Revision

• Nervous System


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


  Carries sensory (afferent) information from skin/joints/muscles (efferent) to the brain
• Somatic Nervous System example

  • Ripping off a Band-Aid: The Brain sends messages via motor neurons (efferent) in the Peripheral Nervous System to hand muscles to rip Band-Aid off of leg. Then sensory receptors get sent from the leg skin tissue, then will send messages of pain via afferent sensory afferent neurons to the brain. The brain receives and processes this pain, and sends instructions via motor neurons to your facial muscles and vocal areas to scream "ow".
• Autonomic Nervous System


  Autonomous - self regulating, without conscious effort. Connects the CNS to the body's internal organs (heart, lungs, stomach, etc) and glands (sweat, salivary, adrenal etc.)
• Autonomic Nervous System


  • Sympathetic Nervous System
  • Parasympathetic Nervous System
• Sympathetic Nervous System


  Activates the flight, fight or freeze response. Activates internal muscles, organs and glands to prepare for action (vigorous activity or stressful/threatening situations) - adrenaline is released. Enhances survival by providing an immediate response - physiological response. Activated by a stressor or fear stimulus - heart beats fast, digestion slows, breath is fast and shallow, pupils dilate, blood pressure increase.
• Parasympathetic Nervous System


  Parasympathetic (rest and digest). Maintains internal body environment in a steady, balanced state. Counterbalances activities of sympathetic nervous system. Restores body to a state of calm. Dominates the sympathetic nervous system most of the time (involved in everyday activities). Takes longer to return the body to normal state (not immediate because hormones may still be in blood stream). Relaxation response: rest, think and restore; heart beats in slow rhythmic pattern, breath is full and slow, pupils of eyes shrink, gut is active (helps you digest and absorb the nutrients from your food), increased blood flow to gut, lungs and brain, hormones rush in lifting your mood and helping you to relax, conserves your energy.
• Enteric Nervous System


  The gastrointestinal tract also known as the the gut is the collection of organs and tissue that run from the mouth to the arms, primarily involved in digestion. Within the walls of the gut is the enteric nervous system (ENS) that keeps it functioning. The ENS contains 400-600 million neurons thar are involved in processes such as muscle contractions to process food along the gut, balancing gastric acid levels etc. The ENS has extensive, two-way connections with the CNS, and communicates with the brain to control digestion. The ENS can also function independently for some digestive processes.
• Brain Imaging Techniques


  • Magnetic Resonance Imaging (MRI)
  • Computerised Tomography (CT)
  • Positron Emission Tomography (PET)
  • Functional MRI (FMRI)
• Magnetic Resonance Imaging (MRI)


  Uses harmless magnetic fields to vibrate atoms in the brain's neurons and generate an image of the brain. More sensitive than CT. Clearer, more detail and can be in colour - more than others. No pacemaker or metal implants allowed. Shows horizontal and vertical slices. MRI takes longer than CT.
• Computerised Tomography (CT)


  Also called CAT scan. Uses x-ray equipment to scan the brain at different angles. Patient must be given a substance called contrast (highlights the blood vessels). X-rays are not very good for imaging tissue. Shows horizontal cross sections.
• Positron Emission Tomography (PET)


  Produces colour images showing structure, activity and function. Radioactive glucose is injected into the bloodstream and areas of the brain requiring more energy to 'light up'. PET scans show less detailed structure than MRI.
• Functional MRI (FMRI)


  Shows very detailed, precise structure and function. Detects and records brain activity by measuring oxygen consumption (no radiation). Very quick - seconds to take pictures instead of minutes. Assuming that active areas consume more oxygen.
• Neuroimaging techniques example


  • Neuroimaging techniques, such as PET and fMRI, have provided more detailed information regarding the structure and function of parts of the brain than did the first brain experiments. The information provided by PET and fMRI includes detailed information regarding the location in the brain of specific functions of the body and the extent to which different parts of the brain are active during certain activities. Although the first brain experiments provided some insights in this respect, this information was less detailed and objective.
• Brain Divisions


  • Forebrain
  • Midbrain
  • Hindbrain
• Forebrain


  Voluntary motor movements, complex cognitive activities, sensory processing, endocrine structures
• Forebrain


