Boards Part I - Spinal Anatomy

What gives rise to all neurons and supporting cells?

Ectoderm

What gives rise to the vertebra?

Sclerotome - part of somites/mesoderm

What induces the ectoderm to form neuroectoderm (remnant IVD as “nucleus pulposus)?

Notocord

What forms the nerural plate (neuroectoderm)?

Ectoderm

What forms the neural groove, which houses the spinal cord and brain vesicles?

Neural plate

What will the neural plate (brain cells) develop into?

“MOANER”: “don’t be a moaner about the neural plate”

• Macroglial cells

  • Oligodendrocytes

  • Astrocytes

• Neurons of the CNS

• Ependymal cells

• Retinal cells

What does the neural crest develop into?

Anything the neural plate doesn’t: everything but “MOANER”

What forms the lining of the digestive tube and its associated structures: division of foregut/midgut, liver and pancreatic buds?

Endoderm

What makes up the primitive gut?

Foregut, midgut, hindgut, allaintois

What is found in the foregut?

Glands of buccal cavity, esophagus, stomach, pharyngeal pouches & pharynx

What is found in the midgut?

Duodenum, jejunum, appendix & part of the transverse colon

What is found in the hindgut?

Part of the transverse colon, descending colon, sigmoid colon, rectum, and upper anal canal

What is found in the allatois?

Urinary bladder, vagina, urethra, prostate and urethral glands

What do somites form?

The sclerotome

• Forms vertebral column (cartilage & bone)

• Mytome (muscle)

• Dermatome (skin)

What does the embryonic structure, foramen ovale become in an adult?

Fossa ovalis - between the atria of the heart

What does the embryonic structure, ductus arteriosus become in an adult?

Ligamentum arteriosum - bypasses lung pulmonary trunk to arch of aorta

What does the embryonic structure, ductus venosum become in an adult?

Ligamentum venosum - bypasses sinusoids of fetal liver

What does the embryonic structure, umbilical vein become in an adult?

Ligamentum teres - round ligament

What does the embryonic structure, umbilical artery become in an adult?

Medial umbilical ligaments

What does the embryonic structure, urachus become in an adult?

Remnant of duct of allantois

What is the function of simple squamous epithelium?

Filtration/diffusion - capillaries, alveoli, glomeruli

What is the function of ciliated epithelium?

Circulate, move, sweep/clean - brain vesicles, oviduct, lungs

What is the function of ciliated pseudo stratified epithelium?

Lining - trachea, upper respiratory tract

What is the function of non-ciliated pseudo stratified epithelium?

Membrane - vas deferens

Which CN rises from branchial/pharyngeal arch 1?

Mandibular branch of CN V (V3)

What skeletal structures rises from branchial/pharyngeal arch 1?

Malleus (Meckel’s cartilage), incus (quadrate cartilage)

Which muscles rises from branchial/pharyngeal arch 1?

Muscles of mastication and jaw-CLOSING muscles

Which CN rises from branchial/pharyngeal arch 2?

CN VII/Facial

Which skeletal structures rise from branchial/pharyngeal arch 2?

Stapes, styloid

Which muscles rise from branchial/pharyngeal arch 2?

Muscles of facial expression, jaw-OPENING muscles, stylohyoid, stapedius

Which CN rises from branchial/pharyngeal arch 3?

CN IX/glossopharyngeal

Which skeletal structures rise from branchial/pharyngeal arch 3?

Cornu, hyoid

Which muscles rise from branchial/pharyngeal arch 3?

Stylopharyngeus

Which CN rises from branchial/pharyngeal arch 4?

CN X/superior laryngeal branch

Which skeletal structures rise from branchial/pharyngeal arch 4?

thyroid cartilage, cricoid cartilage

Which muscles rise from branchial/pharyngeal arch 4?

Pharyngeal, cricothyroid, levator palatine

Which CN rises from branchial/pharyngeal arch 6?

CN X/inferior (recurrent) laryngeal branch

Which skeletal structures rise from branchial/pharyngeal arch 6?

Arytenoid, corniculate cartilage, cuneiform cartilage

Which muscles rise from branchial/pharyngeal arch 6?

Laryngeal

Which cells are the “glue” for neural tube cells and give rise to astrocytes and oligodendrocytes?

Glioblast

Which cells are the most numerous cells in the CNS and act like connective tissue, part of the blood brain barrier and forms “scar-like” tissue in injury?

Astrocytes

Which cells are quite numerous (less than astrocytes) and FROM myelin around the CNS?

Oligodendrocytes

Which cells line the CNS, ciliated and make “leaky” barrier between CSF and CNS?

Ependymal cells

Which cells are phagocytes and there are not many?

Microglia aka Gitterzellen

Which cells make neurons?

Neuroblast

What makes up the CNS?

Brain and spinal cord

What are the most common neurons?

Multipolar

What makes up grey matter?

Cell bodies and dendrites

What makes up white matter?

Myelinated axons

What are the macroglia in the CNS?

