General Brain Structure [through development] Flashcards
4 brain components common across all mammals
- cerebrum
- diencephalon
- cerebellum
- brainstem
Fill in the missing labels
What is rostral & caudal
Rostral - towards nose
Caudal - towards tail
(based on midsaggital plane of rat brain)
Identify the plane
Coronal
Identify the plane
Horizontal
Identify the plane
Sagittal
What is ventral view?
From the bottom
What is dorsal view?
From the top
What is another name for Midbrain?
Mesencephalon
name the regions of the brain stem
what is the general function of the areas of the brainsteM & diencephalon
- Diencephalon:
Thalamus - relay & process sensory information
Hypothalamus - control emotion, autonomic function, hormone production - Mesencephalon - process visual & auditory data, reflexive somatic responses, maintaining consciousness
- Pons - relays sensory information to cerebellum & thalamus
- medulla oblongata - regulation of visceral functions, relays sensory info to rest of brainstem & thalamus
What is the general function of the spinal cord?
Sensory & motor conduit
* incoming sensory through dorsal root
* outgoing motor through ventral root
What is the PNS
Peripheral nervous system - anything outside the brain & spinal cord
What is the Somatic PNS?
- immervates skin, joints, muscles (involved in conscious activities)
What is the Somatic PNS?
- immervates skin, joints, muscles (involved in conscious activities)
What is dorsal root ganglia?
clusters of sensory neuronal cell bodies outside the spinal cord
What is the visceral PNS?
Innervates the internal organs, blood vessels, glands (part of autonomic NS)
What is the visceral PNS?
Innervates the internal organs, blood vessels, glands (part of autonomic NS)
What is afferent vs efferent
- Afferent = towards brain
- Efferent = away from brain
What is afferent vs efferent
- Afferent = towards brain
- Efferent = away from brain
What are the 3 meninges?
- Dura Mater - tough outer later
- Arachnoid Mater - “the spider web”
- Pia Mater - inner layer
Identify the meninges & spaces
What is notable about the subarachnoid space?
CSF flows through here & where it gets absorbed
What is CSF & its function
Cerebrospinal fluid
* highly filtered blood plasma (no proteins)
* provides mechanical support to the brain & gives chemical protection
What is choroid plexus?
tissue in ventricles that secretes CSF
What do the ectoderm, mesoderm & endoderm of an embryonic disc give rise to?
- Ectoderm - nervous sytem & skin
- Mesoderm - musculoskeletal system
- Endoderm - viscera
Name the parts of the embryonic disc
How does the neural tube develop?
Neural plate
↓
Neural groove
↓
Neural tube
What do the neural tube & neural crests develop into?
- Neural tube - CNS
- Neural crest - PNS
Identify these structures
Identify the 3 primary vesicles from which the entire brain develops
Identify differentiated areas of prosencephalon during neurodevelopment
What are the 4 ways the telecephalon develops into 2 cerebral hemispheres?
- Telencephalon grows posteriorly to overlie the diencephalon
- olfactory bulbs form
- cells of telencephalon walls divide and form various structures
- White matter systems develop (axons to and from diencephalon)
What are the 3 main white matter tracts that develop from the telecephalon?
- cortical white matter - association tracts, communication within 1 hemisphere
- Corpus callosum - commisural tracts, communication between the hemispheres
- Internal capsule - projection tracts, communication out of the cortex (into thalamus/spinal cord)
What is the function of the basal ganglia?
initiation of voluntary movement
What is the function of the hypothalamus?
visceral autonomic function, interfaces with endocrine system via pituitary gland
What is the general function of the thalamus?
Gateway to the cerebral cortex - relay station for vision, hearing & somatic sensation.
What is the corticospinal tract & it’s function
Cortical neurons axons, through the internal capsule to the brainstem & spinal cord to control voluntary movement
Where is the cerebral aqueduct & what is it a landmark for?
Connected the 3rd and 4th ventricles. It is a landmark for the midbrain
What are the tectum & tegmentum?
Tectum - tissue “roof” of cerebral aqueduct.
Tegmentum - tissue “floor” of cerebral aqueduct
collectively form the midbrain
What structures comprise the tectum & their functions?
- Superior colliculus - visual sensory input (controls reflex eye movement)
- Inferior colliculus - auditory sensory input
What is the function of the midbrain?
involved in sensory systems, motor control & other systems.
Axons pass through from cortex to brainstem/spinal cord
What structures comprise the tegmentum?
- substantia nigra & red nucleus - both motor centres
- modulatory neurotransmitter systems (consciousness, mood,
What structures comprise the tegmentum?
- substantia nigra & red nucleus - both motor centres
- modulatory neurotransmitter systems (consciousness, mood, pleasure, pain) - part of reticular formation
What is another name for the superior & inferior colliculi?
corpora quadrigemina
What structures does the rhombencephalon develop into?
- Cerebellum
- Pons
- Medulla Oblongata
What is pyramidal decussation?
motor information crossing the midline at the medullary pyramids
What is the 4th ventricle the landmark for?
The hindbrain (pons/cerebellum)
What structure does the caudal end of the neural tube develop into?
spinal cord
Identify the human brain ventricles
What makes human CNS unique?
- enormous cerebral cortex
- well developed temporal lobe - auditory processing
Identify the lobes of human cerebrum
What are common features of cerebral cortex in vertebrates?
- cell bodies in layers
- Surface later separated from pia mater
- apical dendrites form branches
What are the 3 types of cortex in all mammalian brains?
- hippocampus (archicortex - single layer)
- olfactory cortex (3 to 5 cell layers)
- neocortex (ie classic 6 layered)
What is the concept behind this diagram?
Map showing Brodmann’s areas - 52 distinct areas, identified histologically to have unique cytoarchitecture.
What is a connectome?
A detailed wiring diagram of connection
