Homeostasis And The Endocrine System Flashcards
What is homeostasis?
The existence of a stable environment
Name some conditions that must be controlled by the body
Body temperature
Water content
Carbon dioxide
Blood sugar
Blood pressure
What is homeostatic regulation?
The adjustment of physiological systems to preserve homeostasis
Name the 5 elements of a homeostatic control system
Stimulus
Receptor
Input
Output
Response
Which type of feedback is more common negative or positive?
Negative feedback
Name some negative feedback systems
Temperature control
PH
Blood sugar
Name some positive feedback systems
Haemostasis
Labour and delivery
What is the control centre for thermoregulation?
Hypothalamus
Name some heating mechanisms of the body
Shivering
Hairs on our body stand up
Response to get up and move
Name some cooling mechanisms in the body
Sweating
Redistribute the blood
What are the two main systems for homeostatic regulation?
Intrinsic and extrinsic
What is another name for intrinsic regulation?
Auto regulation
What is auto regulation?
It is when cells, tissues and organs adjust automatically to environmental changes
What is extrinsic regulation?
It results in either your nervous system making changes or your endocrine system
What can cause homeostasis to go wrong?
An infection, injury or a genetic abnormality
Who are most vulnerable to homeostatic disruption?
Newborns and elderly
Why are newborns vulnerable to homeostatic disruption?
Because of the immaturity of their systems such as immune system, renal function, endocrine system, thermoregulation
Why are elderly more vulnerable to homeostatic disruptions?
They are less responsive to hormones
Have decreased efficiency of the heart and circulatory system
Have loss of neurones and neurotransmitters (nervous system is slower)
What are the two types of glands?
Exocrine and endocrine
What do exocrine glands do?
They secret their products into ducts that empty out into a surface or cavity
What do endocrine glands do?
They secret hormones into intracellular spaces, then hormones diffuse into the bloodstream,
Do endocrine glands have ducts?
No
Name 3 systems that produce hormones that aren’t glands
Stomach
Small intestines
Kidney
What are the main functions of the endocrine system
They regulate sodium and water balance (blood volume)
They regulate calcium and phosphate balance (preserves extra cellular fluid concentration for cell survival )
They regulate energy balance and control of macronutrient utilisation and storage
Regulate responses to stress
Regulate reproduction, sexual development and growth
What are the 2 types of hormones?
Non-steroidal hormones
Steroidal hormones
Which category of hormone attaches to a surface receptor?
Non-steroidal hormone
What mechanism do non-steroidal hormones work by?
Second-messenger mechanism
What are non-steroidal hormones?
Whole proteins which are short chains of amino acids or could just be one amino acid
Which category of hormone can pass through the cell membrane of the target organ?
Steroidal hormones
What are steroidal hormones?
Small lipid soluble chemical
Which category of hormone normally has a slower action?
Steroidal hormones
Which category of hormone will produce a hormone-receptor complex?
Steroidal hormone
What are the two types of non-steroidal hormone?
Protein or peptide hormones
Amino acid derived hormones
Which type of non-steroidal hormone is more common?
Protein or peptide hormones
How are protein/peptide hormones synthesised?
They are synthesises as pre-prohormones in which they undergo transformation at the required time
Where are protein/peptide hormones stored?
They are stored in secretory glands
Give some examples of protein/peptide hormones
Insulin
Glucagon
Adrenocorticotropic hormone (ACTH)
What are amino-acid derived hormones synthesised from?
Other amino acids
Give some examples of amino-acid derived hormones
Adrenaline
Noradrenaline
Dopamine