The Nephron and Urine Formation!

Hey guys, sorry this wasn't up earlier! It was one of those situations where I don't look at my agenda until late Sunday night and then realize I forgot to write on the blog. SO, here it goes.

We learned a lot about the nephron this class. The nephron is the funcional unit of the kidney. As was said by Camille (I think it was Camille), nephrons are to the kidney as lobules are to the liver. There are approximately 1 million nephrons in the kidney and each are composed of a system of tubules. Each has its own blood supply. From the renal artery, the afferent arteriole leads into the glomerulus and then blood leaves the glomerulus by way of the efferent arteriole. The efferent arteriole then takes the blood to the peritubular capillaries which surround the rest of the nephron. The blood then goes to the renal vein.

Here is a diagram showing the path of the blood.

Next are the different parts of the nephron. First up is the GLOMERULAR CAPSULE, also known as Bowman's Capsule. Then we have the PROXIMAL CONVOLUTED TUBULE, which is difficult to remember so it can be shortened to PCT. Thirdly is the LOOP OF HENLE, which is a U-shaped tube composed of simple squamous epithelium. Next up is the DISTAL CONVOLUTED TUBULE, which again, may be difficult to remember. So we can shorten it to DCT. Last but not least are the COLLECTING DUCTS. They empty out into the renal pelvis.

Here is another lovely diagram, but this one shows all the different parts of the nephron that I just mentioned.

Now here is the big question that I know you are all secretly asking yourselves...

HOW IS PEE MADE? or in more formal terminoligy: URINE FORMATION.

You see, there are 3 steps to urine formation: GLOMERULAR FILTRATION, TUBULAR REABSORPTION, and TUBULAR SECRETION. Now I'm not going to go into great detail about these 3 steps because you can easily go read your powerpoint notes or textbook. Instead I'll show you a video:

*make note: she says capillary really weird (in my opinion)

AND, sorry guys! I couldn't figure out how to embed the video onto the blog.

http://www.youtube.com/watch?v=glu0dzK4dbU

Lastly, why is our pee yellow? Well, I actually coincidentally found out the answer to this question ON this blogger website. It said,

"The yellow color in urine is due to chemicals called urobilins. These are the breakdown products of the bile pigment bilirubin. Bilirubin is itself a breakdown product of the heme part of hemoglobin from worn-out red blood cells. Most bilirubin is partly broken down in the liver, stored in the gall bladder, broken down some more in the intestines, and excreted in the feces (its metabolites are what make feces brown), but some remains in the bloodstream to be extracted by the kidneys where, converted to urobilins, it gives urine that familiar yellow tint."

(http://sxxz.blogspot.com/2006/07/why-is-urine-yellow.html)

Read more...

ScribePost: Introduction of Urinary System (May 5)

Ok so today we started off with a pop quiz which was on the bolded words and the funtions of the urinary system found in 16.1 which is pages 304 to the top of 306

Functions of the Urinary System

- there are 4

Excretion of Metabolic Wastes
- this is the toxins leaving your body (nitrogenous wastes).
We started talking about survivorman and how you need to filter your pee before you can drink it if you ever happen to need to hydrate yourself and don't have water. For those of you not in physics who have not seen this video it's about a waterbottle which can filter out anything that is not smaller then 15 nm (nanometers). It's being used in third world countries so maybe an idea for St Mary's mission next year? Anyways here's the video if you want to check it out



Maitenance of Water-Salt Balance
-too much water = higher blood pressure = micturition

Maitenance of Acid-Base Balance
- excrete hydrogen ions but keep bicarbonate ions to make acid (which is why urine has a pH of 6 or lower)

Secretion of Hormones
-renin and erythropoetin

It was asked if high blood pressure caused a person to urinate more often so I researched it and there are no symptoms I could find on any medical website that said that urination occurred more often

Here is a diagram of the Urinary system similar to the one that's found in our textbook (page 305)

The 4 main organs are

1. Kidneys
2. Ureters
3. Urinary Bladder
4. Urethra

What I found most interesting in class was about the kidney stones. A kidney stone is a build up of iodine crystals which block the urethra causing you not to be able to pee and causes pressure on your bladder. You might remember a certain friends episode...

