Biology key revision

• What does the hypothalamus do?

  Overall control of the endocrine system and links to the nervous system
• What does the thalamus do

  Relays sensory impulses from receptors in various parts of the body to the cerebral cortex
• How is the pinna structured

  Main part of the outer ear

  Cartilage covered with a thin layer of skin

  Specially shaped to capture sound waves
• What are the functions of the pinna


  Collects sound waves and channels them to the ear cannal
• Evolution of the horses smell

  Horses have evolved as prey species. Horses sense of smell is highly specialised and is very sensitive to impact chances of survival. Horses use there smell to select forage for Grazing. They are selective of there food and avoid poisonous plants, only selecting clean water and healthy food will improve chances of survival. Horses have large nostrils this increases surface area, allowing identification of odour particles. This allows for better sense of smell. Horses also have a flemen response this helps to trap smells
• How do the nervous systems coordinate the horses body

  Afferent (sensory nerves) respond to a stimuli (internal & external) and transmit electronic messages to the CNS in the brain The brain interprets the message and instructs the efferent (the motor neurons to co-ordinate the body's response and sends the messages to the body via the PNS to create a reaction in the target organ The PNS is responsible for relaying that information to the relevant body part
• Components of the nervous systems

  Brain: Cerebrum Cerebellum Spinal cord Spinal cord: Cord Nerves Pia matter Arachnid matter Dura mater