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Flashcards in neuroanatomy Deck (35)
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1
Q

Describe Neurulation in the embryo

A

Central part of ectoderm differentiates into the neural plate-forms neural tube in 4th week-differentiates along dorsal/ventral axis by growth signaling factors–>Shh (notochord) and BMP (ectoderm)

2
Q

Primary neurulation

A

involves invagination and columnarization of an existing epithelium. rest of the spinal cord (not sacral)

3
Q

Secondaty neurulation

A

characterized by condensation of mesenchyme (brown) to

form a rod, which then undergoes an epithelial transition to form the neural tube. Sacral part of column

4
Q

When and how does neural tube close?

A

during days 19-21. five separate waves of closure.
Begins in region of brain stem and upper spinal cord, followed by head & neck.
Final closure in caudal region where the sacral part of the spinal cord fuses with the rest of the
spinal cord

5
Q

What is Anencephaly

A

Lack of skull & cerebrum formation, with only a brain stem intact.
• Due failure of wave 2 closure

6
Q

Spina bifida

A

Incomplete formation of both the spinal cord and the overlying vertebrae which remain unfused and open:
spina bifida occulta, meningocele, myelomeningocele.
incomplete closure of caudal neuropore at junction of primary and secondary neurulation.

7
Q

CNS regions from dilation and flexure of neural tube

A

Hindbrain: medulla, pons( Myelencephalon, metencephalon)
Midbrain: Mesencephalon
Diencephalon: thalamus, hypothalamus, epithalamus
Telencephalon: cerebral hemispheres
Neural tube–> spina canal, ventricles

8
Q

Rostral

Caudal

A

Rostral – toward front of brain

Caudal – toward spinal cord

9
Q

Cephalic and Pontine Flexures

A

Cephalic flexure: Ensure that optical axes are at right angles to vertebral column. Related to cranial base flexion
Pontine flexure:Areas of 4th ventricle and pons enlarge. Cerebellum derived from edge of pons

10
Q

SPINAL CORD OVERVIEW

A

Grey matter area is divided into sensory, autonomic, and motor areas
White matter is divided into ascending (C) and descending (D) tracts

11
Q

GREY MATTER OF SPINAL CORD

A
Rexed’s lamina are functionally specific areas of 
gray matter
– Dorsal – sensory
– Intermediate – autonomic 
– Ventral - motor
12
Q

Dorsal horn

A

(sensory)
Afferents convey tactile, proprioceptive, pain and temperature sensations to neurons into lamina 2-5
Second order neurons send information to local spinal
areas as well as ascend to brain stem and thalamus

13
Q

Intermediate region

A

(autonomic) Site of preganglionic autonomic neurons (visceral motor, VM)

14
Q

Ventral horn

A

(motor) Efferent motor neurons project to skeletal muscle

groups

15
Q

WHITE MATTER OF SPINAL CORD

A

Separated into dorsal, ventral & lateral funiculi. Spinal tracts within white matter are formed by axons of ascending and descending neurons

16
Q

Funinculi: dorsal, lateral, ventral

A

Dorsal columns (cuneate & gracile fasciculi) carry tactile info to brain stem & thalamus
Lateral: corticospinal tract - major descending motor tract from cortex . Spinocerebellar tracts - tactile & proprioceptive information to cerebellum. Anterolateral system conveys pain and temperature to thalamus
Ventral: Anterior (ventral) corticospinal -descending motor pathways from cortex .vestibulospinal & reticulospinal - descending motor pathways from brain stem

17
Q

What does the Propriospinal tract do?

A

Surrounds grey matter and interconnects various spinal levels

18
Q

What does the brainstem contain?

A
regulatory centers for respiratory, cardiovascular, GI 
systems
• cranial nerves
• sensory and motor pathways 
• reticular formation
19
Q

Cerebellum

A

Cerebellar peduncles: input and output tracts between cerebellum & pons
Different regions regulate muscle coordination, motor planning & procedural memory, as well as balance
and eye movements

20
Q

MIDBRAIN contains?

A
Substantia nigra (dopamine), Periaqueductal grey (PAG)(Regulates pain / stress responses), Superior & Inferior Colliculi (Superior looks; inferior listens), Red nucleus
(descending motor pathway), Cerebral peduncle (sensory & motor pathways to and from spinal cord, brain stem and cortex)
21
Q

What is the DIENCEPHALON?

A

Nuclear regions
• Thalamus
• Hypothalamus (flanking third ventricle)
• Epithalamus contains pineal gland

22
Q

Thalamus?

A

Several nuclei that process & distribute

sensory & motor information to & from cerebral cortex

23
Q

Hypothalamus?

A
  1. Nuclei
  2. Pituitary
    – Anterior
    – Posterior
24
Q

Anterior pituitary

A

Derived from ectoderm primordia
Portal system of vessels extend from
hypothalamus into anterior pituitary

25
Q

Posterior Pituitary

A

Derived from neural tube

Neurosecretory neuronal axons extend into posterior pituitary to release hormones into blood

26
Q

Frontal lobe

A

Motor cortex: primary,
premotor, supplementary,
Broca’s speech area

27
Q

Parietal lobe

A

Somatosensory cortex:
primary, secondary,
association, Wernicke’s
language area

28
Q

Temporal lobe

A

Auditory cortex: primary,

secondary, association

29
Q

Occipital lobe

A

Visual cortex: primary,

secondary, association

30
Q

insula

A

Gustatory, visceral,
emotional cortex within
lateral sulcus/fissure

31
Q

central sulcus and lateral fissue

A

Central sulcus separates frontal from parietal lobes.

Lateral fissure separates frontal from temporal lobes

32
Q

reticular formation

A

nuclei in brain stem. sensory input–> project to cortex, libic, spinal cord. Particular NT.
Associated with wakefulness, arousal, attention, etc

33
Q

Basal ganglia

A

Caudate & putamen (striatum)
Globus pallidus (GP)(embedded in white matter)
Substantia nigra & Subthalamus (midbrain)

34
Q

LIMBIC SYSTEM

A

C-shaped cluster of structures that extends into temporal lobe
cortex (Orbital & medial prefrontal cortex, Cingulate gyrus, Parahippocampal gyrus), thalamic nuclei, Hippocampus, Amygdala, Ventral striatum (nuc accumbens)

35
Q

What do white matter axon bundles do in the brain?

A

interconnect cortical regions
sup. longitudinal & occipitofrontal
fasciculi interconnect cortices along longitudinal axis
Arcuate fibers interconnect local gyri
Corpus callosum interconnects left and right hemispheres