Biology

• What is the Peripheral Nervous System composed of?

  It is composed of neurones that conduct electrical impulses through the body.
• What is a nerve?


  A nerve is a bundle of many neurones enclosed in a protective sheath.
• What is the function of sensory neurones?

  Sensory neurones transmit messages from sense receptors to the Central Nervous System (CNS).
• What do motor neurones do?

  Motor neurones transmit messages from the CNS to the muscles and glands as a response to a stimulus.
• What is myelin sheath?

  Myelin sheath is the fat or lipid around the cells that stops wrong transmissions.
• What is the order of operations in a reflex action?

  The order is stimulus, receptor, coordination, response, effector.
• What are the components of the Central Nervous System?

  The Central Nervous System consists of the brain and spinal cord.
• What is the role of the cerebellum?

  The cerebellum fine-tunes muscle actions and has a role in balance and coordination.
• How can reaction times be measured in a practical test?

  By using the stick drop test where a partner drops a ruler and the participant catches it as quickly as possible.
• What does the stick drop test measure?

  It measures the reaction times of individuals in a group.
• What is a reflex action?

  A reflex action is a non-conscious survival action triggered by the spinal cord.
• What is the function of synapses?

  Synapses convert electrical impulses to chemical impulses across a gap between neurones.
• What is the role of neurotransmitters?

  Neurotransmitters diffuse across the synaptic cleft and bind with receptors on the next neurone, triggering another impulse.
• What happens to the pupil in bright light?

  A reflex is triggered that makes the pupil smaller by contracting the circular muscles and relaxing the radial muscles.
• How does the body respond to dim light?

  The radial muscles contract and the circular muscles relax, making the pupil wider.
• What is homeostasis?


  Homeostasis is the process of keeping internal conditions within tolerances.
• What factors are kept constant in homeostasis?

  The factors include temperature, water, and glucose levels.
• How do ectotherms regulate their body temperature?

  Ectotherms rely on their surroundings to regulate their body temperature.
• What is the role of the endocrine system?

  The endocrine system relies on hormones to spread more slowly and act more generally in the entire body.
• What does the pituitary gland do?

  The pituitary gland produces many hormones that regulate body conditions and is sometimes called the 'master gland'.
• What hormone does the adrenal gland produce?

  The adrenal gland produces adrenaline, which prepares the body for the fight or flight response.
• What hormone does the thyroid produce?

  The thyroid produces thyroxine, which regulates metabolism, heart rate, and temperature.
• What is the function of insulin?


  Insulin is used to regulate blood glucose levels.
• What hormone do ovaries produce?


  Ovaries produce oestrogen, which is involved in the menstrual cycle.
• What hormone do testes produce?


  Testes produce testosterone, which controls puberty and sperm production in males.
• What is the role of the hypothalamus?

  The hypothalamus links the nervous system and the endocrine system.
• How do hormones affect the body?

  Hormones act on other glands to direct changes in the body.
• How do the nervous system and endocrine system differ in their communication methods?

  The nervous system uses electrical impulses for fast communication, while the endocrine system uses hormones that spread more slowly.
• What are the key differences between the nervous system and the endocrine system?

  • Nervous System:
  • Uses electrical impulses
  • Very fast communication
  • Targets specific areas

  
  

  • Endocrine System:
  • Relies on hormones
  • Spreads more slowly
  • Acts more generally in the entire body
• What are the main functions of different parts of the brain?

  • Cortex: Creativity and advanced human capabilities
  • Cerebellum: Fine-tunes muscle actions, balance, and coordination
  • Medulla: Triggers reflex actions and controls involuntary functions like breathing
• What are the components of a reflex arc?

  1. Stimulus
  2. Receptor
  3. Sensory neurone
  4. Relay neurone
  5. Motor neurone
  6. Effector (muscle or gland)