compendium 9

• Where is the spinal cord located?


  -extends from the foramen magnum to the first or second lumbar vertebrae
• What are the regions of the spinal cord?

  -cervical

  -thoracic

  -lumbar

  -sacral

  -coccygeal

  -31 pairs of spinal nerves
• Describe the meninges


  -connective tissue that surrounds the brain and spinal cord

  -contains CSF

  -forms partitions inside the skull

  -protects
• What are the structures of the meninges?

  -Dura mater: outer subdural space

  -Arachnoid mater: middle layer, contains subarachnoid space- CSF and blood vessels

  -pia mater: many small blood vessels, inner most layer
• What is the organisation of neurons the spinal cord?

  -sensory neurons travel through the dorsal roots

  -motor neurons travel through the ventral roots

  -spinal nerves have both sensory and motor neurons
• cell body locations in the spinal cord


  -motor neuron cell bodies are in the horns of the grey matter

  -somatic are in the ventral horn and autonomic are in the lateral horn
• Describe the nerve coverings


  -connective tissue, 3 layers

  -Endoneurium: surrounds each axon, Schwann cells also here

  -perineurium: surrounds a fascicle (group of axons

  -Epineurium: surrounds several fascicles i.e nerve
• What are the three main regions of the brain?


  forebrain, midbrain, hindbrain
• What are the structures within the forebrain?


  -cerebrum and diencephalon
• What are the structures within the hindbrain?


  -pons

  -medulla

  -cerebellum
• What are the functions of the medulla?


  -centre for automatic reflexes that maintain homeostasis

  -cardiovascular; regulates HR, force of contraction, diamter of vessels

  -respiratory centre, regulates rate/depth of breathing

  -other reflexes such as swallowing, hiccups, vomiting, sneezing
• What are the functions of the midbrain?


  -receives and integrates visual, auditory and tactile sensory input

  -then initiates movements of the head/eyes in response

  -controls eye movement
• What are the functions of the cerebellum?


  -helps control locomotion

  -fine motor control

  -posture and balance control
• What are the structures within the diencephalon?


  -thalamus

  -hypothalamus

  -subthalamus

  -epithalamus
• What are the functions of the thalamus?


  -sensory relay centre

  -influences moods and actions associated with strong emotions
• What are the functions of the hypothalamus?


  -central controller of the endocrine system

  -the infundibulum connects to the pituitary gland

  -autonomic, endocrine, muscle control, body temp reg, sleep-wake cycle, behaviour
• What are the convolutions/folds of the cerebral hemispheres?


  -gyri: folds or bumps

  -Sulci: grooves between the gyri

  -Fissures: deep groves

  Func: increased surface area for neurons
• What are the lobes of the brain/cerebrum?

  frontal, parietal, occipital, temporal
• What are the other structures in the cerebrum?


  -pre-central gyrus: primary somatic motor cortex

  -post-central gyrus: primary somatic sensory cortex (somatosensory)

  -Insula/Insular lobe: receives and evaluates taste information
• Grey and white matter in the brain


  Grey matter located in the outer cortex, white matter in the deeper tissues
• Describe the frontal lobe

  motor function, motivation, planning, regulation of mood, sense of smell
• Describe the parietal lobe


  -receives and evaluates sensory, but not special senses
• describe the occipital lobe


  -receives and integrates visual input
• describe the temporal lobe


  -receives and evaluates input for special senses such as smell and hearing. Role in memory
• describe the limbic system


  -'emotional brain'

  -memory

  -motivation, emotion, learning

  -also influences autonomic and endocrine systems
• describe the ventricles of the brain


  -4 continous ventricles

  -lined with ependymal cells

  -CSF produced in ventricles, circulates
• describe cerebrospinal fluid (CSF)


  -fluid found around the brain and spinal cord

  -most CSF is produced by choroid plexus

  -protects brain and spinal cord; cushions; bathes

  -allows the brain to float within the cranial cavity

  -similar to blood serum but without proteins
• spinal nerves


  -31 pairs total

  -8 cervical

  -12 thoracic

  -5 sacral

  -5 coccygeal
• Where are the sympathetic nerves located?


  T1-L2 spinal segments "thoracolumbar division"
• Where are the parasympathetic nerves located?


  -4 cranial nerve nuclei

  -S2-S4 spinal segments

  
• Dorsal root ganglion


  a nodule on a dorsal root that contains cell bodies of sensory spinal nerve neurons
• spinal cord horns


  anterior horn, lateral horn, posterior horn
• transverse tracts


  connects cerebrum to cerebellum
• longitudinal tracts


  connect higher brain centres and the spinal cord
• describe the pons


  links your brain to your spinal cord. handles unconscious processes, such as your sleep-wake cycle and breathing. It also contains several junction points for nerves
• Where is grey matter located in the CNS and PNS?


  CNS: brain cortex and nuclei

  PNS: Ganglion
• Where is white matter located in the PNS and CNS?


  PNS: Nerves

  CNS: Nerve tracts
• Describe the conus medullaris


  the terminal end of the spinal cord which occurs at the L1 vertebral level in an adult
• What are ganglia/ganglion?


  clusters of cell bodies in the PNS, responsible for motor control and executive functions
• How does the cerebrum (CNS) and limbic system influence the ANS?

  -thoughts and emotions can influence ANS function through the hypothalamus