bio nervous and endocrine

• Main communication systems in the body

  • Nervous control
  • Chemical control
• Nervous control


  Depends on electrical impulses travelling via neurons for quick, targeted responses
• Chemical control


  Uses hormones released into the circulation for slower, more broad effects
• Parts of the nervous system

  • Nervous system
  • Endocrine system
• Nervous system


  Responsible for coordinating the functions of the other body systems. It gathers information, processes the information and elicits a corresponding response or reaction to the stimuli
• Endocrine system


  Consists of the tissues (mainly glands) that create and release hormones. Responsible for releasing hormones into blood while continuously monitoring the levels
• Hormones


  Chemical messengers created by the body. They transfer information from one set of cells to another to coordinate the functions of different parts of the body
• Divisions of the nervous system

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


  Composed of the brain and spinal cord
• Brain


  The control center; It receives and processes, sensory, information, initiates, responses, stores memories, generates thoughts and emotion
• Spinal cord


  Connects the brain to other nerves of the body; it conducts signals to and from the brain, controls reflex activities
• Peripheral Nervous System (PNS)


  Involves the parts of the nervous system outside the brain and the spinal cord
• Parts of the PNS

  • Motor neurons
  • Sensory neurons
• Motor neurons


  Responsible for carrying information from the brain and spinal cord to muscle fibers throughout the body
• Parts of the motor nervous system

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


  Controls voluntary movements
• Autonomic Nervous System


  Controls involuntary movements
• Parts of the autonomic nervous system

  • Sympathetic
  • Parasympathetic
• Sympathetic


  Best known for its role in responding to dangerous or stressful situations. It is dubbed as the "fight or flight" in the nervous system
• Parasympathetic


  Carries signals to relax the sympathetic responses (flight or fight) and predominates in quiet "rest and digest" conditions
• Sensory neurons


  Responsible for carrying information from the body to the CNS
• Neuron


  Transmits electrical signal called action potential or impulse across the system and lets a body part respond accordingly
• Impulse


  Sudden change in the electrical potential of the cell membrane
• Basic parts of a neuron

  • Dendrites
  • Soma
  • Axon
• Dendrites


  Several projections which extends outwards from the cell body to receive chemical signals from the axon terminals of another neuron
• Soma


  The cell body, contains the nucleus and most organelles
• Axon


  Single projections from the some which carries the impulses to the axon terminal. Some are enveloped by myelin sheath for faster conduction of impulse
• Myelin sheath


  Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulation layer. It is essential for the proper functioning of the nervous system
• Feedback mechanism


  Mechanism or a signal that tends to initiate (or accelerate) or to inhibit (or slow down) a process
• Endocrine glands

  • Hypothalamus
  • Anterior pituitary gland
  • Parathyroid Gland
  • Thyroid Gland
  • Adrenal Gland
  • Pancreas
  • Kidneys
  • Ovaries
  • Testes
• Hypothalamus


  Section of the brain responsible for the production of many of the essential hormones in the body that govern physiologic functions such as temperature regulation, thirst, hunger, sleep, mood, sex drive, and the release of hormones within the body
• Anterior pituitary gland


  Also known as adenohypophysis, is one of the two lobes of the pituitary gland controlled by the hypothalamus. The anterior pituitary secretes a number of peptide and glycoprotein hormones that regulate various cellular processes including growth, metabolism, reproduction, and response to stress or trauma
• Parathyroid Gland


  Small endocrine glands situated just below the thyroid glands in the neck. The glands function to maintain the calcium and phosphorus levels in our bodies
• Thyroid Gland


  Butterfly-shaped gland that sits in the front of the neck
• Adrenal Gland


  Found on top of each kidney. One of the most well-known responses – the Fight or Flight Response is triggered by the release of stress hormones from the adrenal glands
• Pancreas


  A long, slender organ, most of which is located posterior to the bottom half of the stomach. Although it is primarily an exocrine gland, secreting a variety of digestive enzymes, the pancreas has an endocrine function. Islets of Langerhans secrete the hormones glucagon, insulin, somatostatin, and pancreatic polypeptide (PP)
• Kidneys


  Small bean-shaped organs approximately 6 cm wide and 12 cm long and consist of two main layers – an inner layer called the medulla and an outer layer called the cortex. One of its functions is to ensure that the make-up and volume of the fluids in the body is correct
• Ovaries


  Almond-shaped glands in which oocytes develop and produce the female hormones estrogen and progesterone
• Testes


  Paired ovoid glands that produce spermatozoa and the male hormone testosterone
• Sensory receptors


  Specialized, excitable cells that are designed to convert a physical stimulus in the external world or one that occurs inside our bodies into electrochemical signals of the nervous system