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• Nervous system


  Connects all body parts and transmits signals from one part to another
• Nervous system


  • System of cells, tissues, and organs that regulates the body's responses to internal and external stimuli
  • Each part has a specific role as an important part of the system
• Major divisions of the nervous system

  • Central Nervous System (CNS)
  • Peripheral Nervous System (PNS)
• Central Nervous System (CNS)


  Main processing center for the entire nervous system
• Components of the brain

  • Cerebrum
  • Cerebellum
  • Brain Stem
• Spinal cord


  Serves as a channel for signals between the brain and the rest of the body, and controls simple musculoskeletal reflexes without input from the brain
• Divisions of the Peripheral Nervous System (PNS)

  • Somatic Nervous System
  • Autonomic Nervous System
• Somatic Nervous System


  Associated with the voluntary control of body movements
• Parts of the Somatic Nervous System

  • Spinal Nerves
  • Cranial Nerves
• Autonomic Nervous System


  Associated with the involuntary control of body movements
• Subdivisions of the Autonomic Nervous System

  • Sympathetic
  • Parasympathetic
• Neuron


  The basic unit of the nervous system
• Parts of a neuron

  • Cell body
  • Dendrites
  • Axons
• Dendrites


  Carry impulses towards the cell body
• Axons


  Carry impulses away from the cell body
• Nerve impulse


  A combination of an electrical charge and a chemical reaction, not a flow of electricity
• Transmission of a nerve impulse

  1. Impulse reaches end of axon

  2. Neurotransmitter released

  3. Crosses synapse

  4. Stimulates impulse in next dendrite
• Stimulus


  Any factor in the environment that may trigger a nerve impulse
• Response


  A reaction to a stimulus
• Messages do not travel in both directions along the same neuron
• Reaction time


  Length of time between application of a stimulus and detection of a response
• The brain works round the clock for as long as you live, controlling thoughts, emotions, movements, and numerous involuntary functions
• Neurons


  Specially intended for information processing and signaling, relaying and receiving messages (impulses) between the brain and body, and within the brain and spinal cord
• Motor neurons


  Transmit impulses from the brain to muscles, glands, or other neurons in the Peripheral Nervous System (PNS)
• Sensory neurons


  Transmit impulses from sensory nerves (receptor cells) to the Central Nervous System (CNS)
• Endocrine system


  Composed of glands that secrete hormones affecting almost every cell, organ, and function of the body
• Hormones


  Chemicals secreted by endocrine glands and carried in the bloodstream to target organs
• Major endocrine glands and their hormones

  • Pituitary
  • Thyroid
  • Parathyroid
  • Thymus
  • Adrenal
  • Pancreas
  • Reproductive (testes and ovaries)
• Effects of hormones


  Regulate and balance the working of organs, tissues, and cells, influencing processes like heart rate, bone/tissue development, and reproduction
• Hormonal imbalance


  Increase or decrease in hormone amounts can have significant effects on the human body
• Reproductive system


  System involved in sexual reproduction, with striking differences between male and female systems
• Functions of the female reproductive system

  • Produces female sex cells
  • Receives sperm cell from the male
  • Nurtures development and provides nourishment for the new individual
• Reproductive system


  The system involved in sexual reproduction
• Male and female reproductive systems

  • Striking difference between them
  • They also share a number of similarities
  • Reproductive organs of the male and female are developed from the same embryological structures
  • Some hormones are commonly found in both male and female, in varying quantities and produce different responses
• Male reproductive system


  Certain parts are also part of the excretory system
• Functions of the female reproductive system

  • Produces female sex cells
  • Receives sperm cell from the male
  • Nurtures the development of and provides nourishment for the new individual
• Ovary


  Produces egg cells
• Oviduct (Fallopian tube)


  Serves as passageway of eggs from the ovary to the uterus; site of egg fertilization
• Uterus


  Serves as site of egg implantation; is where the fertilized egg develops
• Vagina


  Receives the penis of male during mating