Lifesciences

• PUPIL

  Controls the amount of light that enters the eye by contracting and expanding
• SCLERA


  Outer coat that protects the eye from damage
• CILIARY MUSCLE

  Helps keep the shape of the eyeball by supporting the lens and keeping the retina in place
• BLIND SPOT


  Exit point of the optic nerve
• OPTIC NERVE


  Composed of sensory neurones that carry nerve impulses to the visual centre
• CORNEA


  Transparent layer that refracts most of the light rays that enter the eye
• CHOROID


  Dark layer that reduces reflections inside the eye and contains blood vessels to help nourish the retina
• VITREOUS HUMOUR


  Jelly-like substance which helps keep the shape of the eyeball
• LENS


  Focuses light onto the retina
• RETINA

  Contains the light-sensitive cells, rods and cones
• AQUEOUS HUMOUR


  Watery fluid which supports the cornea and front chamber of the eye
• SUSPENSORY LIGAMENT


  Controls the amount of light that enters the eye by changing the size of the pupil
• YELLOW SPOT (FOVEA)


  Area has the highest density of cones and offers maximum sharpness
• Types of neurons

  • Sensory neurons: carry impulses from receptors to the central nervous system
  • Motor neurons: carry impulses from the central nervous system to effectors (muscles or glands)
  • Connector neurons/interneurons: carry impulses inside the central nervous system from a sensory neuron to a motor neuron
• Systems used by humans to respond to the environment

  • Nervous system with its sensory receptors
  • Endocrine system
• The myelin sheath provides electrical insulation and helps to speed up the transmission of nerve impulses
• Neurons

  • Neurons are composed of nerve fibres made up of specialized nerve cells called neurons
  • Neurons are lined up in such a way that the axon terminals of one neuron lie next to the dendrites of another
  • Neurons are not directly connected to each other, there is a microscopic gap or synapse between them
• The need for a nervous system

  • Detects changes in the environment allowing the body to react
  • Enables coordination of various activities of the body
• All neurons consist of a cell body with dendrites and an axon. A nerve impulse always travels from the dendrites to the cell body to the axon
• Transmission of nerve impulses

  1. Neurons carry nerve impulses along the neuron by electrical impulses

  2. Communication across the synapse is by means of chemicals called neurotransmitters
• Communication across the synapse


  Is by means of chemicals called neurotransmitters
• Endocrine glands include the pituitary gland (located at the base of the brain), thyroid gland (in the neck), parathyroid glands (also located in the neck), adrenal glands (on top of the kidneys), pancreas (behind the stomach), ovaries (female sex organs) and testes (male sex organs).
• Hormones are chemical messengers produced by various organs or tissues, which travel through the blood to target cells where they bind to specific receptors on the cell surface or inside the cell.
• Neural networks are capable of learning complex patterns and can be trained on large amounts of data to perform tasks like classification, prediction, and regression.
• They are made up of interconnected nodes that operate like neurons firing and connections that operate like synapses.
• Artificial neural networks are computational models inspired by biological neural networks in the human brain.
• The endocrine system is made up of glands that secrete hormones into the bloodstream.
• Renal failure occurs when the kidneys are no longer able to perform their functions effectively due to damage or disease.
• <S:General relativity is Einstein's theory of gravity as the geometric properties of space and time.
• Massive objects like planets and stars cause a bending of space-time, which in turn affects the motion of other objects.
• Target tissue responds to hormone binding by changing its activity level.
• Hormones are chemical messengers produced by endocrine glands which travel through the bloodstream to target tissues where they bind to specific receptors on the surface of cells.
• Examples of hormonal control include growth and development, reproduction, metabolism, water balance, salt concentration, heart rate, blood pressure, sleep/wake cycle, stress response, immune function, sexual characteristics, lactation, and mood.
• A neural network consists of interconnected nodes that process information based on input signals received from other nodes.
• A hormone can be defined as any substance that regulates the activity of another organism or part of the same organism.
• The hidden layers process this information using mathematical functions and pass it forward to the output layer.
• Each node receives inputs from multiple sources and performs some computation based on those inputs.
• The input layer receives information from external sources such as sensors or other neural networks.