Central Nervous System (CNS) Flashcards
What is the central nervous system composed of?
Brain
Spinal cord
What do the brain and spinal cord lie within?
The skull and the vertebral canal, respectively
What are meninges?
Membranous coverings of the brain and spinal cord
What are the 3 layers of the meninges
Dura mater
Arachnoid membrane
Pia Mater
Which is the most innermost layer of the meninges?
Pia Mater
What are the segments of the spinal cord?
Cervical Thoracic Lumbar Sacral Coccygeal
Describe the spinal cord organisation (white matter and grey matter)
Grey matter: on the inside. Contains neuron cell bodies
White matter: on the outside. Contains nerve axons
Describe dorsal horn grey matter
- In dorsal or posterior part of spinal cord
- Location of first order afferent neurons terminals
- Contains cell bodies of second order sensory neurons
Describe ventral horn grey matter
- In ventral or anterior part of the spinal cord
- Contains cell bodies of motor neurons
- Motor neuron axons leave cord via ventral nerve roots
Why is there relatively more white matter in the cervical and thoracic regions compared to the lumbar and sacral regions?
Arrangement of tracts - axons become bundles moving down the spinal cord
Which components make up a reflex pathway?
Sensory neuron
Interneuron (not always)
Motor neuron
Why are reflex pathways so fast?
Very fast responses because they don’t require complex processing
Bypasses higher level processing
What does the jaw reflex do?
Protects teeth from breaking when we chew on something hard (e.g. popcorn kernel)
Describe the arrangement of white matter and grey matter in the brain
White matter on the inside (corpus callous), grey matter on the outside (cerebral cortex)
Which regions make up the forebrain?
Cerebrum
Diencephalon
What is the midbrain responsible for?
Visual and auditory reflexes
Pain control
What is the hindbrain responsible for?
- Vital centres regulating breathing, heart, blood vessels, etc (medulla)
- Control of balance and posture (cerebellum)
What is the diencephalon made up of?
Thalamus and hypothalamus
What happens in the thalamus?
Sensory processing
What role(s) does the hypothalamus have?
- Role in homeostasis e.g. thermoregulation
- Hormone production
- Associated with pituitary gland and its hormones
- Circadian rhythms
- Motivation
- Emotional responses, stress
What is the cerebrum (part of the forebrain) important for?
- Sensory and motor functions
- Language
- Memory
- Perceptions
- Sensory/motor integration
- Emotions
Which lobe is the somatosensory cortex located in?
Parietal
Which lobe is the visual cortex located in?
Occipital
Which lobe is the auditory cortex located in?
Temporal
Which lobe is the taste cortex located in?
Parietal
