11. Thalamus and Hypothalamus

What does the diencephalon give rise to in brain development?

Thalamus and hypothalamus

What does the telencephalon give rise to?

Cerebrum

What was the main brain structure in fish and amphibians?

Diencephalon

What brain structure initially developed as olfactory centers?

Telencephalon

What is the role of the thalamus in the cerebrum?

Relay station for all sensory information except olfaction

What is the role of the hypothalamus in the brain?

Regulates hormones and homeostasis

How many thalami are there and what do they form?

Two; they form the walls of the third ventricle

What type of information synapses in the thalamus before reaching the cortex?

All sensations except olfaction

What does the ventral posterior lateral (VPL) nucleus relay?

Somatosensation from the body to the somatosensory cortex

What does the ventral posterior medial (VPM) nucleus relay?

Somatosensation from the face to the somatosensory cortex

What does the medial geniculate nucleus (MGN) relay?

Auditory input to the primary auditory cortex

What does the lateral geniculate nucleus (LGN) relay?

Visual input to the primary visual cortex

What does the ventral anterior (VA) and ventral lateral (VL) nuclei receive input from?

Basal ganglia and cerebellum for motor planning and coordination

What is the role of the pulvinar nucleus?

Integrates sensory information for the parietal lobe

What is the role of the anterior nucleus of the thalamus?

Basic emotional processing to the cingulate gyrus and medial frontal lobe

What is the role of the mediodorsal nucleus of the thalamus?

Risk-reward evaluation relayed to the prefrontal cortex

Where is the hypothalamus located in relation to the thalamus?

Inferior to the anterior thalamus

What type of structure is the hypothalamus?

Single midline structure composed of many nuclei

What are the three main functions of the hypothalamus?

Endocrine control, autonomic control, homeostatic regulation

What does the anterior pituitary receive from the hypothalamus?

Releasing and inhibiting hormones via the portal venous system

What hormones does the hypothalamus send to the posterior pituitary?

Oxytocin and vasopressin (ADH) via the hypophyseal tract

Which hypothalamic regions control parasympathetic functions?

Anterior and medial regions

Which hypothalamic regions control sympathetic functions?

Posterior and lateral regions

What are the two main brainstem tracts through which hypothalamic autonomic signals are relayed?

Dorsal longitudinal fasciculus (DLF) and hypothalamospinal tract

Damage to which tract can cause Horner syndrome?

Hypothalamospinal tract

Which part of the hypothalamus detects heat?

Anterior hypothalamus

Which part of the hypothalamus detects cold and triggers fever?

Posterior hypothalamus

Which nucleus suppresses appetite?

Ventromedial hypothalamic nucleus

Which nucleus promotes hunger and thirst?

Lateral hypothalamic nucleus

Which hypothalamic nucleus regulates circadian rhythm?

Suprachiasmatic nucleus (SCN)

Which hormone and structure are involved in circadian signaling to the SCN?

Melatonin from the pineal gland

What is the wake-promoting center of the hypothalamus?

Tuberomammillary nucleus (activated by orexin)

Deficiency in what neuropeptide leads to narcolepsy?

Orexin

What is the sleep-promoting area of the hypothalamus?

Preoptic area

What are the two components of emotion coordinated by the hypothalamus?

Affective tone and emotional expression

How does the hypothalamus connect the limbic system with autonomic and endocrine function?

Through the mammillary bodies and reciprocal connections with the amygdala and hippocampus