Astrocytes and oligodendrocytes

What are the primary vesicles of the brain?

Prosencephalon, Mesencephalon, Rhombencephalon

What are the secondary vesicles of the prosencephalon?

Telencephalon, diencephalon

What are the secondary vesicles of the mesencephalon?

Mesencephalon

What are the secondary vesicles of the rhombencephalon?

Metencephalon, myelencephalon

What are the structures found in prosencephalon?

Forebrain, thalamus, hypothalamus, pineal, lamina, mammillary body and posterior pituitary

What are the structures found in mesencephalon?

Midbrain

What are the structures found in rhombencephalon?

PONS & cerebellum, medulla oblongata

What are the CN found in prosencephalon?

I & II

What are the CN found in mesencephalon?

III & IV

What are the CN found in rhombencephalon?

V, VI, VII, VIII, IX, X, XI, XII

What is the most common location for a cerebral vascular accident (CVA)?

Middle cerebral artery

Which artery branches provide blood to posterior roots of the spinal cord?

Posterolateral longitudinal artery trunks (PLLAT) aka posterior spinal artery

What are the lateral apertures of the brain?

Foramina of Luschka

What is the median aperture of the brain?

Foramen of Magendie

What are the nuclei of the telencephalon?

Caudate, putamen, globus pallidus, basal ganglia

What are the nuclei of the mesencephalon?

Substantia nigra and subthalamic

What are the nuclei of the corpus striatum?

Head of the caudate and putamen

What are the nuclei of the lentiform nucleus?

Globus pallidus (medial) and putamen (lateral)

What makes up the brainstem?

Medulla oblongata, pons and midbrain

How much CSF is flowing in an adult?

140-270 ml

What is the order of the meninges?

Pia, arachnoid (spider), dura mater = think PAD

What produces CSF?

Choroid plexus

What resorbs CSF?

Arachnoid granulations

How much CSF is found in the ventricles?

Approximately 25ml

What produces chorea (quick movements)?

Atrophy or damage of the basal ganglia

How does Parkinson’s develop?

Neuronal degeneration of the substantia nigra

How many pairs of spinal nerves are there?

31

What is the Bell-Magendi Law?

Dorsal roots = sensory afferents, ventral roots = motor efferent fibers

Where does the spinal cord terminate?

L1/2

What is the end of the spinal cord?

Conus medullaris

What is the “Horse’s tail”, roots for lumbar, sacral and coccygeal nerves through lumbar cistern forming the “tail”?

Cauda equina

Where is the CSF exchange between 3rd and 4th ventricles?

Cerebral aqueduct of Sylvius

What is the function of the cerebellum?

Integration of “momentary” static muscle contraction, joint tension, visual & auditory input regarding equilibrium

What is the most common cell in the cerebellum?

Purkinje (grey matter neuron cell type)

What are the cerebella nuclei: from medial to lateral?

“Flowers Grow Every Day”:

• Fastigial

• Globus

• Emboliform

• Dentate

Which nuclei is lateral vestibular?

Deiter’s nucleus

What nuclei in the forebrain has ACH?

Meynert;s nucleus

Which nuclei is found in the medulla oblongata, serotonin?

Raphe nuclei

Which nuclei is part of the corpus striatum?

Lenticular nuclei

What determines an UMNL vs LMNL?

UMNL = brain → down to anterior horn cell

LMNL = anterior horn cell → out to periphery

What are the expected motor responses due to an UMNL?

Increase responses:

• (+) pathological reflexes/Babinski

• Increased muscle tone

• Spasticity

• Hypertrophy

• Clonus

• Increased DTRs

• Decreased superficial reflexes (BL) = EXCEPTION

What are the expected motor responses due to an LMNL?

Decrease responses:

• No pathological reflexes/Babinski

• Decreased muscle tone

• Flaccidity

• Atrophy

• Fasciculations

• Decreased DTRs

• Decreased superficial reflexes (UL)

What do the different parts of the spinal “horn” carry?

Posterior horn = sensory

Anterior horn = motor

Lateral horn = sympathetics/thoracics

Which ways do the sensory afferent pathways go?

Ascending - going to the brain

Which ways do the motor efferent pathways go?

Descending - going to the spinal cord

What kind of tract are the corticospinal, reticulospinal, tectospinal, rubrospinal and vestibulospinal?

Descending, motor

What kind of tract are the lateral spinothalamic, anterior spinothalamic, dorsal columns (fasciculus gracilis & cuneatus), posterior spinocerebella, anterior spinocerebellar, spinotectal, spinoreticular?

Ascending, sensory

Which tracts are apart of the pyramidal system?

Lateral and anterior corticospinal tracts

Which tracts are apart of the extra-pyramidal (unconscious) system?

Reticulospinal (pontine and medullary), tectospinal, rubrospinal (red), vestibulospinal

Which tract functions for precise and skilled movement, like threading a needle or writing?

Corticospinal (lateral and anterior) tracts - descending motor