the Thyroid?
Thyroxine T4
What does Thyroxine do?
Increases the rate at which the body metabolizes fats, proteins, and carbohydrates for energy
What organs does Thyroxine especially stimulate and what does it do?
Heart, skeletal muscles, liver, and kidneys increases the rate of cellular respiration
How does Thyroxine play an important role in the growth and development of children?
It influences the organization of various cells into tissues and organs
What happens if the thyroid fails to develop properly during childhood?
A condition called cretinism can result and the thyroid produces less that normal thyroxine. This is called hypothyroidism
What are the symptoms of people with hypothyroidism?
Shorter than average, stocky, tiredness, slow pulse rate, puffy skin, hair loss, weight gain
What are the symptoms of Hyperthyroidism?
Anxiety, insomnia, heat intolerance, irregular heartbeat, weight loss
What is graves disease?
A disease where the body’s immune system attacks the thyroid
What are the symptoms of Graves of disease?
Swelling of the muscles around the eyes
What is Thyroxine production controlled by?
Negative feedback
What hormone does the Anterior pituitary release that controls thyroid secretion?
Thyroid Stimulating Hormone (TSH)
What does the thyroid require in order to make Thyroxine?
4 molecules of iodine
What happens if there is insufficient iodine in the diet?
thyroxine cannot be made and there will be no signal to stop the secretion of TSH
What happens if there is non-stop stimulation of the thyroid?
Goiter which is the enlargement of the thyroid
What are calcium levels in the blood regulated by?
A hormone called Calcitonin
What happens when the concentration of calcium in the bones is too high?
Calcitonin stimulates the uptake of calcium into bones
What are the Parathyroid glands?
Four small glands attached to the thyroid
What hormone do the parathyroid glands produces?
Parathyroid hormone
What does the Parathyroid hormone do?
Stimulates bone cells to break down material and reabsorb calcium into the blood
How does the Parathyroid hormone affect kidneys?
It stimulates the kidneys to reabsorb calcium from urine, and activates vitamine D. Vitamin then stimulates the absorption of calcium from the food in the intestine
