Kill Myslef Flashcards
What do the exocrine glands do and what are the parts
Secrete substances through ducts or tubes onto a body surface or into a cavity
Salivary glands
Prostate gland
Milk glands
What are endocrine hormones and how are they classified?
chemicals secreted by endocrine glands directly into the blood
classified according to their activation site
What do non-target hormones affect?
affect many cells throughout the body; eg. insulin, epinephrine, GH, somatotropin.
What do target hormones affect?
affect specific cells or target tissues; eg. parathyroid hormone, gastrin
What do endocrine hormones not affect?
Do not affect all cells - only cells with receptors for that target cell.
2 types of hormones
Steroid Hormones & Protein Hormones
Steroid Hormones: what are they made of? What are (not) soluble in? Examples?
made from cholesterol - complex rings of C, H, O
Not soluble in water, but ARE soluble in fat (can dissolve across cell membranes)
eg. Sex hormones, cortisol (stimulates conversion of aas to glucose by the liver).
Steroid hormones: what do they diffuse from? What do they combine with and where?
Diffuse from capillaries to target cell
Combine with receptors in cytoplasm
How do steroid hormones do protein synthesis?
- Hormone/receptor complex moves across membrane to nucleus
- Attaches to chromatin with complementary shape
promotes or blocks transcription of a specific gene - Activates a gene that will initiate protein synthesis
Protein hormones: what do they contain? What are the soluble in? Examples?
Contain chains of amino acids
soluble in water
eg. insulin and growth hormone
Protein Hormones: What do they combine with and where?
Combine with receptors on cell membrane
What do Protein hormones do in protein synthesis? What is cAMP?
- Activates production of adenylyl cyclase
- Causes cell to convert ATP to cAMP
cAMP is a messenger – activating enzymes in cytoplasm to carry out their normal functions
What is the pituitary gland? What does it do? What is it connected to?
The ‘master’ gland
Exercises control over endocrine glands
Connected to hypothalamus
What does posterior lobe do?
stores and releases hormones that have been made in the hypothalamus (i.e. ADH and oxytocin)
What does Anterior lobe do?
produces its own hormones
hypothalamus nerves regulate their release
Where is the pancreas located? What functions does it have? What does it secrete?
located in the folds of the duodenum
has both endocrine and exocrine functions
secretes several key digestive enzymes
What are Islets of Langerhans? What do they have?
Specialized tissues in which the endocrine functions of the pancreas occurs
Have alpha (α), beta (β) and delta (δ) cells – each one secretes a hormone
What is glucagon secreted by and when? What does it do?
secreted by α cells when blood glucose levels ↓
Stimulates liver to
release glucose stores (glycogen to glucose) to blood
Make glucose (gluconeogenesis)
Glucagon: trigger, target & effect
Trigger: low glucose, sympathetic nervous system
Target: liver (mostly), adipose, muscles
Effect: breaks glycogen down into glucose
What is insulin secreted by? What do the cells take up?
Secreted by β cells when blood glucose levels ↑
Antagonistic to glucagon
↑ the rate cells take up glucose (thus lowers blood glucose)
Insulin: trigger, target & effect
Trigger: high glucose, food intake, GI hormones
Target: liver, adipose, muscles
Effect: stores glucose in tissues (glycogen), converts aa’s to pr-
Flow chart for glucagon
Stimulus (low blood glucose) -> monitor sensor (chemoreceptors in hypothalamus) -> coordinating center (hypothalamus triggers pancreas to release glucagon to blood) -> regulators effector (liver - converts glycogen to glucose) -> response (increased blood glucose)
Flowchart for insulin
Stimulus (high blood glucose) -> monitor sensor (chemoreceptors in hypothalamus) -> coordinating center (hypothalamus triggers pancreas to release insulin to blood) -> regulators effector (body cells - permeable to glucose, liver & muscle - convert glucose to glycogen) -> response ( lower blood glucose)
What is somatostatin secreted by? What does it do?
secreted by δ cells
inhibits effects of glucagon and insulin and many other hormones such as GH, TSH and gastrin
What is diabetes mellitus caused by and what are the complications?
