CNS- FA17- Hypothalamus Flashcards
Olfactory circuit
Dorsomedial nucleus of thalamus —> prefrontal cortex —> entorhinal —> amygdala —> hypothalamus & septal area
Papez circuit
Mammillary body —> anterior nucleus of thalamus —> cingulate gyrus —> Parahippocampla gyrus —> hippocampus—> fornix —> mammillary bodies
What are the jobs of the hypothalamus?
Involved in:
Endocrine system ANS Limbic system Olfactory system Behavior Maintains body’s internal environment Motivational behavior (looking for food)
The hypothalamus controls the body’s internal environment via which systems?
Endocrine
ANS
T/F: Most of hypothalamus is hidden under cerebrum
True
Border of the hypothalamus:
Superior
Hypothalamic sulcus
Hypothalamic sulcus divided what two structures?
Hypothalamus (superiorly) and thalamus (inferiorly)
Border of the hypothalamus:
Inferior (parts you can see)
Optic chiasm
Tuber cinereum
Mammillary body
Border of the hypothalamus:
Anterior
Lamina terminalis
Border of the hypothalamus:
Posterior
Midbrain tegmentum
Mammillary body
Border of the hypothalamus:
Medial
Third ventricle
Border of the hypothalamus:
Lateral
Fibers of internal capsule
Breaking up hypothalamus into nuclei and subnuclei:
Medial vs. Lateral
Divided by fornix
Breaking up hypothalamus into nuclei and subnuclei:
Lateral side
One nucleus= lateral nucleus
Breaking up hypothalamus into nuclei and subnuclei:
Medial side
3 areas
- Posterior/mammillary region
- Middle/tuberal area
- Anterior/supraoptic area
The posterior/mammillary portion of the medial side of hypothalamus has how many nucleus?
What are their names?
2 nuclei: Mammillary nucleus & posterior nucleus
The middle/tuberal area of the medial side of the hypothalamus has how many nuclei?
What are their names?
3 nuclei:
Arcuate/infundibulum
Ventromedial
Dorsomedial
The anterior/supraoptic area of this the medial part of the hypothalamus has how many nuclei?
What are their names?
4 Nuclei:
Supraoptic nucleus
Suprachiasmatic nucleus
Paraventricular nucleus
Anterior nucleus
Region of medial side of the hypothalamus that lies above and includes mammillary body?
Posterior
Region of medial side of the hypothalamus that is above and includes tuber cinereum
Tuberal area/ middle part
Part of medial hypothalamus that lies above the optic chiasm
Anterior/supraoptic area
Hypothalamus is involved with maintaining the body’s internal environment via endocrine and ANS.
What are the two types of neurons present?
Parvocellular
Magnocellular
Locations of parvocellular neurons
- Arcuate neurons
- Paraventricular neurons
- Many other areas
What are the hormones carried by parvocellular ?
- Releasing hormone
2. Inhibiting hormone
Job of inhibiting and releasing hormone from the parvocellular neurons?
Cause glandular tissue to release or inhibit the release of hormones
Where do the axons of the parvocellular end up ?
Infundibulum/median eminence/pituitary stalk
Where are the hormones from parvocellular neurons?
Capillary bed in in pituitary stalk
Where do the capillaries in the pituitary stalk flow?
To Anterior pituitary/ adenohypophysis
Anterior Pituitary can is (glandular/Nervous) tissue
Glandular tissue
Magnocellular neuron location
Supraoptic nucleus
Paraventricular
Where do the the magnocellular neuron axons travel?
Through infundibulum stalk into the POSTERIOR PITUITARY
Posterior pituitary AKA
Neurohypophosis
nervous tissue
Posterior pituitary is (glandular/Nervous tissue)
Nervous tissue
What is secreted from the magnocellular neurons?
Arginine vasopression
Oxytocin
Little beads along the length of the magnocellular neurons
Herring bodies
only called herring on magnocellular
What does the presence of herring bodies indicate?
Vesicles location
Function of vasopression AKA Antidiuretic hormone
Constrict blood vessel
Work with kidney to retain water
Vasopressin release is stimulated by
Low blood pressure (osmolality)or hemorrhage (decreased BP)
Function of oxytocin
Cause contraction of myoepithelial cells of mammillary glands-Milk ejection
Cause contraction of uterine smooth muscle
Other lesser function of oxytocin
Muscle spasm that occur with orgasm
Erection of penis and clitoris
Helps w/ vasopression-ADH properties
Digestive functions (digestive hormones can cause release i.e. stretching out th stomach after eating)
T/F: The Circum ventricular organs are not beyond the Blood Brain Barrier
False: beyond BBB
Throughout the brain the endothelial cells that align BV’s are (loosely/tightly) attached to BV’s to prevent bacterial infection
Tightly
6 areas outside BBB of circumventricular organs.
What are the two Dr. Mayne talks about
- Organum vasculosa of lamina termenalis-receptor that measures plasma osmolality (how much water in system)
- Area postrema- sensitive to digestive juices (stimulates this area and oxytocin can be released
Components of ANS
Preganglionic component
Ganglion
Postganglionic component
Effector
What drives the preganglionic component of the ANS
The hypothalamus
Anterior nucleus of autonomic center is associated with (parasympathetic/sympathetic) system
Parasympathetic
Posterior nucleus of autonomic center is associated with (parasympathetic/sympathetic) system.
Sympathetic
Temperature regulation is is controlled by the (anterior/posterior) nucleus of the autonomic system
Posterior nucleus
travels to lateral horn of SC to glandular tissue-causes you to sweat=lower tbody temp
Nucleus stuck between eh hypothalamus and midbrain responsible for motivational behavior for looking for water-drinking
Zona incerta
Nucleus of hypothalamus responsible for eating
Lateral nucleus-feeding
Ventromedial nucleus -Satiety
Nucleus of hypothalamus responsible for mood (rage/fear)
Lateral nucleus
Ventromedial nucleus
Nucleus of hypothalamus responsible for sleep/wake cycle
Suprachiasmatic nucleus- w/ pineal gland
Posterior nucleus (tuberomammilarry)-w/ histamine (keeps you active and aware)
Nucleus of hypothalamus responsible for memory and emotion
Mammillary bodies associated with papez‘ s circuit
Efferent pathway of hypothalamus that is a part of papez’s circuit
Mammilothalamic tract: Mammillary nuclei—> anterior nucleus of dorsal thalamus
Afferent pathway of hypothalamus that is a part of papez’s circuit
Fornix: from hippocampus —> anterior hypothalamus and septal area —> Mammillary nucleui
Reciprocal pathway of hypothalamus
- Medial forebrain bundle
2. Stria medullaris thalami
Reciprocal hypothalamus pathway that interconnects frontal lobes, basal forebrain, hypothalamus and midbrain
Medial forebrain bundle
Reciprocal hypothalamus pathway that interconnects supraoptic neclus, preoptic area, and septal area with the habenular nucleus(goes to brainstem)
Stria medullaris thalami
