L3 - Environmental Influences

Question 1

How is the link between the nervous and endocrine systems implemented?

Answer 1

• The Hypothalamic-Pituitary Axis (Central regulatory component of endocrine system)

Question 2

The Pituitary Gland (4)

Answer 2

• Master endocrine gland”
• Anterior and posterior lobes:
• Respond to, and produce, different hormonal products
• Have no direct functional interaction with each other

Question 3

The Hypothalamus (nuclei, function, name of large neurones, tract, 2 hormones produced)

Answer 3

• Supraoptic and paraventricular nuclei (remember their location)
• Posterior pituitary function
• Magnocellular (large) neurons in anterior hypothalamus
• Supraoptic-hypothalamic tract
• Oxytocin
• Antidiuretic hormone (ADH, or vasopressin)
• Storage granules in posterior pituitary

Question 4

How does the hypothalamus communicate with the anterior pituitary gland?

Answer 4

• Hypothalamic-hypophyseotropic nuclei

Parvocellular neutrons (in hypo) receive signals from the brain using NT - release hormones to primary plexus - releasing hormones through here to secondary plexus (through fenestrations) - they wraparound APG - releasing other hormones from here

Question 5

THR roles 2

Answer 5

1. Releasing hormone - Pituitary TSH release

2. Other regions of he brain - regulation of appetite and mood

Question 6

Other hypothalamic hormones: Orexins

Answer 6

• Orexin A and B (also known as hypocretins)
• Neuropeptide hormones
• Released from cells in lateral and posterior hypothalamus
• Promote wakefulness and eating
• Secretion inhibited by glucose and leptin
• Narcolepsy

Question 7

Separation of the infundibular stalk (what it leads to)

Answer 7

• The infundibular stalk between hypothalamus and pituitary was clamped, or separated (reduced/stopped blood supplied) = Blood supply from H to P was therefore reduced or prevented
• Red boom is what the experiment causes (stops communication)
• Weight gain
• Dystrophia adiposo-genitalis
• Genital and mammary atrophy
• Anterior pituitary atrophy

Question 8

Clinical Case Study (Features 6, secondary to, treatment, role of optic nerve)

Answer 8

Obesity
Failure to enter puberty
Small testes
Headaches
Visual abnormalities
Froelich’s disease (dystrophia adiposo-genitalis)

Secondary to craniopharyngioma compressing pituitary gland or hypothalamus

Treatment via removal of tumour

Tumor on PG presses on optic nerve and causes visual impairment