coordination

• Coordination


  Interaction function
• Coordination process


  1. Stimuli

  2. Sensory receptors

  3. The nervous system

  4. Effector organs
• Stimuli


  • Vibrating phone
• Sensory receptors


  • Eyes
  • Ears
  • Nose
  • Tongue
  • Skin
• Interaction system


  • Receptors receive stimuli
  • Central nervous system (CNS) process the information
  • Central nervous system (CNS) elaborates an answer
  • Effector organs execute the motor response (movement)
• Neurons


  • Highly specialised cells that have lost the ability to divide
  • They transmit the nerve impulses along their membrane
• Neurons


  • Dendrites: short cell proyections with many branches. Most neurons have multiple dendrites
  • Soma: contains the nucleus and most of the cytoplasm
  • Axon: long cell proyection, only branched at the end. There is usually only one

  
• Glial cells


  Different cells that support, nourish and protect neurons

  
• Nerve impulses


  • When a neuron is excited, a nerve impulse is generated. This nerve impulse is transmitted in the form of an electric current
  • When the nerve impulse reaches the end of the axon, it is transmitted to the next neuron via the synapse
• Astrocytes


  • Involved in neuron nutrition
  • They also help in the connections between two neurons (synapse)
  • They act as supporting cells
• Oligodendrocytes


  • They are only in the Central Nervous System (CNS)
  • They form an insulating coat called the myelin sheath, that helps in the transmission of the nerve impulses
  • They wrap around the axons of several neurons

  
• Schwann cells


  • They are only in the Peripheral Nervous System (PNS)
  • They form the myelin sheath, that helps in the transmission of the nerve impulses
  • They wrap around part of the axon of one neuron

  
• Microglia


  • They are part of the immune system
  • They come from the blood and defend the nervous system
• Nervous system


  The nervous system is divided in two parts: the central nervous system (CNS) and the peripheral nervous system (PNS)

  
• Central nervous system (CNS)


  • The central nervous system is formed by the brain and the spinal cord
  • Both protected by the skull and the spinal column

  
• Matter in the central nervous system

  • Grey matter: neuron somas and dendrites
  • White matter: neuron axons covered in the myelin sheath

  
• Meninges


  • Protective membranes of connective tissue that surround the CNS
  • Dura mater (outside)
  • Arachnoid mater (middle)
  • Pia mater (inside)
  • Between arachnoid mater and pia mater there is a cerebrospinal fluid, which acts as a cushion
• The brain


  • The brain is formed of the cerebrum, the cerebellum, and the brain stem

  
• Cerebrum


  • Cerebrum is divided in two cerebral hemispheres (right and left), connected by the corpus callosum
  • The outer layer of the cerebrum is the cerebral cortex, and the inner part is the limbic system
• Cerebral cortex


  • Receiving interpreting and processing information from the sense organs
  • Initiating voluntary motor responses
  • Intellectual and mental functions (intelligence, language, choices...)
  • Frontal lobe
  • Parietal lobe
  • Occipital lobe
  • Temporal lobe

  
• Limbic system


  • Emotions, feelings, basic instincts (hunger, thirst, sexual desire...)
  • Regulation of the internal stability (homeostasis)
  • Thalamus (controls the information to the cortex)
  • Hypothalamus (regulates the endocrine system)
  • Hippocampus (learning and short-term memory)
  • Amygdala (related with fear and violence)

  
• Cerebellum


  • Balance
  • Motor coordination and precision
  • Learned movements
• Brain stem


  • Regulation of the autonomic functions: heartbeat, respiratory movements, blood pressure, etc.
• Spinal cord


  • Conduit function: transmit information
  • Reflex function: involuntary motor responses
  • Grey matter on the inside, and white matter on the outside
  • Central canal filled with cerebrospinal fluid
• Peripheral nervous system (PNS)

  • The PNS consists of the nerves and nerve ganglia
  • Ganglia are a cluster of nerve cell bodies (somas)
  • Nerves are a group of axons, isolated by their myelin sheath and protected by connective tissue

  
• Nerves


  • Depending on the information they transmit: sensory, motor, mixed
  • Depending on where they emerge from the CNS: cranial nerves (12 pairs), spinal nerves (31 pairs)

  
• Somatic nervous system


  Connects the CNS to skeletal muscles. Regulates voluntary acts and reflexes

  
• Autonomic nervous system


  • Connects the CNS to smooth muscles and endocrine glands. Regulates involuntary functions (heartbeat, glands secretion, respiration, digestion...)
  • Parasympathetic: situations of rest and calm
  • Sympathetic: emergency situations (fight-or-flight response)