Coordinating Responses Flashcards
What is adenyl cyclase?
An intracellular enzyme which is activated by certain hormones.
What is cAMP?
A secondary messenger released inside cells to activate a response.
The brain coordinates responses through output to the effectors. What may this outputs include?
Action potentials in the somatic nervous system
Action potentials in the sympathetic and parasympathetic parts of the autonomic nervous system
Release of hormones via the hypothalamus and pituitary gland.
What is the survival value of pupil dilation?
it allows more light to enter the eyes, making the retina more sensitive.
What is the survival value of an increase in blood pressure and heart rate?
It increases the arte of blood flow to deliver more oxygen and glucose to the muscles and to remove CO2 and other toxins.
What is the survival value of the constriction on the arterioles to the digestive system and skin, and dilation of arterioles to the muscles and liver?
Diverts blood flow away from the skin and digestive system and towards the muscles.
What is the survival value of an increase in blood glucose levels?
Supplies energy for muscular contraction.
What is the survival value of an increase in metabolic rate?
Converts glucose to useable forms of energy such as ATP.
What is the survival value of erector pili muscles in the skin contracting?
It makes the hairs stand up - which is a sign of aggression.
What is the survival value of ventilation depth increasing?
Increases gaseous exchange so that more oxygen enters the blood and supplies aerobic respiration.
What is the survival value of endorphins being released by the brain?
Wounds inflicted on the mammal do not prevent activity.
What are the receptors that can detect an external threat?
The eyes, ears and nose.
What are the four stages to the cerebrums appropriate response to a threat?
- Inputs feed into the sensory centres in the cerebrum
- The cerebrum passes signals to the associated centres.
- If a threat is recognised, the cerebrum stimulates the hypothalamus.
- The hypothalamus increases activity in the sympathetic nervous system and stimulates release of hormones from the anterior pituitary gland.
What does the sympathetic nervous system activate?
What is the net effect?
Activates adrenal medulla and secretion of adrenaline which goes into the blood stream.
Impulses activates glands and smooth muscles.
Net effect is the neural activity combines with hormones in the bloodstream to constitute fight or flight response.
What hormones are released form the pituitary gland in response to the increased activity of the hypothalamus?
CRH and TSH
