Just like 'old times'

Even though I was taking a day off today*, I got up at 5:30 am and took the dog for her early morning walk. By about 6 am, she had done what she had needed to do, and we were about a third of the way through our walk. At this stage, my phone started emitting a sound that I couldn't place at first: I took it out of my pocket and saw that the home guard were dispaying a warning message about an imminent air raid warning. So I immediately turned and we started walking back home at an increased pace, not stopping for any sniffing around. At about a distance of 100 metres from my home, the air raid warning starting sounding - it's quite frightening to hear it when outside. People from the building neighbouring ours were coming down the stairs and heading for the nearest air raid shelter whereas the dog and I were half running home in order to get to our secure room. There are only a few buildings on my side of the kibbutz that have a secure room so we are quite privileged in this respect.

After the all clear signal had been given (via telephone), we were free to exit the room. I had intended to go swimming this morning at 7 am, and I saw no reason not to go. If the pool was closed then all I would have done was complete my early morning walk. By 7 am, I was at the pool and saw the life guard open up; there was only me and another swimmer there. At that hour, the air temperature is much closer to the water temperature, so the cold water didn't bother me. After swimming a few lengths, I thought that I heard an odd sound, so I treaded water for a bit, then carried on. A few minutes later, the air raid sirens sounded again.

So it was out of the pool and into an air raid shelter that was conveniently close to the pool. When I went down into the main room, I was surprised how many people were there; presumably the odd sound that I had heard before was the early warning. A few people made some comments about my attire, but I wasn't paying attention so I didn't realise that they were talking about me. After about 20 minutes, the all clear sounded and we all exited the shelter. By this time, I had lost interest in swimming, but I had to go back to the pool to pick up my headphones, cap and robe; the other person who had been swimming with me was back in the water.

On the way back home (I live on the opposite side of the kibbutz from the pool), three or four people stopped me and asked if the pool was open. I repeated my story. Later on, a message appeared on the electronic notice pool that all pools in our general area would be closed for the rest of the day.

So it's just like 'old times' of the earlier wars with Iran and Yemen from the past year.

* A few weeks ago, I noticed that I had accumulated many days of holiday. As I will soon be retiring, these days would be turned into money and as a result I would be paying a great deal of income tax for this extra payment. I also receive two days holiday a month, so if I did nothing, I would end up with 36 days of holiday. As a result, I've been taking one day of holiday each week.

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This day in blog history:

Blog #	Date	Title	Tags
82	08/06/2007	Rise up like the sun	Fairport Convention, Albion Band, Time signatures
591	08/06/2013	Barcelona log (3): Rain stopped play	Holiday, Barcelona
1041	08/06/2017	Rodos log 4: Lindos and the seven springs	Holiday, Rodos, Greece
1143	08/06/2018	Italy 2018 - The best chocolate in the world	Holiday, Peppermint, Torino, Italy
1144	08/06/2018	Italy 2018 - Getting to know Torino	Holiday, Torino, Italy
1323	08/06/2020	The background behind another song that is used for Israeli folk dancing	Kibbutz
1395	08/06/2021	A new Yoni Rechter songbook	Yoni Rechter
1511	08/06/2022	Italy 2022: Corso Cavour (2)	Holiday, Italy, Bari
1627	08/06/2023	Post doctorate	Nutrition
1948	08/06/2025	Diet, drugs and dopamine	Non-fiction books, Nutrition

Why zebras don't get ulcers

Over the past week, I've been reading this very interesting (for me) book. In order not to misrepresent the author, I'm going to quote some paragraphs from the opening chapter.

For animals like zebras, the most upsetting things in life are acute physical crises. You are that zebra, a lion has just leapt out and ripped your stomach open, you’ve managed to get away, and now you have to spend the next hour evading the lion as it continues to stalk you. Or, perhaps just as stressfully, you are that lion, half-starved, and you had better be able to sprint across the savanna at top speed and grab something to eat or you won’t survive. These are extremely stressful events, and they demand immediate physiological adaptations if you are going to live. Your body’s responses are brilliantly adapted for handling this sort of emergency.

