T1 L3: Topography of the brain Flashcards
what does neurulation mean?
development of the brain
describe the process of neurulation
- Neuroectoderm cells receive inductive signals from notochord
- Cells thicken to form neural plate
- Lateral neural plate margins fold inwards to form neural tube
- embryonic day 20
look at slide 2 to label slide
how was it
how does the nervous system develop
neural crest cells differentiate into:
1) Neurons and glia of the sensory and autonomic nervous systems
(2) Cells of the adrenal gland
(3) Epidermis
(4) Skeletal/connective tissue of the head
Mantle layer
- Becomes brain parenchyma
Ependymal layer
- Lines ventricles
Lumen
- Becomes ventricles + central canal
embryonic day 24
describe some neural tube defects
Anencephaly (fatal)- Failure of anterior neuropore to close
Spina bifida- Failure of posterior neural tube to close
leads to open vertebral canal
describe the difference between spina bifida occulta and spina bifida cystica
1) spina bifida occulta: hidden, vertebral arch defect only
2) Spina bifida cystica -meningocele = meninges projects out
describe the primary vesicles of the brain
In order:
Prosencephalon = forebrain
mesencephalon= midbrain
rhombencephalon= hindbrain
describe the secondary vesicles of the brain and what embryonic day it derives from
- day 36
- Telencephalon-cerebral hemispheres
optic vesicles- eyes
diencephalon = thalamus/hypothalamus
metencephalon = pons/cerebellum
myelencephalon = medulla
go through slides 1-7 especially the diff planar views of the brain
how was it
describe and identify gray and white matter (slide 8)
gray: mainly neuronal cell bodies (e.g. cerebral cortex, brain nuclei)
White matter - mainly myelinated axons
describe what the telencephalon comprises of
Comprises the cerebral hemispheres/cerebral cortex, components of the limbic system and the basal ganglia
describe and identify the division of the cerebral hemispheres into lobes
slide 10 how was it
give some features of the cerebral CORTEX
Outer layer of cerebral hemispheres
Folded to form gyri and sulci
label the precentral gyrus and postcentral gyrus as well as their main feature
pre- motor
post- sensory
slide 11
what is the lateral sulcus and identify it
divides temporal from parietal lobe)
slide 11
what I the majority of the cortex involved with
in association (perception of world) and cognition
LABEL some functional areas of the cortex
- sensory: auditory,olfactory, visual, somatosensory
motor: primary motor cortex, premotor cortex, motor speech
12
describe the corpus callosum and label
13-
white matter tract linking cerebral hemispheres
describe 2 deep brain structures
Limbic system
- Involved with emotion and memory
Basal ganglia:
- Involved in the control of posture and voluntary movement
what are deep brain structures
-interaction of white and gray matter deep to cerebral hemispheres to form neural pathways that are interconnected
what regions of the brain does the limbic system consist of
- Limbic system spans the telencephalon and diencephalon
includes: fornix, cingulate cortex, amygdala, hippocampus, (hypothalamus , mamillary bodies )
describe the fornix
The fornix is a semi-circular white matter tract connecting the hippocampus with the mammillary bodies
consist of : body of fornix, mamillary body, amygdala, hippocampus
describe the hippocampus
- the hippocampus looks like a sea horse
- consists of the fornix, pes (foot hippocampus) and sits in the floor of lateral ventricles
talk through the terminology of the basal ganglia
Corpus striatum
- caudate nucleus, lentiform nucleus- putamen, globus pallidus
describe the structures of the basal ganglia
Lentiform nucleus is lens
shaped
Caudate nucleus is C-shaped and sits in wall of lateral ventricle
describe the basal ganglia
-Lentiform nucleus sits lateral to caudate nucleus
describe the capsules
-internal capsule forms major white matter tract
describe the diencephalon
-comprises the thalamus and hypothalamus
describe the thalamus
Paired structure
- Relays sensory information to the cortex
- Involved with voluntary movement, personality and consciousness
describe the hypothalamus
Inferior to thalamus
Homeostasis:
-Coordinates ANS and endocrine responses
- Involved in thermoregulation, feeding, drinking, circadian rhythms
- Receives inputs from limbic system24-25
what do the mesencephalon and the rhombencephalon form
- the brainstem and cerebellum
midbrain- mesencephalon
pons & medulla- rhombencephalon
what does the brainstem contain
- Cranial nerve nuclei within all three regions
- Vital respiratory and cardiovascular centres
- Vomiting centre
- Nuclei involved with motor control, sleep
- White matter tracts
what are the main functions of the cerebellum
motor control:
- control of posture
- coordinating and planning limb movements
- control of eye movements
describe the Medulla oblongata
Pyramid:
Corticospinal tract – main voluntary motor pathway
Olive-
Formed by olivary nuclei
Motor relay to cerebellum
1-Cuneate tubercle,Gracile tubercle
- Nuclei form part of ascending tract
(see spinal cord lecture)
