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  • Homeostasis
    • Maintaining a constant internal environment
    • Maintaining a body equilibrium
  • Body ‘systems’ are used to intellectually organise information


  • Musculoskeletal
    • Muscles embedded in a lacy network of collagen
  • Nervous system
    • Central Nervous System (CNS)
      • Brain
        • Cerebrum and Cerebellum
      • Spinal chord
    • Peripheral Nervous System (PNS)
      • Neurones and everything else


  • Made up of the cerebrum and cerebellum
  • Contains many gyri (ridges) and sulci (crevices)
  • Insula
    • Covered by other parts as it is anchored
    • First to mature
  • White matter – myelinated nerve fibres
  • Grey matter – rich blood supply containing more nerves
  • Cerebral cortex is anchored chemically, mechanically, electrically etc by parietal tracks

Spinal Cord

  • Grows at a different rate to the vertebral column
    • In adults it extends down to L1
    • In children it extends lower
    • In the embryo it extends all the way to the coccyx
  • Divided into segments
    • Holes between vertebra through which the nerves fit define the levels
    • Segments in the skin correspond to segments in the spinal cord – known as dermatomes

Peripheral Nervous System

  • Has a plexus (braid) formation
    • Braids follow the limbs: upper arm, neck, lumbar/sacral area
    • Forms braids due to human geometry
  • Diagram - embryo
  • Divided into autonomic and somatic
    • Autonomic = smooth muscle/non voluntary movements, efferent
      • Sympathetic – thoracic and lumbar sections of spinal cord
      • Parasympathetic – cranial and sacral sections of spinal cord
    • Somatic = voluntary, sensing and controlling: efferent and afferent
    • Diagram – PNS outside, CNS inside diagram

Endocrine system

  • Head station = pituitary gland/hypophysis
    • Uses hormones (chemical messengers) to stimulate glands
    • Anything that releases chemicals to affect another organ is an endocrine organ
  • Thyroid/parathyroid
  • Adrenal (suprarenal) – located above the kidneys
    • Has a centre medulla that liquefies at death and thus the cavity collapses
    • May have smaller ones located not just above the kidneys

Thoracic Viscera

Circulatory system

  • Heart:
    • Located in the pericardial sac containing pericardial fluid
      • Lubricates the heart cavity
    • Stabilised by tubes that come and go from all directions
    • Cardia muscle is formed in spirals and is anchored to the cardiac skeleton
    • In humans, the heart cavity is made of collagen
    • In animals, made of bone: os cordis
    • Macrocirculation – arteries and veins (things you can see)
    • Microcirculation – <0.1mm
    • Arteries are accompanied by veins: venae comitantes
    • When veins meet arteries we get a capillary
    • Artery becomes an arteriole then a capillary then a venule

Gastrointestinal tract

  • stomach, gall bladder, liver, intestines etc

Urinary Tract

  • Controls the ionic concentration of body fluids
  • Controls pH
  • Controls fluid levels
  • Controls blood pressure
  • Controls red blood cell production
  • Metabolises vitamin D
  • Excretes waste

Reproductive system