Endocrine System Flashcards
what are the 7 functions of the endocrine system?
- metabolism, control of food intake, digestion
- tissue development
- ion levels and water balance
- heart rate and blood pressure changes
- control of blood glucose and other nutrients
- control of repro functions, uterine contractions, and milk release
- immune system functions
list and describe the 3 classes of hormones based on what they are derived or synthesized from
- amines: from amino acid tyrosine, one amino acid long
- peptides: chains of amino acids, shorter than proteins
- steroids: synthesized from cholesterol
do all three classes of hormones signal the same way?
no
list and describe the 3 modes of transmission in the endocrine system
- endocrine: hormone travels through bloodstream to its target
- paracrine: hormone acts locally on nearby cells, no blood travel, stays in tissue/organ
- autocrine: hormone acts on the cell that secreted it
what are target cells and how many does each hormone have?
cells affected by a given hormone, some hormones have many and some only have 1
list and describe the two modes of hormone recognition of a target cell
- bind to receptors on the surface/outside of cell membrane: hormone is never internalized, peptide hormones do this
- bind to receptors within the cell: hormones diffuse through the cell membrane
list and describe the 2 types of hormone regulation
- negative feedback (most common):rising levels of a hormone in the bloodstream result in a biological response which will then inhibit further release of that hormone
- positive feedback (mostly in repro): rising levels of a hormone in the bloodstream result in a biological response which then causes further release of that hormone
give an example of negative feed back
insulin regulating blood glucose levels
give an example of positive feedback
cervical dilation during parturition releases oxytocin which causes further cervical dilation
what are the 6 major endocrine glands?
- Posterior pituitary
- anterior pituitary
- thyroid
- parathyroids
- adrenals
- pancreas
where is the posterior pituitary gland located?
on the caudal side of the pituitary gland
list and describe the hormones the posterior pituitary gland releases
- antidiuretic hormone (ADH): is a peptide, does water conservation; acts on renal tubules to increase water reabsorption and allows for water retention, urine concentration
- oxytocin: is a peptide, stimulates milk letdown and uterine contractions, males can produce it they just don’t need to
what is the anterior pituitary gland also called, how many hormones does it secrete, and where is it located?
the master gland, 7 hormones, and on the cranial side of the pituitary gland
list the 7 hormones secreted by the anterior pituitary gland
- growth hormone (somatotropin)
- adrenalcorticotropic (ACTH)
- thyroid stimulating (TSH)
- Beta-lipoprotein (B-LPH)
5-6 (Gonadotropic hormones) - Follicle stimulating (FSH)
- luteinizing hormone (LH)
- prolactin
describe growth hormone (somatotropin)
a peptide that stimulates growth and cell division, causes release of nutrients for energy and growth, most body cells are target cells
describe adrenalcorticotropic hormone (ACTH)
a peptide that stimulates the adrenal cortex to release hormones
describe thyroid stimulating hormone (TSH)
a peptide that stimulates the thyroid to release thyroid hormone
describe Beta-lipoprotein hormone (B-LPH)
a peptide that might have a role in pain relief
describe follicle stimulating hormone (FSH)
a peptide that stimulates oogenesis in females and spermatogenesis in males
describe luteinizing hormone (LH)
a peptide that stimulates ovulation in females and testosterone production in males
describe prolactin
a peptide that promotes, initiates, and maintains lactation
how many hormones (and what classes) are secreted by the thyroid gland?
2, thyroid hormone is an amine, and calcitonin is a peptide
describe the different forms and function of thyroid hormone
an amine whose release is stimulated by TSH, T4 has 4 iodines and is the inactive form, the target cells remove an iodine to create T3, the active form which results in increased heat production and an increase in oxygen consumption, increasing overall metabolism
where all is iodine found in the body?
only in thyroid hormone
describe the function of calcitonin
a peptide released due to high levels of blood calcium, TONES down blood calcium (lowers levels)
where are the parathyroid glands located?
embedded in the back of the thyroid
how many parathyroid glands do animals have and how many hormones do they secrete?
animals have pairs, either 1 or 2, and they secrete one hormone, parathyroid hormone
describe parathyroid hormone
a peptide that works with calcitonin to regulate calcium, released due to low blood calcium levels, acts to raise blood calcium concentrations
where are the adrenal glands located?
on the cranial side of the kidney
describe the 2 parts of the adrenal glands
- outer cortex: outer portion, secretes corticosteroids, which are steroid hormones
- adrenal medulla: inner portion, secretes catecholamines, which are amine hormones
what are the two types of corticosteroids that the adrenal cortex secretes?
glucosteroids and mineralocorticoids
describe glucosteroids (two examples and function)
cortisol, corticosterone, steroids that increase glucose synthesis, release is stimuled by ACTH, allow for an increase inn energy available for stressed cells
describe mineralocorticoids (2 hormones and function)
epinephrine and norepinephrine, amines that prepare the body for fight/flight by raising heart rate, blood glucose, and fat
when the pancreas is acting in an endocrine fashion, how many hormones does it secrete?
2 peptides: insulin and glucagon
describe the function of insulin
a peptide secreted when blood glucose concentrations are high, acts to lower blood glucose
describe the function of glucagon
a peptide that raises or maintains blood glucose