Caused by insufficient production of insulin by β cells in pancreas
Complications:
Blindness, kidney failure, nerve damage, limb amputation
Where are adrenal glands located and what are the 2 divisions?
Located above each kidney
2 Divisions: Adrenal Medulla & Adrenal Cortex
What is the adrenal medulla regulated by? What are they stimulated by? What do they cause?
Regulated by nervous system
Stimulated by nerves during times of stress to produce epinephrine and norepinephrine
cause blood sugar levels to rise which ensures more E is available to tissues
What is the adrenal cortex regulated by? What do they secrete?
Regulated by hormones
Secretes 3 classes of steroid hormones:
Glucocorticoids (~95%)
Mineralocorticoids
Androgenic hormones
Adrenal cortex: glucocorticoids account for what? What do they do?
Account for 95% of the hormones made in the adrenal cortex
i.e. Cortisol
↑ level of aa’s in blood (will be converted to glucose) to help body recover from stress
Flowchart for adrenal medulla
Stimulus (short term stress) -> monitor (hypo receptors in spinal cord) -> coordinating center (Trigger adrenal medulla to secrete epinephrine and norepinephrine) -> response (↑ blood glucose,↑ HR, BR, cell metabolism,↑ blood flow to heart and muscle cells)
What is flight or fight response initiated by? What are the effects on body?
Initiated by norepinephrine
Increases HR and blood sugar – ensures E is available
Blood vessels dilate – allows more O2 and nutrients to reach tissues
Iris dilates – allows more light to reach retina – gives your body as much visual info as possible
Flowchart for adrenal cortex
Stimulus (long term stress) -> monitor sensor (receptors in hypothalamus) -> coordinating center (Triggers ant. pit. 🡪 ACTH 🡪 adrenal cortex 🡪 mineralocorticoids (aldosterone)& glucocorticoids (cortisol). -> regulators effector (liver - converts aa to glc & fats to f.a., Kidneys - ↑ Na+ reabsorption) -> response (↑ blood glucose & BP)
Where is the thyroid gland located
located at the base of neck
below larynx, in front of the trachea
What does the thyroid gland produce?
Produces hormones thyroxine (T4) and triiodothyronine (T3) (iodine is an important component of both)
Thyroid gland: trigger, target & effect
Trigger: low MR or cold 🡪 TSH
Target: many tissues
Effect: Increase metabolism, protein synthesis, production of ATP
Thyroid gland produces what? What is its Trigger, target & effect?
Produces hormone CALCITONIN
Trigger: increased blood calcium
Target: bone
Effect: deposit calcium in bone
What are parathyroid glands? Where are they located? How many? What do they do?
small, pea-shaped glands
located in neck near the thyroid
usually 4 – but number can vary
regulate level of calcium in body
What do parathyroid glands produce? What is its trigger, target and effect?
Produce parathyroid hormone (PTH)
Trigger: Low level of calcium in blood
Target: bone, kidney, intestine
Effect: reabsorb calcium into blood
Flowchart for parathyroid
Stimulus (high blood calcium) -> monitor sensor (chemoreceptors in blood) -> coordinating center (Parathyroid – inhibits PTH, Thyroid – releases calcitonin) -> regulator effector (Kidneys - ↑ Ca2+ in urine, Bones – Ca2+ deposited) -> response (↓ blood calcium)
Flowchart for parathyroid (low)
Stimulus (low blood calcium) -> monitor sensor (chemoreceptors in blood) -> coordinating center (parathyroid releases pth) -> regulators effector (Kidneys - retain Ca2+ , Intestine – retain Ca2+, Bones – release Ca2+ ) -> response (↑ blood calcium)
What are thyroid disorders?
Inadequate levels of thyroid hormones can cause hypothyroidism or myxedema.
Thyroid disorders: Myxedema Symptoms
Facial bloating
Weakness
Cold intolerance
Dry skin
Weight gain
Goiter (excess TSH)
Thyroid disorders: Myxedema Symptoms
Facial bloating
Weakness
Cold intolerance
Dry skin
Weight gain
Goiter (excess TSH)
What does the overproduction of thyroid hormones lead to? What are they commonly called?
overproduction of thyroid hormones results in hyperthyroidism
commonly called Graves disease
Symptoms of thyroid disorders, what does long term hyperthyroidism cause?
