Flashcards in bms 236-Developmental Neuro Deck (259)
Do reptilian brains have a cerebellum? Prefrontal cortex? Nerves sorted into special sensory modules e.g. vision?
Yes- sensory modules
Mammalian brains now have a limbic system, this includes..?
Thalamus: integrates sensory information and allow them to be used together. tells signals where to go.
Hypothalamus: regulate the endocrine system and body temp etc.
Hippocampus &amygdala- crude memory
Changes in the human brain?
Larger cortex, e.g. prefrontal cortex allowing for higher level thinking.
Development of the Neocortex
Name where the 4 lobes are? And what for?
Frontal-personality (at front)
Temporal- Deep inside e.g. Hippocampus (side near temples)
Parietal- mathematical (large in einstein- parents must have been so proud)(at top near back (where parents would tap you on the head))
Occipital- visual (opticians) (back of head)
Difference between Brocas area and Wernicke's?
Brocas- speech making (e.g think of the girl who couldnt speak- brocas aphasia)
Wernicke- grammatical rules (e.g. the man who made no sense)
Brain has plasticity throughout life, what is one area this is very evident in?
Hippocampus- making new memories
What do single celled organisms share with our current nervous system?
Receptive and responsive to environment.
Light sensitive eyespot
They then respond to this by moving using flagella.
What comes with becoming multicellular?
In a sea sponge flow rate of water is regulated by specialised muscle like ..... which respond to stretch receptors.
The first neurons probably developed from ....... cells in the ectoderm. These then migrated ...
Gene expression in a cell is governed by which two things?
Intrinsic factors e.g transcription factors
Extrinsic factors e.g morphogens
How does the neurogenic region arise?
It starts as ectoderm but bmp signalling is inhibited in certain cells and these become neural. This bmp inhibitor is either Chordin or Noggin, and is expressed by the organiser/node on the dorsal side.
The developing blastula secretes bmp which induces ectoderm cells to become epidermal skin cells.
What is the invertebrate homologue of chordin and Bmp?
These are on the opposite side, so whereas Chordin is expressed Dorsaly, sog is ventral
What is the spermanns organiser?
Region of mesoderm that induces formation of the neural plate from endoderm. Under the influlence of transcription factors such as Gse the organiser expresses BMP inhibitors
The primary motor cortex projects via the ...... tract to the .... The middle level is the ....
what does the primary motor cortex do?
It regulates motor tracts originating in the brain stem
What does the brainstem do in motor control?
It regulates movements, and controls distal limbs (as well as autonomic system)
What does the spinal cord do in motor control?
Reflexes, either monosynaptic or poly, and automated motor movements such as walking
Fun fact: Why can't babies walk early on?
Their corticospinal tract isn't fully myelinated.
Hierarchical arrangement of the motor system?
Primary motor cortex to brainstem is via Upper motor
neurons, and brainstem to spinal cord is via Lower motor neurons.
Artificially stimulating the PMC only causes jerks so what two other systems are involved? Where do these project to?
Cerebellum: Mostly PMC (via thalamus), but also directly to brainstem,
Basal Ganglia: PMC (UMNs)
What does the basal ganglia and cerebellum do in terms of motor control?
Receives info from many different areas, projects to the PMC via thalamus. Monitors the commands going down to ensure appropriate for the environment. If not appropriate, send correction signals to motor cortex. Basal ganglia terminates excess movements.
How was the motor cortex found?
1870- electrical stimulus to different areas caused movements on opposite sides of the body.
Where is the motor cortex?
Brodmanns area 4, located in the frontal lobe just before the central sulcus. It is topologically arranged (think man with big hands and lips)
what do Upper motor neurons do?
From cerebral cortex or brainstem. Project to the lower motor neurons via interneurons, for planning, initiating and directing movements
What are the two upper motor neuron pathways?
Direct: UMNs axons from the cerebral cortex Input to LMN
Indirect: UMNs axons from brainstem input to LMNs. Inputs from cerebellum and basal ganglia also join to these.
summary: UMN- Interneurons- LMNS- muscle
change in the muscle tension is detected by?
Golgi tendon organ
Change in muscle length Is detected by?