Intro to Endocrine System, Control of Appetite Flashcards
Is homeostasis a steady state or a dynamic equilibrium
Describe the control system, identifying the 4 components as well as the communication pathways involved
A dynamic equilibrium
- Stimulus
- Receptor (Detects stimuli)
- Afferent pathway
- Control centre (Determines set point)
- Efferent pathway
- Effector (Causes change)
What is a biological rhythm
What regulates a circadian rhythm
A cyclic change in the level of a bodily chemical/function
Circadian rhythm regulated by neurones in Suprachiasmatic Nucleus
Identify 5 things that maintain the biological clock
Which hormone is involved in setting the biological clock and where is it released from
- Light
- Temperature
- Social interaction
- Exercise
- Eating/ drinking pattern
Melatonin from Pineal Gland
What do Proprioceptors and Nociceptors sense
Proprioceptors sense position
Nociceptors sense pain
How is high blood osmolatility returned to normal (275-295)
- Detected by osmoreceptors in hypothalamus
- Thirst-> Drinking reduces osmolatility
- Posterior pituitary secretes MORE ADH-> Increased kidney reabsorption of H2O
What is the endocrine system
Name the 10 major endocrine glands
A collection of glands located throughout the body
- Hypothalamus
- Pituitary Gland
- Thyroid Gland
- Adrenal Gland
- Pineal Gland
- Parathyroid gland
- Thymus
- Pancreas
- Testes/ ovary
Identify the mechanisms of hormone communication
What are catecholamines
Autocrine
Paracrine
Endocrine
Neurocrine (Hormone made in neuron, transports down axon and released into blood)
Hormones made in adrenal glands
What are the 4 classes of hormones
Give 3 examples of each
Peptide;
- Insulin
- Glucagon
- Growth hormone
Amino acid derivatives;
- Adrenaline and Noradrenaline
- Melatonin
- Thyroid hormones
Glycoproteins;
- FSH
- LH
- TSH
Steroids (Derived from cholesterol);
- Cortisol
- Aldoserone
- Testosterone
Describe the solubility of the 4 hormone classes
Peptides- Water soluble
Glycoproteins- Water soluble
Steroids- Lipid soluble
Amino acid derivatives- Thyroid hormones are lipid soluble, Catecholamines are water soluble
What are the methods of hormone transport
What the roles of carrier proteins
- Travel in blood in simple solution
- Must bind to proteins (Often specific)
- Increased hormone solubility in plasma
- Increased half life of hormones
- Readily accessible reserve of hormones
What factors determine hormone levels in blood
Rate of production
Rate of delivery (More blood flow to an organ delivers more hormone)
Rate of degradation
What receptors do H2O soluble and Lipid soluble hormones
Lipid soluble: Intracellular receptors
Water soluble: Cell surface receptors
Where is the appetite control centre located
What plays a central role in appetite control
In hypothalamus Arcuate Nucleus (A cluster of neurons in hypothalamus)
What neurones process neuronal, nutrient and hormonal signals
What are the 2 types and what do they promote in regards to hunger/ appetite
Primary neurones in arcuate nucleus
Stimulatory neurones: Contain NPY (neuropeptide Y) and AgRP (agouti-related peptide). PROMOTE HUNGER
Inhibitory neurones: Contain POMC, which produces transmitters like Alpha-MSH and Beta-Endorphin. PROMOTE SATIETY
How do primary neurons carry along impulses to alter feeding behaviour?
Primary neurons synapse with secondary neurones in other regions of hypothalamus and the signals integrate
