Module 5 Communication, homeostasis & energy Block 2C – 5.5 Animal responses 5.5.7 Coordinated responses

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Learning Objectives Success Criteria To understand how muscles, nerves and hormones work together State that responses to environmental stimuli in mammals are coordinated by the nervous and endocrine systems (Grade E - D) Identify physiological changes in flight or fight response (Grade C –B) Explain how the fight or flight response is coordinated by nerves and hormones (Grade B – A) 3

Complete exam question

Pulling Together Responses to environmental stimuli in mammals are coordinated by the nervous and endocrine systems Stimuli from external environment feed information into systems Brain assesses appropriate response Ensure survival Short term e.g. homeostasis Long term e.g. reproductive behaviours

Flight or Fight Response Coordinated by nervous and endocrine systems Threat to safety of organism leads to variety of physiological changes Either escape or challenge threat Heightened awareness to assess threat

Mind map all the physiological changes these people are experiencing with the fight or flight response

Flight or Fight Response: Physiological Changes Heart rate increases Arterioles to muscles dilate Blood glucose levels increase Metabolic rate increases Ventilation rate increases Endorphins (natural pain killers) released How does each of these changes help the person prepare for action

Survival value Annotate each physiological response to explain how it helps the person survive.

Flight of Fight Response Cerebral understanding of threat received from receptors Signals passed to association centres and hypothalamus is activated Stimulates sympathetic nervous system Stimulates the release of hormones from the anterior pituitary gland Receptors such as eyes, ears nose – detect an external threat. Internal receptors detect pain, or increase/decrease in BP.

The action of the hypothalamus Complete the flow diagram on page 99 to explain the action of the hypothalamus, add to your diagram information on tropic hormones page 100 Increasing sympathetic – increases activity of the effectors – RAPID RESPONSE BY NERVES. PROLONGED RESPONSE = ENDOCRINE SYSTEM

Adrenaline – Cell signalling Adrenaline (first messenger) binds to adrenaline receptor. This receptor is associated with A g protein, which is stimulated to activate enzyme adenyl cyclase Adenyl cyclase converts ATP to cyclic AMP (cAMP) this is the second messenger cAMP causes an effect inside the cell Adrenaline does not cross the membrane (amino acid derivative) Protein kinase A can have different effects depending on the cell the adrenaline has bound to. It can also affect Ca channels which in turn affect muscle contraction

Hormones Hypothalamus releases hormones into the blood, these pass down the portal vessel to the pituitary gland and stimulate the release of tropic hormones, which then stimulate the endocrine glands

Exam questions How does the secretion of adrenaline prepare the body for muscular activity? (4 marks) Adrenaline and cyclic AMP are both messengers molecules. Explain how they perform different but related functions. (2 marks) Explain how the release of adrenaline from the adrenal gland can bring about responses in a range of tissue types. (2 marks)

Plenary - SA Adrenaline increases the level of glucose in the blood (1) increases ventilation rate (1) increases heart rate (1) cause the arteriole to the muscle to dilate (1) Adrenaline binds to the receptor on the surface of a cell causing a response inside the cell (1) cAMP acts on enzymes inside the cell bringing about a response (1) Adrenaline travels through the blood (1) Blood reaches all cells in the body, and adrenaline binds with receptors on the surface of different tissue types(1)

Learning Objectives Success Criteria To understand how muscles, nerves and hormones work together State that responses to environmental stimuli in mammals are coordinated by the nervous and endocrine systems (Grade E - D) Identify physiological changes in flight or fight response (Grade C –B) Explain how the fight or flight response is coordinated by nerves and hormones (Grade B – A) 17