Week 3 Lecture 8: The forebrain Flashcards
What is the cerebrum/ forebrain composed of?
Two parts:
- telencephalon (outer brain)
- inner brain (diencephalon)
During embryonic development, what structure connects the two swellings that grow to be the cerebral hemispheres? What does this structure become in the adult brain?
- developing telencephalon is connected via lamina terminalis
- lamina terminalis goes on to become the corpus callosum and anterior commissure
What is the anterior commissure?
white matter tract connecting two temporal lobes of the central hemispheres across the midline
What two swellings appear as the diencephalon develops and what divides the two swellings?
- thalamus, dorsally and hypothalamus, ventrally
- hypothalamic sulcus forms the division between the thalamus and hypothalamus
What is the function of the ventricular system of the brain?
production, transport and removal of cerebrospinal fluid
Where is CSF produced?
choroid plexus
How is the lateral ventricle connected to the third ventricle?
interventricular foramina (of Monroe)
What connects the 3rd and 4th ventricle?
cerebral squeduct
Which lobe are each of these structures in the lateral ventricle found in:
- anterior horn
- inferior horn
- body
- posterior horn
- frontal lobe
- temporal lobe
- parietal lobe
- occipital lobe
What is the 3rd ventricle found between?
right and left thalami
What are the four divisions of the diencephalon?
- thalamus: relay station between parts of the CNS
- hypothalamus: autonomic and neuroendocrine functions
- subthalamus: functionally part of basal ganglia and involved in motor control
- epithalamus
Where is the pineal gland found and what does it secrete?
- found in the epithalamus
- secretes melatonin
What are thalami?
large bi lateral egg shaped masses of grey matter (collection of nuclei)
How can the two thalami communicate?
they are connected at the interthalamic adhesion (massa intermedia)
What is the function of the thalamus?
- “receptionist” of the brain - information is sent to the thalamus and the thalamus decides where to next send it
- relay nuclei send fibres to cerebral cortex
- sensory processing (except olfaction)
- motor processing through connections with the basal nuclei (ganglia) and cerebellum
Which structures/ systems send information to the thalamus?
- basal ganglia
- cerebellum
- somatosensory, auditory, visual, vestibular and other inputs
- reticular formation
- limbic system
What is the function of the limbic system?
functional lobe that deals with emotion and memory
How is the thalamus divided into 3 main areas?
- anterior nuclear group
- medial nuclear group
- lateral nuclear group
Where does the anterior nuclear group send information to?
cingulate cortex (part of limbic system)
Where does the medial nuclear group send information to?
prefrontal cortex (cerebral cortex covering the frontal lobe)
In the lateral nuclear group, there are further nucleic divisions.
Where do the following key nuclei send their information to?
1. Ventral posterior lateral
2. Ventral posterior medial
3. Lateral geniculate
4. Medial geniculate
- somatosensory cortex
- somatosensory cortex
- visual cortex
- auditory cortex
What is the hypothalamus involved in?
homeostasis and autonomic control e.g sexual response, body temperature and blood pressure
What is the corpus striatum?
- internal structure of grey matter (nuclei) of each cerebral hemisphere
- part of the basal nuclei (basal ganglia)
- involved in motor control
What 3 structures is the corpus striatum composed of?
- global pallidus (internal and external)
- putamen
- caudate nucleus
