Communication, Control, Protection Flashcards
Neurone
Remember there are motor and sensory
Cell body, axon, myelin sheath, nerve terminal and synapse
Nervous system
Conscious control Unconscious control
Somatic Autonomic
Sympathetic Parasympathetic
Fight Flight Rest Restore
The endocrine system
The brain controls it, having the master gland the pituitary.
Thyroid
Parathyroid
Pancreas (insulin and glucagon)
Adrenal glands (cortisol, adrenaline, aldosterone and ADH)
Reproductive glands (testosterone, oestrogen and progesterone)
(Growth hormone, oxytocin)
What does endocrine mean?
Ductless gland
Secrete their hormone into the blood stream
Glands with ducts are called exocrine glands
Relationship between nervous and endocrine systems
They can work together to induce and maintain a response. The nervous system is fast and can produce an almost immediate response but has trouble sustaining it. The endocrine system can cause changes to the body that allow for the long term maintenance of that response.
What are hormones made out of?
Usually amino acid based
Could be protein, peptide, amine or steroid
Thyroid hormone
Controls BMR (metabolism)
Higher = faster and hotter
Increases if cold
Essential for normal development of tissues
Thyroid problems
Too much: -weight loss, tissues get fatigued -anxious, feeling on edge, higher heart rate -oversensitive to heat -diarrhoea Too little: -weight gain -oversensitive to cold -lethargic -dry skin and puffy face -constipated
Insulin
Released by the pancreas in response to high blood glucose levels
Insulin encourages the uptake of glucose into the cells
Lack of insulin means two bad things
1. Too much blood glucose> bad
2. Cells not getting glucose> bad
Glucagon
Released by the pancreas when blood sugar levels are low
Mobilises stored glycogen to increase BGL
Normal BGL when fasting = 4-6mmol
Parathyroid
Located on the back of the thyroid gland
Detects when plasma calcium levels are low and secretes hormone
1. Calcium striped from bones
2. Kidneys reduce excretion calcium
3. Increased production of vitamin D
Parathyroid problems
Too much: -Weak, holly bones -calcium deposits in lungs -kidney stones Too little: -effects on nervous and muscle control - CATS (convulsions, arrhythmias, tetany, stridor and spasms)
Cortisol
Secreted by the adrenal cortex Is the hormone for long term stress response (fight/flight) Increases blood glucose Increases blood lipids Inhibits growth and repair Inhibits immune response
Cortisol problems
Too much: -high BP -enlarged heart -moon face -prone to infection -slow repair -diabetes like high BGL Too little: -weak and cant mount good stress response -weight loss -low blood glucose and associated effects
Aldosterone
Increases retention of sodium and thus water by the kidney
Aldosterone problems
Too much: -sodium and water retention ->increase blood pressure and volume ->swelling Too little: -not enough sodium or water (Aldosterone problems rarely occur alone. They are usually as a result of some other failure first)
Adrenaline
Comes from adrenal medulla
Prolongs the fight or flight response of the sympathetic system
Sex hormones: female
Oestrogen:
Maintains many tissues, regulates menstrual cycle, determines secondary sex characteristics, metabolic effects
Progesterone:
Release of egg from ova, implantation and maintenance of pregnancy,
Sex hormones: male
Also known as androgens, testosterone is the main one
-development and maintenance of male sex hormones, secondary sex characteristics, production of sperm
Oxytocin
Produced in child birth> powerful uterine contractions
Allows milk letdown (not production)
The love hormone, important in bonding and reducing anxiety
ADH
Released by axons that connect the hypothalamus to the pituitary
Triggered by decreased blood volume or osmolarity
Causes the retention of water and causes thirst
ADH problems
Too much: -concentrated urine -high blood volume and pressure Too little: - dehydrated -hypotension and associated issues
How do the two systems interact?
“Hypothalmopituitary access”
The hypothalamus and pituitary gland meet. The hypothalamus detects nervous signals and communicates these to the pituitary which then causes a hormonal response
Usual order of communication
Hypothalamus (hypothalamic hormone) RH Releasing Hormone
Pituitary (pituitary hormone) SH stimulating hormone
