Session 11: Endocrine System Flashcards
How do body systems communicate with each other?
Nervous system
Endocrine system
What is the nervous system made up of?
Central Nervous System (Spinal cord and brain)
Peripheral Nervous System (Cranial and spinal)
What is the difference between somatic and autonomic nervous systems?
Somatic nervous system is responsible for motor and sensation
Autonomic nervous system is responsible for the “background” operations and is self-regulating
The autonomic nervous system can be further divided into what?
Sympathetic and Parasympathetic
What are the differences between sympathetic and parasympathetic nervous systems?
Sympathetic nervous system prepares for fight or flight (Stimulatory)
Parasympathetic nervous system prepares for rest or digest (Inhibitory)
Sympathetic nerve vessels innervate all vessels except what?
Capillaries and precapillary sphincters which follow local control
The sympathetic division of the nervous system prioritises blood vessels to what areas of the body in times of emergency?
Brain
Skeletal muscles
Heart
During times of emergency, the sympathetic division of the nervous system minimise blood from to where? How?
Skin and other organs (besides brain, skeletal muscle and heart)
Vasoconstrict these vessels to minimise bleeding if inury occurs
How does sympathetic tone relate to the action of the blood vessels?
The Sympathetic NS and the Parasympathetic NS usually work in balance, but in the blood vessels it is mainly sympathetic
The stronger the sympathetic tone the more smooth muscle contracts and the vessels vasoconstrict
The weaker the sympathetic tone, the more the smooth muscles relax and the vessels vasodilate
Venoconstriction _________ cardiac return
Increases
Give three examples of areas of the body that use neurocrine communication
Anterior pituitary
Posterior pituitary
Adrenal medulla
What are the main endocrine glands/organs?
Pineal gland Hypothalamus Pituitary gland Thyroid gland Parathyroid gland Thymus Adrenal glands Pancreas Gonads
Where is the thymus located?
In the superior mediastinum
Hormones control and regulate what?
Reproduction Metabolism and energy balance Growth and development Body defences General homeostasis and water, nutrient and electrolyte balance
At what point do the CNS and the endocrine system communicate?
Hypothalamus
The hypothalamus is central to what?
Homeostasis
What is another name for the pituitary gland?
Hypophysis
The pituitary is divided into how many lobes?
What are they called?
Two
Anterior pituitary
Posterior pituitary
The hypothalamic-pituitary-thyroid axis controls what?
Metabolic rate
The hypothalamus releases what hormone?
Thyrotropin releasing hormone (TRH)
What does TRH do?
Stimulates the release of thyroid stimulating hormone (TSH)
What does TSH do?
Stimulates the release of T3 and T4 from the thyroid gland
Where are the adrenal glands located?
On top of each kidney
Adrenal glands are made up of an outer _______ __________ and an inner ________ ________
Adrenal medulla
Adrenal cortex
What cells that secrete catecholamines can be found in the adrenal medulla?
Chromaffin cells
What are catecholamines?
Adrenaline and noradrenaline
What are the short -term stress responses of catecholamines?
Increased heart rate Increased BP Liver converts glycogen to glucose and releases it into the blood Bronchioles dilate Increased metabolic rate
What are the long-term responses of catecholamines?
Retention of sodium and water by the kidneys
Increased blood volume and blood pressure
Proteins and fates are converted into glucose or broken down for energy
Increased blood sugar
Suppression of the immune system
What are the posterior pituitary hormones?
Where are they produced?
ADH and oxytocin
Hypothalamus
How do ADH and oxytocin get to the posterior pituitary from the hypothalamus?
Travel down the neuronal axons and are secreted adjacent to the capillaries of the posterior pituitary
What does the pineal gland produce?
Melatonin
What is melatonin involved in?
The control of circadian rhythmn
What does melatonin inhibit the release of?
Gonadotrophins (LH and FSH)
What happens to the pineal gland in early adulthood?
It calcifies and is therefore visible on x-rays
