paper two

• Homeostasis


  Maintaining a Stable Internal Environment
• The body needs to keep the conditions steady for cells to function properly
• Homeostasis involves responding to changes in both internal and external conditions
• Control systems in the body

  • Include both nervous and hormonal components
• Control systems in the body

  • Maintain body temperature, blood sugar levels, and water balance
• Automatic control systems

  Receptors, coordination centers, effectors work together to maintain a stable condition
• Negative Feedback Counteracts Changes
• Negative Feedback Mechanism

  Receptor detects a stimulus, coordination center processes the information and organises a response, effector produces a response to counteract the change and restore the optimum level
• Effectors continue producing responses until the level is back to normal due to negative feedback
• Negative feedback is an automatic process that happens without conscious thought
• The Nervous System Detects and Reacts to Stimuli
• Parts of the Nervous System

  • Central Nervous System (CNS), Peripheral Nervous System (PNS), Neurones, Motor Neurones, Effectors, Receptors
• The Central Nervous System (CNS) consists of the brain and spinal cord
• Every neurone carries information as electrical impulses from receptors to the CNS
• Motor neurones carry electrical impulses from the CNS to effectors
• Effectors are muscles and glands that respond to nervous impulses
• Devery Neurones
• The arces thet carry lamation as electrical impulses fom the receptors to the CNS
• Motor Neurones
• The genes that carry electrical impulses from the CNB to effectes
• Effectors
• All your muscles and glands which respond to nervous impulses
• Receptors and Effectors can form part of Complex Organs
• Types of receptors

  • Detect stere
  • Taste receptors on the tongue
  • Sound receptors in the ears
• Receptors can form part of large complex organs such as the sting of the sui covered in light receptor cells
• Effectors respond to nervous impulses and bring about a change
• Muscles and glands are known as effectors - they respond in different ways. Muscles contract in response to a nervous impulse whereas glands secrete hormones
• The Central Nervous System (CNS) Coordinates the Response
• The CNS is a coordination centre - it receives information from the receptors and then coordinates a response (decides what to do about it). The response is carried out by effectors
• For example, a small bird is eating some seed when, out of the corner of its eye, it spots a cat skulking towards it (this is the stimulus)
• The receptors in the bird's eye are stimulated. Sensory neurones carry the information in the receptors to the CNS
• The CNS decides what to do about it. The CNS sends information to the muscles in the bird's wings (the effectors) along motor neurones. The muscles contract and the bird flies away to safety
• Synapses and Reflexes
• Naurant information to and from the brain, and your banda d how to respond to a stinks Bur fees are an quick
• Synapses Connect Neurones
• The nerve signed is transferred by shenkos which dat (nove) scross the gap
• These cherskuds n set off a pecericall
• Reflexes Help Prevent Injury
• Before are capid, automatic responies to certain oval that dater he goes part of the brain - they can reduce the chances of being injure
• For example, if some hises bright light in your eyes your call that less light gets into the age the stops in getting d