The half of the autonomic nervous system that is turned on is called the sympathetic nervous system. Originating in the brain, sympathetic projections exit your spine and branch out to nearly every organ, every blood vessel, and every sweat gland in your body. They even project to the scads of tiny little muscles attached to hairs on your body. If you are truly terrified by something and activate those projections, your hair stands on end; gooseflesh results when the parts of your body are activated where those muscles exist but lack hairs attached to them. The sympathetic nervous system kicks into action during emergencies, or what you think are emergencies. It helps mediate vigilance, arousal, activation, mobilization. To generations of first-year medical students, it is described through the obligatory lame joke about the sympathetic nervous system mediating the four F’s of behavior—flight, fight, fright, and sex. It is the archetypal system that is turned on at times when life gets exciting or alarming, such as during stress. The nerve endings of this system release adrenaline. When someone jumps out from behind a door and startles you, it’s your sympathetic nervous system releasing adrenaline that causes your stomach to clutch.

The other half of the autonomic nervous system plays an opposing role. This parasympathetic component mediates calm, vegetative activities—everything but the four F’s. Sprint for your life across the savanna, gasping and trying to control the panic, and you’ve turned the parasympathetic component down. Thus, the autonomic system works in opposition: sympathetic and parasympathetic projections from the brain course their way out to a particular organ where, when activated, they bring about opposite results. The sympathetic system speeds up the heart; the parasympathetic system slows it down.

Another important class of hormones in the response to stress are called glucocorticoids. 

The body synthesizes these glucocorticoids, but we can also be given synthetic glucocorticoids, a good example being Prednisone that is a potent synthetic corticosteroid used to quickly reduce inflammation, suppress an overactive immune system, or replace natural cortisol. It is prescribed for a wide variety of conditions, including severe allergies, asthma, arthritis, and autoimmune diseases like lupus. 

The neurologist¹gave me a referral for a head CT, using a contrast dye. In Israel (and probably elsewhere), someone who has a bad reaction to such dyes is considered to be allergic to Iodine, although this is not accurate as iodine is a required micronutient for the thyroid gland. Reactions to intravenous X-ray/CT contrast media are typically caused by the physical properties (e.g., hyperosmolarity) of the solution itself, not the iodine it contains. I am not sure whether I am 'allergic to Iodine'; it is written in my medical history and so everyone has to be careful. I underwent a procedure some 40 years ago to do with my kidneys and had a bad reaction to the 'iodine' although whether that is considered to be severe enough to be an allergy is uncertain. I have an appointment with an allergy doctor in August to settle this once and forever.

The connection between this scan (which was done yesterday) and the glucocorticoids is that I had to undergo a 'preparation protocol' that involved taking prednisone three times at various hours of the day along with another medicine an hour before the test. Everyone at the hospital checked that I had taken the medicines although obviously they had to rely on my answer. 

I am going to go into detail about what I felt from the scan onwards, primarily so that I will have it documented. During the test itself, the only abnormal thing that I felt was as if part of my testicles had been lowered into warm water; the rest of the body felt fine. My hands were shaking slightly but that's something that I've noticed over the past few weeks. After I got home, I took the dog for a walk then had a light supper. I felt slightly warm but I thought that this was due to walking the dog. By the time I came to measure my blood pressure at 9 pm, I was surprised to see that it was high (relatively for me) at 125/82 with a pulse of 102. For comparison, the readings on Sunday evening were 103/78 and pulse 77. When I got into bed, I felt quite warm, despite the air conditioner, and slept for some time uncovered.

Obviously the prednisone had activated the sympathetic nervous system, and the iodine was having its effect.

Going back to zebras and why they don't have ulcers: humans have both external sources of stress and internal souces, or psychological stresses. Unfortunately, the body can't distinguish between the two sources and so the sympathetic nervous system gets unnecessarily mobilised, moving blood to our arms and legs and taking it away from other areas of the body. One familiar source of psychological stress is how much control we feel we have over our lives, otherwise known as locus of control. Those with a low locus of control have more stress than those with a high locus. 

My job affords me with a very high locus of control, but I remember that when I was in the army (compulsory service and reserve duty) I had a very low locus, and I used to say that if something were about to happen and I could think of two alternatives, the army would always choose a third option which would be worse than anything that I could think of. 

Internal links
[1] 2095

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This day in blog history:

Blog #	Date	Title	Tags
952	03/06/2016	Dave Swarbrick, RIP	Obituary, Fairport Convention
1505	03/06/2022	Italy 2022: pre-flight check	Holiday, Italy, Bari
1771	03/06/2024	Cruise log #2: Rodos	Holiday, Rodos, Greece
1943	03/06/2025	A cheap source of Erythritol	Erythritol