Section 39.2 (Exam 3/4) Hormones Flashcards
The Endocrine System and Nervous System Work Together
What are the characteristics of neural signals?
Are very fast
Can rapidly communicate complex information
Can be turned off quickly
What are the characteristics of endocrine signals?
Are slow
Must diffuse and circulate; often act through cellular process such as protein synthesis
Responses are sustained
Describe the location, function, and structure of the pituitary gland.
attached to the hypothalamus of the brain
connects the nervous and endocrine systems
has two parts: anterior pituitary and posterior pituitary
Describe the anterior pituitary.
controlled by hypothalamic neurohormones that travel through portal blood vessels
Describe the posterior pituitary.
contains axons of hypothalamic neurons that release neurohormones
Hypothalamic neurons secrete 2 peptide neurohormones into the posterior pituitary. What are they?
Antidiuretic hormone (ADH) and oxytocin
Describe the function of antidiuretic hormone (ADH).
Increases the water retained by the kidneys when necessary
Also called vasopressin- it causes the constriction of peripheral blood vessels to elevate blood pressure
Describe the function of oxytocin.
Stimulates uterine contractions in childbirth and milk flow
The baby’s suckling stimulates neurons in the mother’s brain that cause secretion of oxytocin
What are the 4 tropic hormones which control other endocrine glands and are secreted by the anterior pituitary?
Thyrotropin (thyroid-stimulating hormone, TSH)
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Corticotropin (Adrenocorticotropic Hormone, ACTH)
What are the two gonadotropins?
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
What are the two things that growth hormones stimulate?
- stimulate cells to take up amino acids
- stimulate liver cells to produce signals to stimulate growth of bone and cartilage
What is a result of growth hormone overproduction or underproduction?
Gigantism or dwarfism
What are endorphins and enkephalins?
neuro-transmitters in the brain; natural painkillers
What is melanocyte-stimulating hormone (MSH) ?
stimulates production of melanin in skin and hair
What is the function of prolactin in humans?
mammary gland development and milk production
The hypothalamus does not extend neurons to the anterior pituitary. How does the hypothalamus control the anterior pituitary?
The hypothalamus produces releasing hormones that reach the anterior pituitary via the – portal blood vessels that run through the pituitary stalk
What are two examples of hypothalamic releasing hormones that can control the anterior pituitary?
Thyrotropin-releasing hormone (TRH)
Gonadotropin-releasing hormone (GnRH)
How do the endocrine glands control the anterior pituitary and the hypothalamus?
Using negative feedback, every time an endocrine gland releases hormones, some of them bind to the hypothalamus and some bind to the anterior pituitary, informing them that the hormone has been released, which stops the release of the releasing hormones.
What produces oxytocin, and what is oxytocin’s behavioral effect?
hypothalamus produces oxytocin
promotes bonding between mother and baby, and pair bonding in many animals, including humans
What would happen if oxytocin were blocked in new mothers?
new mothers would be struggle to breastfeed and bond with their baby
How can sex-hormones affect the nervous system?
strong influence on behavior (e.g. testosterone-aggression and anger)
What is the function of irisin?
mediate effects of exercise on the brain
many experiments show that exercise improves cognitive functions