As Joey showed us it is very painful to pass kidney stones so I thought it would be good to get some prevention tips

Lastly we learnt about the actual urination.

1. stretch receptors in wall of bladder expand
2. it can hold up to 250 ml of urine
3. motor impulse from spinal cord causes contraction
4. micturition reflex occurs

The reflex is controlled more as we reach adulthood but as Mr Mac said with the dumbell analogy you can only hold your pee for so long.

The power point goes into more detail but as of late is not yet up on the downloads page so keep checking.

We're discussing the Nephron next class which FOR SURE is going to be on the exam either a long or short answer so make sure you pay attention next class. If you want a head start the reading of it starts on page 306 and its a couple pages of reading.

Read more...

Scribepost: April 23

So, on Friday we learned about the Thyroid Glands and talked about the Adrenal Glands.

-TSH is produced in response to hypothalamic releasing factor
>increase metabolic rate
>Stimulate all body cells
>More glucose is utilized to form ATP
>Necessary for normal growth and nervous system function

-Thyroid requires iodine to produce these hormones
>Iodine deficiency causes simple goiter

-Then we learned about the 3 different disorders that were related to the thyroid.
1. Cretinism

Abnormal thyroid development

-Short, stocky body type
-Severe hypothyroidism
-Mental retardation
-Treatment must begin in first 8 weeks of life

On the left is the scull of a person who was a cretin and on the right is the scull of a regular person.

(http://news.nationalgeographic.com/news/2004/10/photogalleries/homo_floresiensis_1/images/primary/flores_sapiens.jpg)



2. Myxedema

Hypothyroidism in adults

-lethargy
-weight gain
-loss of hair

On the left is what this man would look like with mxyedema and on the right is what the man would look like with average thyroid production.

(http://legacy.revoptom.com/handbook/images/62a.jpg)



3. Grave's Disease

Hyperthyroidism

-Exophthalmic goiter
-Edema behind eyes causes bulging
-Hyperactivity
-Arrythmias



(http://legacy.revoptom.com/handbook/images/62a.jpg)

Also this link is kind of cool and kind of gross if you guys want to check it out. http://www.youtube.com/watch?v=V4zh4jdd-m0

But anyways, linking this to real life. I was watching house on Monday, so yesterday night. They were talking about some kind of a disease that had to do with the adrenal glands, they went on to do a CAT scan, where they needed to look closely at the medulla oblongata. It was pretty cool that we actually learned about that stuff, and I sort of knew what they were talking about.

The power point is on the internet now, if you guys haven't downloaded it yet the link is http://www.mikemacaraeg.ca/09-10/Biology_11_Downloads.html.

Read more...

ScribePost: April 22 (20.1 &20.2) Endocrine system

Today in class we got an information overload, so here is a little review:

20.1 Endocrine Glands:

• Play very important role in homeostatis
• Produce hormones: These hormones are secrete directly into tissue fluid, then diffused into our blood stream

There are 2 control mechanisms to release hormones:

1. Negative feedback
2. Control by the presence of an atagonistic hormone *more important out of two*

Here are 2 videos that talk about the Endocrine System

1. http://kidshealth.org/kid/htbw/ESmovie.html (Funny)
2. http://videos.howstuffworks.com/hsw/5352-organ-systems-the-endocrine-system-video.htm

20.2 Hypothalamus and Pituitary Gland

Hypothalamus: Important homeostatic control center, it regulates water balence, hunger, body temperatur, hunger, and satiety. It also controls the Pituitary Gland

Pituitary Gland: Composed of 2 bodies

1. Anterior Pituitary- Secreates at least 6 different hormones- 3 out of 6 hormones have a target effect on other glands they are: TSH, ACTH, Gonadotrophic The other 3 do not have an effect on other glands they are: MSH, Growth hormone, and Prolactin
2. Posterior Pituitary- Stores ADH and Oxytocin, which are produced in hypothalamus

I hope this will help you in your 10 minute review tonight!

