Key structure of the Brain Flashcards
Describe the three main groups of nuclei of the thalamus
Sensory relays
Cerebellar and basal ganglia relays to motor frontal lobe
Connected to associative and limbic areas of cerebral cortex
Where is the thalamus located
Core of diencephalon
What is the role of the thalamus
Relays and integrates a myraid of motor and sensory impulses between the higher centres of the brain and peripheries
Are the thalamus white or grey mater
Grey mater - partitioned by a Y shaped white matter structure (internal medullary lamina)
What are the two protuberances on the posteroventral surface of the thalamus
Medial and lateral geniculate bodies
What is the role of the medial geniculate body
Processing auditory information
What is the role of the lateral geniculate body
Processing visceral sensory inputs
What is the thalamus covered by
Stratum zonale
What is the primary blood supply to the thalamus
Posterior cerebral artery
Describe the thalamus
Dorsal part of the diencephalon
Major subcortical relay for information ascending to the cerebral cortex
Afferent information may be modified by substantial descending projection to the thalamus from all parts of the cortex
Where does the hypothalamus sit
Within the medial wall of the third ventricle
What is the role of the hypothalamus
Principal visceral control centre of the brain
Mediates a broad range of functions via its connection with the endocrine, autonomic, somatic motor and limbic systems to remain a state of HOMEOSTASIS
What does the hypothalamus control
Body temp
Blood circulation
Food intake
Fluid and electrolyte balance
Sleep-wake cycle
Metabolism
Sexual behaviour
What are the main inputs to the hypothalamus
Circulating blood
Amygdala
Hippocampus
What are the main out puts of the hypothalamus
Pituitary - hormones - homeostasis
Where is the location of the hypothalamus
Behind the optic chiasm up to and including the mamillary bodies
Only part of the diencephalon visible on the outside of the brain
Describe the hypothalamus
Ventral part of the diencephalon that extends from the lamina terminalis in front to a vertical plane immediately behind the mamillary bodies
Important centre contributing to body homeostasis and to autonomic nervous system and neuroendocrine systems control
Describe the subthalamus
Ventral part of the diencephalon below the thalamus and lateral to the hypothalamus merging posteriorly with the tegmentum
Functionally closely associated with basal ganglia
What is the pituitary gland
Major gland of the endocrine system
What is the pituitary gland suspended by
Underside of the brain by pituitary stalk
Where in the bone does the pituitary gland sit
Small depression in the sphenoid bone - sella turnica
What are the two structures of the pituitary gland
Anterior lobe
Posterior lobe
Describe the anterior pituitary
Consists of glandular epithelium
Secretes a number of hormones
Controlled by the hypothalamus
Communicates via neurotransmitters secreted into the hypophyseal portal vessels
Describe the posterior pituitary
Consists of nervous tissue
Two hormones - ADH and oxytocin
Both substances are produced by the hypothalamus and stored in the posterior pituitary gland ready for release
What is the arterial supply to the anterior pituitary
Superior hypophyseal artery - branch of the internal carotid artery
Hypophyseal portal system - allows the thalamus to communicate with the anterior pituitary via the release of neurotransmitters into the blood stream
What is the arterial supply of the posterior pituitary
Superior hypophyseal artery
Infundibular artery
Inferior hypophyseal artery
