Neuroanatomy Flashcards
What is anatomy?
The science of physical structure of animals/plants by dissection
What is the difference between Schwann cells and oligodendrocytes?
Schwann cells myelinate axons in the peripheral nervous system
Oligodendrocytes myelinate axons in the central nervous system
Define ventral and dorsal
Ventral = underside Dorsal = upper side or back
Where are axonal tracts found?
In the white matter
Define viscera
The internal organs in the main cavities of the body
What is the neural tube and how is it formed?
The embryo’s precursor to the nervous system. It is formed by the infolding of endoderm and will go on to form the brain and spinal cord by expanding at the front end
What is cerebrospinal fluid? How is it made, where is it found and what does it do?
It’s a clear, colourless fluid found in the brain and spinal cord. It’s produced by filtration of the blood in the chordis plexus in the ventricles of the brain and acts as a form of mechanical and immunological protection for the brain
What are the three types of glial cells and what do they do?
Astrocytes - form scar tissue after injury
Microglia - brain macrophages which clear infections
Oligodendrocytes - form insulating myelin sheaths around axons in the CNS allowing for rapid nerve impulse conduction
Define ganglion
A collection of neurons in the PNS
Define nerve
A bundle of axons in the PNS
Define tract
A collection of axons in the CNS with a common origin and destination
Define rostral
Situated near the front end of the body
Define caudal
Near the tail or posterior part of the body
What does expansion of the spinal canal go on to form?
The ventricles of the brain
What does the forebrain give rise to? (4)
Cerebral cortex
Basal ganglia
Thalamus
Hypothalamus
Where is the substantia nigra?
In the midbrain
Describe the meninges
A 3 membrane layer surrounding the spinal cord
From inner to outer:
Pia, arachnoid, dura
What is the cauda equina?
The ending of the spinal cord, a bundle of lumbar and sacral nerves
What are sulci and gyri?
Sulci are grooves in the brain, gyri are the ridges between them
What does the central sulcus do?
Divides the pre and post-central gyri
What are the four lobes of the brain?
Parietal
Temporal
Occipital
Frontal
What are the terms given for cutting the brain along its width and cutting along its length?
Widthways = Coronal sectioning Lengthways = Saggital secitoning
What is another name given to the pre-central gyrus?
The motor cortex
How are the four sections of the brain joined together?
The corpus callosum connects the two hemispheres of the brain
The internal capsule connects the top and bottom
What do the ventricles of the brain do?
Control the production of cerebrospinal fluid which adds protection, buoyancy and chemical stability
What is another name given for the post-central gyrus?
Somatic sensory cortex
What is a cluster of unmyelinated axons called?
A remax body
What is the difference between efferent and afferent fibres?
Efferent - away from the spinal cord
Afferent - towards the spinal cord
What is the difference between grey and white matter?
Grey matter is the part of the brain controlled by cell bodies. Grey appearance because of the nuclei.
White matter is a neuron of myelinated and unmyelinated fibres. It acts as a means of communication between grey matter areas
What regions of the spinal cord do spinal nerves connect to? (In order from top to bottom)
Cervical
Thoracic
Lumbar
Sacral
What are the roles of the different sensory fibres in humans?
A-alpha = Skeletal muscle proprioceptor A-beta = Skin mechanoreceptor A-delta = Pain and temperature C = Pain, temperature and itch
How can you tell where you’ve been touched?
Neurons in different body parts are linked to different areas of the post-central gyrus / somatosensory cortex
What are the two branches of the autonomic nervous system? What do they do and what neurotransmitters do they use?
Parasympathetic and sympathetic
Parasympathetic maintains homeostasis at rest using ACh
Sympathetic prepares the ‘flight-or-fight’ response using adrenergic synapses
What is the posterior pituitary and are the main hormones it secretes?
An extension of the hypothalamus via the infidibulum
Vasopressin (ADH) and oxytocin
What is a motor unit composed of?
An alpha motorneuron and the group of fibres it innervates
Input to alpha motor neurons can either be ventromedial or lateral. What is the difference between the two?
Ventromedial pathways control posture and locomotion
Lateral pathways control voluntary movement and are controlled by the cortex (corticospinal tract)
Where is the hippocampus and what is it important for?
It is found in the medial temporal lobe and is important for declarative memory i.e. memory of facts and events
What areas make up the limbic system and what is the circuit used for?
The cinglulate cortex, hippocampus and amygdala
The circuit is involved in emotions
