Unit 1 endocrine system (hormones) Flashcards
Adrenocorticotropic hormone function after released
protects the body in stress situations (pains and injuries)
Growth hormone
leads to physical growth
increases metabolism, cell size, bone and muscle growth, promotes healing and tissue repair
Thyroxine hormone function
increases metabolic rate, increased breakdown of fats and carbohydrates, affects protein metabolism, synthesis of sodium potassium pumps, and is involved in the development of nervous and skeletal system
calcitonin hormone function (thyroid)
regulated by negative feedback of calcium ion levels in the blood
reduces blood calcium and phosphate levels
parathyroid hormone
raises calcium blood levels
regulated by negative feedback of calcium ion levels
Adrenal cortex: outer zone: aldosterone
Outer zone produces mineralocorticoids (steroids of salt and water balance)
Aldosterone: reabsorption of Na+, leading to increased water reabsorption and execration K+, H+ from the kidney
Adrenal cortex middle zone: cortisol
Middle zone: produces glucocorticoids (steroid hormone produced from the adrenal glands)
Cortisol: stimulated by the anterior pituitary, responds to stress, increases muscle metabolism, increases sugar storage via gluconeogenesis, other effects
Adrenal cortex inner zone: androgens
Inner zone: produces androgens
In male and female is the primary source until puberty when sex glands take over involved in the development of secondary sex characteristics
Adrenal Medulla: Epinephrine (adrenaline) and Norepinephrine (noradrenaline)
Both are neurotransmitters that respond to fear, excitement, and danger
Both hormones increase blood pressure
Epinephrine increases blood flow to the heart and muscles
Norepinephrine decreases blood flow to the intestines and the skin
Pancreas: glucagon glucose is high
Produced by beta cells
Lowers blood glucose levels
hypoglycemia
Increasing cellular glucose uptake through cells
causes low blood sugar levels
Pancreas: insulin glucose is low
Produced by beta cells
hyperglycemia
Increases blood glucose levels
stimulates glucagon to the liver to make glucose
high blood sugar levels
loss of blood glucose level control
Diabetes mellitus
* Loss of insulin
* No uptake of glucose (leading to hyperglycemia)
* Leads to ketoacidosis
“exhausted”
* Hyperinsulinemia
Leads to hypoglycemia
Symptoms: anxiety, sweating, tremors, increased heart rate
Leads to unconsciousness, coma
Thymosins- Thymus glands
Secretes thymosin (hormone)- involved in the development of the immune system
Larger as a baby and decreases in size as age ^
Pineal gland
Secretes melatonin – acts on the hypothalamus to change levels of luteinizing hormone
Also responds to light and may be related to daily rhythms
Homeostasis
Homeostasis is the process by which the body maintains a stable internal environment, such as temperature, pH, and fluid balance, despite changes in external conditions. It ensures that the body’s systems function properly.
Stress = any stimulus that leads to an imbalance to
homeostasis
* External: eg. heat, cold, loud noise
* Internal: eg. pain, emotion, increased blood pressure
adaptation
Body must adapt and regain homeostasis through negative feedback; goes back to normal
endocrine vs nervous system
Nervous system: releases neurotransmitters, which acts locally (nerve, muscle, glands), slow acting, and long lasting
Endocrine system: releases hormones, which act at distant location around body, slow acting, long lasting
Dealing with stress (phases)
Alarm phase
Sympathetic Nervous system stimulated fast
Fast acting but short lived
Resistance
Endocrine system kicks in
Long lasting but needs time to get started
Exhaustion phase
Endocrine system breaks down
Hormone no longer works
Organ failure (irritable bowel syndrome, tumors, hypertension, depression)
blood calcium levels
Calcium is mostly stored in the bone
Needs some circulating calcium for:
Blood clotting
Release of neurotransmitters
muscle contraction
Normal heartbeat
Normal function, need a constant blood calcium level
control of blood calcium levels: calcitonin produced by thyroid gland
Released from thyroid gland when
blood calcium levels increase
Works to decrease blood calcium levels
to physiological conditions by:
-Stimulating osteoblasts to absorb calcium to make bone
-Reducing osteoclast activity
Control of blood calcium levels: parathyroid
Released from parathyroid gland when
blood calcium levels decrease
* Works to increase blood calcium levels to physiological conditions by:
-Inhibiting osteoblasts
-Stimulating osteoclasts to
breakdown bone release calcium and phosphorus (phosphorus is excreted from the kidneys)
- Increasing calcium absorption in
the GI tract
loss of blood calcium levels
hyperparathyroidism and hypoparathyroidism
Hyperparathyroidism
-Too much parathyroid hormone
-Over breakdown of bone
-Bone becomes weak
Hypoparathyroidism
-To little parathyroid hormone
-Insufficient extracellular calcium
-depolarization in the absence of stimuli
-Leads to tetany (twitches, spasms, convulsions)
