Bài giảng Thần Kinh tại PTCU

From: TMMCDN.THUANTV 

Date: Thu, Jun 11, 2020 at 11:02 PM

Subject: RE: Hỏi thăm sức khỏe

To: Bùi Duy Tâm <buiduytam1@gmail.com>

Dạ hay quá Thầy.

Hôm trước mấy buổi thầy dạy online sinh viên em có tham gia đó. Lúc đó có thầy Tùng và thầy Vân tham gia nữa.

Thời gian tới em sẽ sắp xếp tham gia nhiều hơn.

Chúc thầy và gia đình sức khỏe.

Trân trọng

Tô Viết Thuấn

Dr.TO VIET THUAN

Medical doctor. PhD.

Head of Internal Medicine Dept.

Phan Chau Trinh University

From: Bùi Duy Tâm [mailto:buiduytam1@gmail.com]
Sent: Thứ Sáu, Tháng Sáu 12, 2020 11:22 AM
To: TMMCDN.THUANTV
Subject: Hỏi thăm sức khỏe

 Cám ơn anh Thuấn. Tôi vẫn khỏe để tiếp tục dạy CME bằng cách gửi JAMA & AAFP cho các bác sĩ PCTU & BVTT và vẫn tiếp tục giảng dậy cho sinh viên qua Cisco Webex. Bây giờ đương ôn bài cho sinh viên sửa soạn thi Final. Tư liệu học tập viết công phu lắm. Thày Sĩ và cô Hạnh (thư viện) có lưu trữ để dùng hằng năm. Rất tiếc BS.Thuấn, BS. Giang, BS. Linh không cộng tác với tôi trong việc đó (mutual benefits cho cả Thày và Trò), vừa thâm cứu Y Học vừa áp dụng Lâm Sàng. Thày Tùng và Thày Vân thường tham dự các buổi học tập của sinh viên. Vui lắm! 

Anh Thuấn ạ, phải nên vừa Hành (khám bệnh) vừa Học mới  tiến bộ về Học và cải tiến về Hành (khám bệnh).

Tâm

Đây là một vài câu hỏi & trả lời Q/A tôi soạn cho sinh viên để sửa soạn thi final:

Q.53: giải nghĩa adrenaline và adrenergic receptors?

A: adrenaline đến các target sẽ có tác dụng khác nhau vì mỗi target có một receptor khác. Adrenaline có nhiều receptors:alpha (alpha1 & alpha2) & beta (beta1, beta2, beta3).

The adrenergic receptors or adrenoceptors are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta blockers, β2 agonists and α2 agonists, which are used to treat high blood pressure and asthma, for example.

Many cells have these receptors, and the binding of a catecholamine to the receptor will generally stimulate the sympathetic nervous system (SNS). The SNS is responsible for the fight-or-flight response, which is triggered by experiences such as exercise or fear-causing situations. This response dilates pupils, increases heart rate, mobilizes energy, and diverts blood flow from non-essential organs to skeletal muscle. These effects together tend to increase physical performance momentarily.

There are two main groups of adrenoreceptors, α and β:

·         α are divided to α1 and α2 

·         β are divided to β1, β2 and β3 

Q.62: Norepinephrine and epinephrine are both used in emergency medicine but what is the difference between them?

A:

·  Although norepinephrine and epinephrine are structurally related, they have differing effects. Noradrenaline has a more specific action working mainly on alpha receptors to increase and maintain blood pressure whereas epinephrine has more wide-ranging effects. Norepinephrine is continuously released into circulation at low levels while epinephrine is only released during times of stress.

Norepinephrine Vs epinephrine: Synthesis and Actions in the body

Naturally occurring norepinephrine is mostly made inside nerve axons (the shaft of the nerve), stored inside vesicles (small fluid-filled sacs), then released when an action potential (an electrical impulse) travels down the nerve. Noradrenaline travels across the gap between two nerves where it binds to a receptor on the second nerve and stimulates that nerve to respond. This is norepinephrine acting as a neurotransmitter. Norepinephrine causes vasoconstriction (a narrowing of the blood vessels) so is useful for maintaining blood pressure and increasing it in times of acute stress.

Norepinephrine is also made in the adrenal medulla where it synthesized from dopamine and is released into the blood as a hormone.

Epinephrine is made from norepinephrine inside the adrenal medulla (the inner part of the adrenal gland, a small gland associated with the kidneys). Our adrenal medulla helps us to cope with physical and emotional stress. The synthesis of epinephrine increases during times of stress. Epinephrine acts on almost all body tissues, but its effects are different depending on the tissue, for example, epinephrine relaxes the breathing tubes, allowing easier breathing, but contracts the blood vessels (keeping blood pressure up and ensuring brain and heart are perfused with blood). Epinephrine also increases the heart rate and force of contraction, blood flow to the muscles and brain and aids the conversion of glycogen (a stored form of energy) into glucose in the liver. 

Epinephrine diffuses through the adrenal medulla into the blood which perfuses the adrenal glands and is then carried throughout the body.

Norepinephrine Vs epinephrine: Epinephrine has a wider range of effects

Norepinephrine acts mostly on alpha receptors, although it does stimulate beta receptors to a certain degree. One of its most important roles is to increase the rate of contractions of the heart, and together with epinephrine, it underlies the fight-or-flight response.

Epinephrine is relatively nonspecific, stimulating both alpha, beta 1, beta 2, and beta 3 receptors more or less equally. By binding to these receptors epinephrine triggers a number of changes, all of which are aimed at either increasing energy use by the body or making more energy available to be used, for example:

o    Alpha receptors: Insulin secretion by pancreas, glycogen breakdown in the liver and muscle, glycolysis (convert glucose into pyruvate)

o    Beta receptors: Glucagon secretion by the pancreas, increased ACTH secretion by the pituitary gland, increased fat breakdown by adipose tissue.

Norepinephrine Vs epinephrine: Use in medicine

In medicine, norepinephrine is used to increase and maintain blood pressure in acute situations where low blood pressure is a feature (such as cardiac arrest, spinal anesthesia, septicemia, blood transfusions, drug reactions). It is usually used in addition to other agents.

Epinephrine is used in medicine to treat low blood pressure associated with septic shock, for the emergency treatment of allergic reactions, and in eye surgery to maintain dilation of the pupil. It is also available in an autoinjector for people with a history of severe allergic reactions.

Bottom-line

In medicine, norepinephrine is used to increase or maintain blood pressure during acute medical situations that cause low blood pressure and 

epinephrine is used in the emergency treatment of allergic reactions, to treat low blood pressure during septic shock, and in eye surgery to maintain dilation of the pupil.

  Q.70:  Điền tên vào đầu đường chỉ và giải thích sơ đồ?  

  Q.73:  Điền tên vào đầu đường chỉ và giải thích sơ đồ?