Flashcards in Homeostasis Deck (29):
What are the lobes of the brain?
What is the Central Nervous System comprised of?
Brain and Spinal cord
What is the Peripheral Nervous System comprised of?
Nerve and nerve cells outside the brain and spinal cord
What is the neuron responsible for?
Initiating, mediating, modulating most physiological processes in the body
What are electrical signals carried in?
What is homeostasis?
Condition of equilibrium (balance) in the body's internal environment due to constant interaction of the body's many regulatory processes
What are the normal levels within the body for PO2, PCO2, temperature, blood pressure etc?
Blood pressure- 120/80 mmHg
Plasma glucose- 5.5mM
Where is intracellular fluid?
Where is extracellular fluid?
Where is ECF in intersitial fluid?
Extracellular fluid between cells of tissues
Where is ECF in blood plasma?
Within blood vessels
Where is ECF in lymph?
Where is ECF in cerebrospinal fluid?
Around brain and spinal cord
Where is ECF in synovial fluid?
Where is ECF in aqueous humour and vitreous body?
What causes disruption in the internal body?
External environment e.g. heat, O2 levels
Internal environment e.g. reduced glucose
What 2 regulating systems bring internal environment back to equilibrium?
Endorcine and Nervous system
What is a stimulus?
A disruption that changes a controlled conditions
What is a controlled condition?
A monitored variable, e.g. blood pressure, temperatures, blood glucose levels
What is a receptor?
Monitors changes in controlled condition and sends input to a control centre
What type of pathway goes from the receptor to the brain?
What is the control centre?
Evaluates input from receptors then generates output commands when needed
What kind of signals are sent out from the Control centre?
Typically nerve impulses, hormones or other chemical signals
What type of pathway goes from the Brain to the effectors?
What is an effector?
A structure that produces a response or effect that changes the controlled condition. Most organs and tissues in the body can be an effector
What is a response?
Alters the controlled condition in some way, either reversing (negative feedback loop) or enhancing (positive feedback loop)
When is homeostasis reached?
When controlled condition is back to normal
What is a positive feedback loop?
Continually reinforces a change in a controlled condition, some event outside the system must shut it off