PS: The information in pink is important!!!!

Read more...

Pros/ Cons ans what i suggest

Acupuncture
Acupuncture is an old Chinese means of healing that has be used for thousands of years. Studies are always being done to prove the pros and cons of acupuncture. A pro for acupuncture is that no medication needs to be taken. This is good for people who do not want to constantly be popping pills. Also there are low risks of very harmful side effects. Also acupuncture is cost efficient. Instead of keeping up with constant prescription medications. It is also said to connect your mind, body , and spirit. Acupuncture can heal, nausea, and pain from arthritis. There are also some cons to acupuncture. If the needles are not sterilized infection can be caused. Also the person must be trained in acupuncture. Acupuncture may cause bruising and light bleeding. Also, those who blood diseases should maybe consider another treatment. Acupuncture does not cure arthritis but eases the pain temporarily.
I would prescribe acupuncture for certain people because it is a drug free, cost friendly , and effective way to temporarily relieve pain. It is a scary concept but it united your inner ying and yang. Acupuncture is not for everyone such as, those with heart disease however, it can help a variety of different pains. Acupuncture also relieves stress, and helps joint mobility. I know a couple of people who have gotten acupuncture and they said it was a bit scary at first but really helped them. My dad also suggests it quite a bit because he has gotten positive results from his patients from it. This concludes my opinion that acupuncture is a sufficient way to relieve pain temporarily.

Read more...

BONUS Blog: Acupuncture Case Study (3 points)

Since we are covering special senses right now, this post will deal with a case study that pertains to the sense of touch and cutaneous sense receptors.

You will be required to read the following Case Study, "A Need for Needles: Acupuncture - Does It Really Work?" by Sarah G. Stonefoot and Clyde Freeman Herreid. At the end of the document, you will find your task.

To receive the bonus blog points, you will need to put together an original comparison (2 points), as well as a follow-up conclusion/decision that describes your own opinion that is based upon your findings (1 point). Recommended length: 1 to 1.5 pages.

Read more...

ScribePost: April 7 (18.3 Sense of Taste and Smell)

Hi girls,

So we started class today reviewing the homework from last night.

Somatic sensors can be categorized into three types:

1. Proprioceptors - are involved in reflex actions that maintain muscle tone
2. Cutaneous - the skin is composed of 2 layers: the epidermis and the dermis. The epidermis is stratified squamous epithelium, and the dermis is a thick connective tissue layer. The dermis contains cutaneous receptors, which make the skin sensitive to touch, pressure, pain and temperature. The two different types of cutaneous receptors that are sensitive to pressure are Pacinian corpuscles and Ruffini endings.
3. Pain Receptors - the skin and many internal organs and tissues have pain receptors. Sometimes stimulation of internal pain receptors is felt as pain from the skin, and the internal organs, which is called referred pain.

We then moved onto learning about the sense of taste and smell (18.3)

Sense of Taste and Smell

• Taste cells and olfactory cells (smell) are both chemoreceptors

Sense of Taste

• The sensory receptors in your mouth are called taste buds
• There are approximately 10 000 taste buds on a human tongue
• Each papillae (the small elevations on the tongue) has many taste buds on it
• There are four primary types of taste: sweet, salty, sour and bitter *THIS IS VERY LIKELY TO BE ON THE EXAM*
• MSG (monosodium glutamate) is a flavour enhancer found most frequently in Chinese food. Some people have an intolerance to it, which makes their taste bud activators really sensitive at first and then really insensitive so that they can't taste much. As Mr. Macaraeg would say the taste it like "wow wow wow and then nothing"

Sense of Smell

• Smell receptors in your nose are called olfactory receptors
• About 80-90% of what we "taste" actually comes from smell, which explains why when we're sick food tastes more dull than usual
• Olfactory cells are modified neurons, and each cell ends in a tuft of 5 cilia.
• Odor = aroma = smell

Here are some links to videos that deal with what we learned today:

How smell and taste are related

Sense of Taste

Read more...