Endocrine System Flashcards
Define hormones.
-small Chemical compounds produced by endocrine cells or glands
Describe the Characteristics of hormones.
- release into blood and travel throughout body
- Reach a target cell and produce a response
- same hormones can have a different effect depending on the cells they reach
- some hormones only release under specific circumstances
- some hormones are always circulating
What are the functions of hormones?
- regulate chemical composition of body fluids
- control glandular secretions
- control metabolism
- involved in immunity
- regulate reproduction
- regulate growth and development
List the endocrine organs
- Hypothalamus
- Pituitary Gland
- anterior
- posterior
- Thyroid
- Adrenal Gland
- Pancreas
- Gonad
- testes
- ovaries
what is the Hypothalamus
Region of the brainstem that receives info from nervous system and endocrine system and can respond by releasing hormones
What organ does the hypothalamus hormones act on?
- anterior pituitary gland
- stimulates posterior pituitary to release it’s hormones
What is another name for hypothalamus and why?
- master endocrine organ
- it controls the release of other hormones
Describe the structure of the pituitary gland
- marble sized gland and base of the brain
- divided into anterior and posterior lobes
What is the role of the pituitary gland?
-receives info from the hypothalamus
What is the role of the anterior pituitary gland
-produces growth hormones
what is growth hormone?
-affects cells by increasing protein synthesis
What is the role of posterior pituitary gland
releases ADH (antidiuretic hormones)
what is ADH?
- antidiuretic hormone
- targets kidneys causing water reabsorption
- maintains blood volume and pressure
Where are the thyroid glands located
-Anterior surface of the trachea
What is the role of the thyroid gland
Produces thyroid hormones
What is the function of thyroid hormones?
- regulates metabolism
- targets heart, muscles, liver, and kidneys
- controls heat production
What substance does the hormones of the thyroid contain
-iodine
Describe the adrenal glands
-pair of glands located above the kidneys
what are the 2 regions that make up the adrenal glands
- inner adrenal medulla
- outer adrenal cortex
How does the adrenal medulla work?
- receives signal from nervous system
- produces 2 hormones
- Epinephrine (adrenaline)
- norepinephrine (noradrenaline)
when are adrenal medulla hormones secreted?
- in response to stress (good or bad)
- yields the flight or fight response
What stimulates the adrenal cortex
-stress
What hormone is produced by the adrenal glands
-steroid hormone
what is cortisol?
- hormone produced by adrenal cortex
- promotes conversion of protein and fat into glucose
- becomes available as fuel for flight or fight
- reduces inflammation temporarily to allow fight or flight with an injury
What two body systems does the pancreas work with
- Exocrine or digestive system
- Endocrine functions
Describe the exocrine function of the pancreas
-production of pancreatic juice which releases into pancreatic duct and small intestine
what substances does the pancreatic juice contain?
- digestive enzymes
- bicarbonate ions
Describe what carries out the endocrine functions of the pancreas
- small groups of cells called pancreatic islet cells
- in-dispersed within many exocrine cells
What are the 2 hormones secreted by the pancreas
- insulin
- glucagon
Describe the role of insulin
- secreted when blood glucose level are high
- causes blood glucose to be taken up by metabolically active cells
- causes glucose to be converted into glycogen to increase blood glucose levels
describe the role of glucagon
- secreted when blood glucose levels are low
- causes glycogen in liver t be converted into glucose to increase blood glucose levels
What is diabetes mellitus?
-a disorder with a decrease in insulin production or activity
what are the 2 types of diabetes mellitus?
- Type 1
- type 2
Describe type 1 diabetes mellitus
- autoimmune destruction of insulin producing cells
- body loses ability to use glucose in cells because insulin is not present in the blood
- body uses cellular stores of protein and fat as energy
- increase glucose levels means urinate glucose, water follows due to osmosis
- managed by insulin injections
Describe type 2 diabetes mellitus
-Insulin is produced however is not picked up by cell receptors
what is the cause of type 2 diabetes
-faulty insulin production or a decrease in activity of insulin receptors on cells of the body
How is type 2 DM managed
- diet
- carb restriction
What are gonads
- Testes and ovaries
- site of gamete production
- hormone production for development and maintenance of secondary sex characteristics
- hormones produced also play role in behaviour
Describe testes
- paired, external structures found in males
- produces sperm cells
What hormones do testes produce
-androgens such as testosterone
What is the role of testosterone?
- in embryo - determines gender as male
- in puberty: develops facial hair, voice changes, increase muscle mass, sperm production
Describe ovaries
-paired structures in female that produce ova or eggs
what hormones do ovaries produce
- estrogens
- progesterone
What is the role of estrogens and progesterones?
at puberty
- development of egg maturation and the ventral cycle prepared uterus for possible pregnancy
- play role in pregnancy and lactation
