Chapter 17: Endocrine System Flashcards
What does exocrine gland mean?
Glands releasing their products into the ducts
What does endocrine gland mean?
Glands releasing their products into the interstitial fluid
What are the examples of endocrine glands?
Pituitary, Thyroid gland, Parathyroid gland, Adrenal gland, Pineal gland
What are the organs that are with endocrine cells?
Hypothalamus
Thymus
Pancreas
Ovaries
Testes
Kidneys
Stomach
Liver
Small intestine
Skin
List the functions of hormones
- Help regulate chemical composition and volume of internal environment (interstitial fluid), Metabolism and energy balance, Contraction of smooth and cardiac muscle fibers, Glandular secretions, Some immune system activities
- Control growth and development
- Regulate operation of reproductive systems
- Help establish circadian rhythms
What are 2 types of hormones?
- Water-soluble hormone 2. Fat-soluble hormone
What is the target of hormones?
Target of hormones is the specific target cell although they flow through blood to all cells
What is the example of lipid soluble hormones?
Steroids, thyroid hormones, and nitric oxide
How does lipid soluble hormones affect the cell function?
They affect cell function by altering gene expression
What is the example of water soluble hormones?
Modified amino acids, peptides, and proteins
What does water soluble hormones do?
Water soluble hormones alter the cell function by activating plasma membrane receptors, produce a second messenger, and activates various protein inside the cell
What is hormone secretion controlled by?
Signals from the nervous system, chemical changes in the blood, and other hormones
What produces hormones?
Hormones produced by hypothalamus regulating pituitary gland
What level is the hypothalamus at in terms of endocrine control?
Highest level of endocrine control
What does hypothalamus do?
Hypothalamus regulates the nervous and endocrine activity, hormones such as ADH/oxytocin, and control of sympathetic output to adrenal medullae
What protects the pituitary gland?
Pituitary gland is protected by the sella turcica (sphenoid bone)
What connects hypothalamus and pituitary
Hypothalamus and pituitary are connected by infundibulum, containing axons and blood vessels
What does anterior pituitary do?
Makes hormones when stimulated by hypothalamus tropic hormones
What forms hypophyseal portal vessels?
Capillaries form the hypophyseal portal vessels
What are hypophyseal portal vessels?
Direct blood connection between hypothalamus & anterior pituitary
What does posterior pituitary do?
Posterior pituitary stores hormones made by the hypothalamus (in axon terminals) such as oxytocin and ADH
What regulate activities from growth to reproduction?
Posterior pituitatry
What does secretion of posterior pituitary do?
Release/inhibit hormones
From what do hormones of posterior pituitary become transported?
hypophyseal portal veins
List the examples of hormones from anterior pituitary
Human growth hormone (GH)
Thyroid‐stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Follicle‐stimulating hormone (FSH)
Luteinizing hormone (LH)
Prolactin (PRL)
Melanocyte‐stimulating hormone (MSH)
What does growth hormone do?
Stimulates cell growth – protein synthesis, breakdown of fatty acids – ‘glucose‐sparing effect’, and act on all cells – major target is bones and skeletal muscles
What is acromegaly?
Disorder of growth hormone which cause thicken in bones of hands, cheeks, jaws, and feet
What does thyroid-stimulating hormone (TSH) do?
Development and secretions of thyroid gland, controlled by hypothalamus
What does Adrenocorticotropic hormone (ACTH) do?
They act on adrenal cortex and stimulate glucocorticoids to assist in glucose metabolism
What does follicle-stimulating hormone of Gonadotropins do?
Females: maturation of eggs
It works with LH
Males: stimulate sperm production
What does luteinizing hormone (LH) do?
Females: Maturation of eggs
Most responsible for ovulation
Males: stimulate production of testosterone
What does prolactin (PRL) do?
Stimulate milk production by the breasts
What does Melanocyte‐Stimulating Hormone (MSH) do?
Increase skin pigmentation but not active in normal adults
Does posterior pituitary synthesize any hormones?
No, they only secret hormones
What is oxytocin involved in?
Uterine contractions, milk ejection in nursing mothers
Emotional bonding, love, empathy, and feeling socially connected.
What is Antidiuretic hormone (ADH) also called and involved in?
Antidiuretic hormone is also called vasopressin
Causes kidneys to reabsorb water and vasoconstriction to increase blood pressure when blood volume is low
What is diuretic?
Diuretic means it increases water excretion
What are parts of thyroid gland?
Right/left lobe, isthmus, and thyroid follicles
What are thyroid follicles?
Large, microscopic, spherical sacs within thyroid and follicular cells in the walls of the follicles produce a precursor
What is thyroglobulin?
Precursor to two thyroid hormones which are thyroxine (T4) or tetraiodothyronine (T4) and triiodothyronine (T3)
What element does thyroglobulin require?