  • Cerebrum
  • Corpus Callosum
  • Cerebral Cortex
  • Thalamus
  • Hypothalamus
  • Amygdala
  • Hippocampus
• Cerebrum


  Containing two central hemispheres - thinking
• Corpus Callosum


  The connections between the two hemispheres, works to receive and process a range of sensory
• Cerebral Cortex


  Ultimate control and information processing centre. Coordinates cognition, perception, language, judgement and problem solving. Receives and processes motor and sensory information.
• Thalamus


  Relay centre for sensory information, filters information, attention
• Hypothalamus


  Regulates internal processes including; hormones, hunger, body temperature, thirst
• Amygdala


  Control of emotions
• Hippocampus


  Learning + memory
• Midbrain


  Motor movement + audio/visual processing
• Substantia Nigra


  Factor that produces dopamine (one key function of dopamine is movement + muscle control). Gathers auditory and visual sensory information. Nerve cell damage is linked to motor control (Parkinson's disease).
• Reticular Formation


  Responsible for arousal, consciousness and motor control
• Hindbrain


  Coordinates basic survival functions such as moving, heart rate, breathing + sleep. Autonomic functions.
• Pons


  Control of breathing, sleep + arousal
• Medulla


  Regulates autonomic functions; breathing, blood flow, levels of oxygen + carbon dioxide
• Cerebellum


  Stores procedural memories, coordinates voluntary movements, balance + posture
• Brain Lobes


  • Frontal Lobe
  • Parietal Lobe
  • Occipital Lobe
  • Temporal Lobe
• Frontal Lobe


  Sophisticated mental abilities; reasoning, planning, problem solving, decision making, symbolic thinking, attention, emotional regulation, personality, intelligence - association area. Initiates and controls voluntary movements to the muscles. The left lobe controls movements on the right side of the body and the right lobe controls movements on the left side of the body - contralateral. Areas at the top of the cortex control lower parts and vice versa. The amount of area on the motor cortex relates to precision/complexity of movement. This is known as homunculus the parts of the body that have fine motor skills and require more control have larger portion of the motor cortex. Broca's Area: Aphasia = Damage. Only located in the left hemisphere. Helps jaw and mouth movement for speech. Close to primary motor cortex. Plays a significant role in the production of coherent speech patterns.
• Parietal Lobe


  Receives and processes bodily information. Touch, temperature, bodily position, spatial position of limbs, severe muscle movement. Primary Somatosensory Cortex: Receives and processes sensory information from the skin and contralateral side of the body. Areas at the top of the cortex receive information from lower body parts and vice versa. The amount of area on the somatosensory cortex relates to the sensitivity of the body part - homunculus.
• Occipital Lobe


  Responsible for receiving and processing visual information. Primary Visual Cortex: Each hemisphere receives and processes half of the visual information. Left half of eye receives visual information from the right visual field and sends information to the left occipital lobe and vice versa. Left visual field - right hemisphere, right visual field - left hemisphere, right/left eye - both hemispheres.
• Temporal Lobe


  Responsible for auditory processing (soma), memory, facial recognition and emotional responses to information. Primary Auditory Cortex: Receives and processes auditory information from both ears (ipsilateral). Sounds of a different pitch will register in different areas. Wernicke's Area: Aphasia = Damage. Only located in left hemisphere. Close the the primary auditory cortex. Helps make sense of own and others sentence structure. Involved in understanding speech through processing sounds - meaning of language comprehension.
• Brain Hemispheres


  • Left Hemisphere
  • Right Hemisphere
• Left Hemisphere


  Language (reading, writing, speaking, comprehension). Logic, reason, arguments. Receives and sends information from right side of body. Sensory stimulus from right side of body. Motor control of right side of body. Speech, language + comprehension. Analysis + calculations. Time + sequencing. Recognition of words, letters + numbers.
• Right Hemisphere


  Spatial, visual thinking including faces. Receives and sends information from left side of body. Sensory stimulus from left side of body. Motor control of left side of body. Creativity. Spatial ability. Context/perception. Recognition of faces, places + objects.
• Brain Injuries


  • Acquired Brain Injury (ABI)
  • Traumatic Brain Injuries (TBI)
  • Non-traumatic Brain Injuries (N-TBI)