CBNS116 Hypothalamus and Pituitary

What are the 3 controls of the hypothalamus?

somatic, humoral, visceromotor

• voluntary motor → muscle contractions

• hormonal response

• autonomic motor

What are the key hypothalamic nuclei?

Pr, SON, SCN, Ar, PVN, MB

What is the job of the Preoptic Region (PR)?

Sleep promoting and body temp regulation

What is the job of the Supraoptic Nucleus (SON)?

ADH and Oxytocin release

What is the job of the Suprachiasmatic Nucleus (SCN)?

Sends light info to the pineal gland for circadian rhythm

What is the job of the Arcuate Nucleus (AR)?

Controls feeding behavior and reads/sends out blood hormone info

What is the job of the Paraventricular Nucleus (PVN)?

Releases hormones to the pituitary gland

What is the job of the Mammillary Bodies (MB)?

Autonomic emotional responses

Is the anterior pituitary apart of the CNS or not?

Not apart of the CNS

Is the posterior pituitary apart of the CNS or not?

Apart of the CNS

What are the major inputs into the hypothalamus?

• Dorsal Longitudinal Fasiculus (DLF) → input from the spinal cord and brainstem

• Stria Terminalis (ST) → input from the amygdala

• Ventral Amygdalofugal Pathway (VAP) → input from the amygdala

What are the major outputs from the hypothalamus?

• SON → anterior pituitary

• PVN → posterior pituitary

• MB → anterior nucleus & brainstem

• DLF → brainstem and spinal cord

• ST and VAP → to amygdala

What are the 2 primary subsystems of the limbic system?

Amygdala and Hippocampus

What does the amygdala do?

Processes emotions

What does the hippocampus do?

Leaning and memory

Where is the amygdala located in the limbic lobe?

Anterior

Where is the hippocampus located in the limbic lobe?

Posterior

What are the 3 amygdala nuclei?

Medial, Central, and Basolateral

What does the central nuclei connect the amygdala to?

Connects the amygdala to the Hypothalamus

What does the basolateral nuclei connect the amygdala to?

Connects the amygdala to the Neocortex

What does the medial nuclei connect the amygdala to?

Connects Olfaction to the amygdala

Step 1 of the reward pathway

Input from the Limbic Cortex, Amygdala, Hippocampus → Ventral Striatum (VS) A.K.A Nucleus Accumbens

Input from the Ventral Tegmental Area (VTA) → Sends dopamine to the Nucleus Accumbens

Step 2 of the reward pathway

Nucleus Accumbens sends perceived information to the Ventral Pallidum (VP) → VP says “Hey I like that” → Sends info to the Thalamus

Step 3 of the reward pathway

Thalamus perceives message from VP → Relays message to the Limbic Cortex to make note that whatever action just happened leads to happiness. This connection keeps you wanting to do it more to release more dopamine.

What does having more dopamine receptors lead to?

Addiction because overdoing the release of dopamine triggers more receptors needed to achieve the same feeling.

What path does the Central nuclei lead to?

Central (Autonomic) Pathway → Fight or Flight

What path does the Medial nuclei lead to?

Olfaction

What path does the Basolateral nuclei lead to?

Neocortex → Dopamine

What is fear affect?

Outward expression of emotion, especially on muscles of facial expression