Oxytocin
If there is no cephalopelvic disproportion, correct hydration and augment with oxytocin.
Oxytocin
- Synthesis Location: Primarily synthesized in the paraventricular nucleus of the hypothalamus.
- Function: Stimulates uterine contractions during labor and promotes milk ejection (milk let-down reflex) during lactation. It also plays a role in social bonding, trust, and maternal behavior.
- Regulation: Released in response to cervical stretching during labor (Ferguson reflex) and suckling during breastfeeding. It operates via a positive feedback loop.
- Clinical Relevance: Synthetic oxytocin (Pitocin) is used to induce or augment labor and to prevent postpartum hemorrhage. Its role in social behavior is an active area of research.
- Positive Feedback Loop during Parturition: During labor, uterine contractions push the baby's head against the cervix, stretching it. This stretching sends nerve impulses to the hypothalamus, which signals the posterior pituitary to release
Read this in Hypothalamic Hormones: Master Regulators of the Endocrine System
What our notes say
- If there is no cephalopelvic disproportion, correct hydration and augment with oxytocin. (Reproductive Health End of Trimester 2 CAT (MBOG 4223): labour and cord prolapse)
- Oxytocin 10 IU IM within one minute of birth is the key step (the paper says 10 minutes). (Junior Clerkship in Reproductive Health (MBOG 4200): end of year examination, 4 )
- | Neuropeptides | Modulate other transmitters (for example endorphins, oxytocin, substance P) | Involved in pain, stress and social behaviour. | (Introduction to Psychopharmacology)
- Record oxytocin and drugs (none), and the time every 30 minutes for FHR and contractions and every 4 hours for the cervix. (Reproductive Health End of Trimester 2 CAT (MBOG 4223): labour and cord prolapse)
- Administration of 10 IU oxytocin IM on the anterior thigh within 10 minutes of delivery of the baby (Junior Clerkship in Reproductive Health (MBOG 4200): end of year examination, 4 )
- At term, induce labour (oxytocin or prostaglandin) within about 24 hours, as the risk of infection rises with time. (Integrated case paper: Medicine, Surgery, Gynaecology and Paediatrics (160 marks)
Study material on Oxytocin
- Endocrine and Metabolic Pathology MCQs: Practice Questions
- Endocrine and Metabolic Pathology MCQs for Medical Students
- Hypothalamic Hormones: Master Regulators of the Endocrine System
- Endocrine and Metabolic Pathology MCQs
- Medical Physiology Year Two – Paper Two MCQs
- Paediatrics main exam (MBPE 4300): 24 January 2022, Paper One, 100 MCQs, 2 short essays and 2 long essays
- LECTURE 1: Principles of Endocrinology
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Practice questions on Oxytocin
Which statement is true regarding oxytocin? ---
- Essential for milk ejection
- Increases uterine contractility
- Facilitates sperm transport in the uterus
- All of the above
- Usually mediated by non-specific mechanisms
Answer: D.