Insomnia, fatigue
Hypertension
Weight loss
Heat intolerance
Long term hyperthyroidism causes exopthalmos – bulging of eyeballs
How does nervous system and endocrine system adapt to stress?
Nervous system ↑ heart rate and diverts blood to the needed muscles
Endocrine system is slower, but provides the more sustained response of hormone release
Stress hormones provide more blood glucose to deal with what
Stress hormones provide more blood glucose to deal with increased E requirements, increased BP and blood volume.
In response to stress… (Epinephrine)
Epinephrine Increases
Mobilizes CHO and fat stores
↑ blood glucose and fatty acids
Accelerates HR and the activity of the respiratory system
In response to stress… (cortisol)
Cortisol Increases
Mobilizes E stores by converting pr- to glucose
Elevates blood aa’s, blood glucose and blood fatty acids
In response to stress… (glucagon & insulin)
Glucagon Increases
Converts glycogen to glucose
Insulin Decreases
Decreases breakdown of glycogen in liver
(Stress hormones) Epinephrine - change & adjustment
Increases
-Mobilizes carbohydrate and fat energy storage
-increases blood glucose
-accelerates heart rate and activity of respiratory system
(Stress hormones): cortisol - change, adjustment
Increases
-mobilizes energy stores converting protein to glucose
-elevates blood amino acid, glucose and fatty acids
(Stress hormones): glucagon - change, adjustment
Increases
Converts glycogen to glucose
(Stress hormones): insulin - change, adjustment
In response to stress
-decreases breakdown of glycogen in the liver
During athletic competition…
the responses of the body to stress provide more ATP to run muscles, etc.
During emotional or psychological stress…
the ↑ ATP is not always used and the ↑ blood glucose, blood pressure and metabolic rate can cause problems for the body.
What are problems with long term stress
High Blood Sugar
↑ blood pressure
↑ water loss from nephron
High Blood Pressure
Blood vessel rupture
↑ blood clotting
Increased Heart rate
can lead to higher blood pressure
possible destruction of heart muscle
What are prostaglandins? How are they released? And how are they secreted?
Hormones that have an effect on a small localized area of cells.
Released in response to changes in the immediate environment of a cell.
Secreted in low amounts by mediator cells, absorbed rapidly by surrounding tissue.
How many types of prostaglandins are there? What do they do?
16 different types – alter cell activity to counteract or adjust for a change
Prostaglandins responses to stress
stimulated by epinephrine release, PG’s ↑ blood flow to local tissues
trigger relaxation of smooth muscle in respiratory passages
also released during allergic reactions
How can drugs that mirror hormones affect the body?
Some drugs can mirror hormones produced by the body to affect heart rate, breathing and blood pressure (i.e. Caffeine produces similar effects to epinephrine).
Pituitary gland
Controls all other endocrine glands; influences growth metabolism and regeneration.
Hormones: oxytocin, ADH, TSH, ACTH, FSH, LH, GH, PRL
parathyroid
Secretes the hormones necessary for calcium absorption.
Hormone: PTH (parathyroid hormone)
Adrenal glands
Secretes hundreds of compounds including cortisone & adrenaline which helps you react to emergencies. Regulates your metabolic processes in the cells, water balance, blood pressure etc.
Hormones: adrenaline (epinephrine), Noradrenaline (norepinephrine), androgen, glucocorticoids
Hypothalamus
Regulates hunger, thirst, sleep and wakefulness plus most of your involuntary mechanisms including body temperature.
Hormones: GHRN, TRH, Somatostatin
Thyroid glands
Regulates your energy and your metabolism.
Hormones: T3, T4, calcitonin
Pancreas
Aids in the digestion of protein, fats and carbohydrates. Produces insulin which controls blood sugar levels.
Hormones: insulin, glucagon
Ovaries
Influences how your blood circulates and determines your mental vigor and your sex drive (testes in males).
Hormones: estrogen & progesterone (involved in periods), testosterone, FSH