Iodine required in diet to produce them
What are thyroid hormones (T4 and T3)?
They are permeable to membranes of many cells and major metabolizer (activate genes to synthesize enzymes for ATP production, regulate oxygen use and metabolic rate, growth and development)
What does Hypothyroidism cause?
Lethargic, Intolerance to cold, Dry skin, Low BMR, Weak muscles, and “myxedema”
What does hyperthyroidism cause?
Increase BP and HR, CNS: restless; irritable: moody
Where are parafollicular cells and what do they do?
Parafollicular cells located between the follicles and they produce calcitonin
What does Calcitonin (CT) do?
It decreases blood calcium levels
Where do CT act on?
They act on bone and kidney (Inhibit osteoclasts and stimulate excretion)
Is CT direct or indirect?
CT is direct, no involvement of hypothalamus or pituitary and respond directly to calcium levels
What is the relationship between CT and parathyroid hormone?
CT is antagonist to parathyroid hormone
Where is parathyroid hormone (PTH)?
Parathyroid hormone is secreted by the parathyroid glands which are 4 glands loacted on the thyroid
PTH is important to what?
Parathyroid hormone is critically important to regulation of calcium levels
What are the effects of parathyroid hormone?
Parathyroid hormones decrease blood phosphate levels and increase blood calcium
levels
Where do parathyroid hormone act on?
Skeletal bone: Osteoclasts: breakdown bone and release Ca+ and phosphate into blood, Inhibit osteoblasts
Intestines and: Reabsorption of calcium from food-Need vit D
Kidneys: Tubular reabsorption of Ca+, Excrete phosphate
What is the location of Adrenal Glands
Superior surface of each kidney
What is the structures for adrenal glands?
Outer cortex and Inner medulla
What are Corticosteroids?
Steroid hormones and has 3 groups of hormones
What are 3 groups of hormones for corticosteroids?
- Mineralocorticoids
- Glucocorticoids and
- Gonadocorticoids (sex hormones)
What is aldosterone?
Primary mineralcorticoids
What does aldosterone do?
They increase sodium and water reabsorption and decrease potassium reabsorption.
Secretion is controlled by the renin–angiotensin–aldosterone pathway
What is cortisol?
Primary glucocorticoids
What does cortisol do?
They promote normal metabolism, help resist stress, and decrease inflammation.
Secretion is controlled by ACTH
What is the Androgens?
Main part of gonadocorticoids(sex hormones) which Secreted by the adrenal cortex, stimulate growth of axillary and pubic hair,Aid the pre‐puberty growth spurt, and
contribute to libido
What stimulates adrenal medulla?
Adrenal medulla is stimulated by sympathetic nervous system
What does adrenal medulla secrete?
They Secretes two hormones into bloodstream which are epinephrineand norepinephrine
Where do adrenal medulla act on?
They act on many tissues, Same effects as NE neurotransmitters released by sympathetic postganglionic neurons = stress response
What is the process of stress reponse?
Stress & exercise>Impulses from hypothalamus> preganglionic
neurons>Adrenal medullae>epinephrine and norepinephrine>Fight or flight response
What comes after fight or flight reponse? (List the process)
Increase heart rate > increased blood pressure>Increased blood flow to muscles, heart, liver, adipose tissue > Dilate airways to lungs > Increase levels of glucose and fatty acids in blood
What is endocrine portion of pancreas?
Endocrine portion of pancrease is Islets of Langerhans:
Alpha cells secrete glucagon
Beta cells secrete insulin
What does exocrine portion of pancreas do?
Releases enzymes into duodenum, Acini cells in the tissue surrounding the islets of Langerhans, and Secrete digestive enzymes through pancreatic duct
What is insulin?
Main glucose level regulator
What does insulin do?
Breaking it down for energy or convert to fat for storage & Inhibits breakdown of glycogon to glucose
What is the disorder of insulin?
Diabetes Mellitus ‐ without insulin, blood levels of glucose will increase
What does glucagon do?
Raises blood glucose level: Accelerate breakdown of glycogen into glucose in
liver, Release glucose into blood, and Insulin is the main regulator, so there are no
reported disorders for hyper or hyposecretion of glucagon
What is estrogen of ovaries?
Estrogen promotes secondary sex characteristics and stimulates uterine growth in preparation for pregnancy
What is Progesterone of ovaries?
Important for fetal development and if no pregnancy, progesterone decreases and triggers menstruation
What is Inhibin of ovaries?
Inhibits secretion of follicle‐stimulating hormone (FSH)
What is Relaxin of ovaries?
Increases flexibility of pubic symphysis during pregnancy and helps dilate the uterine cervix during labor and delivery
What is Testosterone of testes?
Development of reproductive tissues during embryonic development
Development of secondary sex characteristics(increase bone and muscle mass)
Fertility
