Neuro Step 1 Flashcards
In what disorders are dopamine levels increased?
schizophrenia
In what disorders are dopamine levels decreased?
depression & Parkinson disease
What are the four major dopaminergic pathways?
Mesocortical pathway, mesolimbic pathway, nigrostriatal pathway, tuberoinfundibulnar pathway
Describe the mesocortical pathway. What is the result of blocking this?
Ventral tegmental of the midbrain -> cortex
increased negative symptoms of schizophrenia
Describe the mesolimbic pathway. What is the result of blocking this?
Ventral tegmental of midbrain -> limbic system
Relieves positive symptoms of schizophrenia
Describe the nigrostriatal pathway. What is the result of blocking this?
Substantia nigra pars compacta -> neostriatum
Parkinson Disease
Describe the tuberoinfundibular pathway. What is the result of blocking this?
Arcuate nucleus of hypothalamus -> pituitary
Increased release of prolactin from anterior pituitary (hypogonadism, which manifests as amenorrhea in women and decreased libido in men)
In what disorders are norepinephrine levels increased?
anxiety/mania
In what disorders are norepinephrine levels decreased? Where is NEpi produced?
depression
locus ceruleus
In what disorders are serotonin levels decreased? Where is serotonin produced?
anxiety and depression
Raphe nucleus
What disorder is associated with decreased levels of ACh? Degeneration of what structure would be found?
Alzheimer’s Disease
basal nucleus of Meynert
In what disorders are GABA levels decreased? Where is it produced?
anxiety & Huntington's disease nucleus accumbens (produced from glutamate and VitB6)
Forebrain (prosencephalon) develops into what?
Telencephalon -> cerebral hemispheres, basal ganglia, hippocampus, amygdala
Diencephalon -> thalamus, hypothalamus, optic nerves, and tracts
Midbrain (mesencephalon) develops into what?
Mesencephalon -> midbrain
Hindbrain (rhombencephalon) develops into what?
Mesencephalon -> Cerebellum & pons
Myelencephalon -> medulla
What cartilage, muscle, and nerve structures develop from the first pharyngeal arch?
M&T structures Cartilage - Meckel's cartilage - mandibular ligament - mandible - malleus & incus Muscle - Muscles of Mastication - masseter - medial pterygoid and lateral pterygoid muscles - temporalis mylohyoid tensor tympani tensor veli palatini Anterior 2/3 of tongue Nerves Mandibular & Maxillary branches of the trigeminal nerve
What disorder happens if neural crest cells fail to migrate to the 1st pharyngeal arch?
Treacher Collins syndrome
What cartilage, muscle, and nerve structures develop from the second pharyngeal arch?
S structures Cartilage - Stapes Styloid process Stylohyoid ligament Lesser horn of the hyoid Muscle - Muscles of facial expression Stapedius Stylohyoid Nerve - CN Seven (innervates the muscle of facial expression)
What cartilage, muscle, and nerve structures develop from the third pharyngeal arch?
"pharyngeal" Muscle - stylopharyngeus Nerves - Glossopharyngeal (CN IX)
What cartilage, muscle, and nerve structures develop from the fourth and sixth pharyngeal arches?
“cricothyroid & larynx”
Cartilage -
cricoid cartilage, thyroid cartilage, cartilage of the larynx
Muscles -
cricothyroid muscle (4th)
pharyngeal muscles (swallowing) (4th)
rest of the laryngeal mm. (speech) (6th)
Nerves -
CN X
superior laryngeal (swallowing and cricothyroid m)
recurrent laryngeal nerve (6th arch) (speech)
Forebrain anomalies
meroencephaly anencephaly meroanencephaly - incompatible with life holoprosencephaly -> hemispheres of the brain fail to separate at midline
What causes cycloplegia and cleft lip & palate?
sonic hedgehog gene mutations
severe fetal alcohol syndrome
patau syndrome (trisomy 13)
What is Dandy Walker syndrome?
enlarged posterior fossa
cerebellar vermis fails to develop
Dilation of the 4th ventricle
associated with hydrocephalus & spina bifida
What are Chiari malformations?
Hindbrain abnormality -> part of the cerebellum herniates downward through foramen magnum
Chiari I - mildest; only tonsils herniate; may cause syringomyelia
Chiari II - lombosacrale myelomeningocele, more significant herniation of tonsils and vermis; can have hydrocephalus