Endocrine System Flashcards
Describe Exocrine Glands?
Exocrine glands secret into ducts and so act locally. Sweat glands.
Describe Endocrine Glands?
No ducts. Secrete hormones into blood stream and so act at a distance.
What are some examples of endocrine glands and their associated hormones?
Metabolic rate - (Thyroid) Reproduction - Oestrogen/ testosterone) Stress Response - (Adrenaline&cortisol) Blood Glucose - (insulin glucagon) Blood Pressure - ADH, Aldosterone Immune system - Cortisol Growth (Growth Hormone) Blood Calcium (calcitonin/parathyroid)
Does the nervous system and the Endocrine system work closely together?
Yes. The nervous system works by releasing neurotransmitters into synaptic clefts and the Endocrine system works by releasing hormones into the blood stream.
What are some of the characteristics of NS and ES?
NS - Fast and short lasting and uses neurotransmitters at synapses
ES - Slow and long lasting and uses hormones produced in bloodstream.
Hormones only affect certain cells, how so?
Hormones only stimulate cells that have a matching receptor
What are the two hormone groups?
Water Soluble hormones (proteins) and Lipid Soluable hormones (steroids)
How do water soluble hormones work?
Mostly proteins.They require a second messenger receptor on the cell membrane?
Hypothalamic and pituitary hormones, GIT and insulin/adrenaline.
How do lipid soluble hormones work?
Mostly steroids. such as Sex hormones, cortisol, aldosterone, thyroid.
Lipid soluble hormones diffuse across the lipid portion and bind to receptors inside the cell
Describe the hypothalamus and pituitary gland and their connections?
The hypothalamus is the master gland and controls the pituitary. The pituitary is divided into two parts, the posterior pituitary (30%) and the anterior pituitary (70%). The PP is connected to the hypothalamus by neurons and is composed of nervous tissue while the AP is connected to the hypothalamus by blood vessels and is composed of glandular tissue.
What hormones do the PP and AP store and release?
The PP stores Oxytocin and ADH hormone and the AP stores six main hormones.
What does Oxytocin hormone do when released from PP?
Oxytocin release is triggered by a baby suckling on mothers breast and its release from PP activates milk ejection.
What do ADH hormone do when released from PP?
ADH acts on kidney to increase reabsorption in blood in order to decrease urine output
Decreases sweat production
What triggers stimulate the release of ADH?
Dehydration or severe blood loss.
What does the release of ADH stimulate?
- Increase reabsorption of water by kidneys
- Reduced sweat output
- Arteriole constriction to increase bp
- decrease urine output