The Urinary System

The urinary system has many functions including the following: regulation of glucose levels, blood volume, blood pressure and pH. Also produces hormones and excretion of waste and foreign substances. The kidneys do a major part of the work in the urinary system. The blood flow of the kidneys starts at the renal arteries. From there the renal artery divides into several segmental arteries. Then the segmental arteries goes into the interlobar arteries and then to the arcualte arteries. These arteries divide and make interlobular arteries. These arteries enter the renal cortex and branch into afferent arterioles.

The kidneys are important and we have are lucky to have two of them. We can live with one if we have to. A kidney transplant is one of the few organs that can be taken from a live donner. This is incredible to be able to help someone else and still live to do it.

The Digestive System

The digestive system starts with the gastrointestinal tract, also called the alimentary canal. This canal starts at the mouth and ends at the anus. The functions of the digestive system are: ingestion, secretion, mixing, digestion, absorption, and defecation. There are four layers of the alimentary canal. The first later is the mucosa layer that is made of simple c. epithelium. This layer is avascular and the cells in this area are constantly being replaced. The second layer is the submucosa layer. This layer is highly vascular and is made of dense irregular connective tissue. The third layer is the muscularis. This layer consist of the circular and longitual layers. This is made of smooth muscle. The last layer is serosa which is made of areolar connective tissue and is also highly vascular.

Most of us eat on a daily basis and the digestive system is working all the time. Could you imagine having Achalasia? Your probably thinking what in the world is that. Achalasia is a muscular disorder in the esophagus. This disorder makes it very difficult to swallow and sometimes your food does not even reach your stomach. I am thankful that I do not have this. It would make it very difficult to eat.

Blood And The Heart

Last time we talked about the importance of blood and the process of blood clotting. Now we are going to take a look at blood flow through the heart. This includes two pathways: the pulmonary circuit and the systemic circuit. The pulmonary circuit circulates blood through the heart and into the lungs. The systemic circuit circulates blood through the heart only. The pulmonary circuit starts at eh right atrium, goes through the tricuspid valve, and into the right ventricle. From here the blood goes through the pulmonary semilunar valve and through the pulmonary trunk into the right and left pulmonary arteries. Then the blood reaches the lungs. They systemic circuit starts in the left atrium, goes through the bicuspid valve, and into the left ventricle. From there the blood goes through the aortic semilunar valve and into the aorta.

The blood flow to the heart is an important subject for me to understand because of my mother. Just recently she was in the hospital because the blood was pumping faster in the atrium then in the ventricle. This gave her a "flutter" in her chest, also known as atrial fibrillation.

Blood

Blood is one of the easiest parts of the body to donate. Blood transports oxygen, carbon dioxide, nutrients, and waste through the body. Blood also regulates your body temperature and is important in blood clotting. The process of blood clotting is also called hemostasis. This starts with vasocontriction of the damaged blood vessels. Then the platelets form a "plug" over the wound. This is activated by fibrin prothrombinase. This changes into thronbin which forms the blood clot.

This blood clotting process is important to all of us. If anyone loses too much blood, they can eventually die. If you have ever had a large cut, you know the blood will clot and dry up. This is what is supposed to happen. Without this process we would lose to much blood.

Week 9

There are four blood types: A, B, AB, and type O. Type A blood has A antigens on the surface of the red blood cells and has an anti-B antibody in the plasma. Type B blood is just the opposite with B-antigens on the surface and anti-A antibody in the plasma. Type AB blood has both A and B antigens on the surface and no antibodies in the plasma. Type O blood has no antigens but have both anti A and anti B antibodies. There are also Rh antigens, if someone has these they are Rh positive and if they do not they are Rh-. Knowing these blood types are important for donating and receiving blood.

A women who is Rh negative and is with a male who is Rh positive and is thinking about a child, they want to take precautions. During birth the blood will mix from the baby and the mother, this will cause the mother to develop Rh antibodies. If she does not have a Rhogan shot within 48 hours after the first child, she will develop these antibodies. When she is pregnant with the second child, this will cause clumping of the blood cells and the newborn will be oxygen deprived. This is know as hemolytic disease of the newborn.

Week 8

This week we learned about the second messenger system and its two pathways. There is the cAMP pathway and the PKC pathway. These pathways are much easier to understand through diagrams instead of words. We also went over protein and steroid hormones. There are many differences between the two. The role of the steroid hormone is to make new protein hormones where as the protein hormone causes the hormones to deactivate and activate their activities. Steroid hormones when traveling through the blood have to be connected with a transport protein. This is the case because a steroid hormone is non-polar. This process takes longer than a protein hormone but has a longer half-life. Protein hormones travel through blood. Protein hormones might travel faster but they also have a shorter half-life and degrade fast.

There is a disorder know as the hypersecretion disorder. This is when there is more of a hormone being secreted than necessary in the gland. This is caused by the tropic hormone. There is also hyposecretion where not enough hormone is being produced to function properly. These disorders can be caused by genetics, our diets, or infections. So take care of your body and eat healthy.

Week 7

This week we started to learn about the endocrine system. What an interesting topic to go over. It effects our bodies in many ways. Adrenocorticotropic hormone (ACTH) is produced in the anterior pituitary, by the adrenal cortex. The function on ACTH is to regulate cortizine levels in your body. Antidiuretic hormione (ADH) is produced in the hypothalamus, by the kidney tubules. ADH retains urine and lowers the frequency volume so you stay hydrated. Some other hormones include thyroxine, aldosterone and growth hormones. We also went over steroidal hormones and how they get into the blood. Next week we will go more in depth on this.

Have you ever had any type of shot involving cortizone? This will regulate your levels if you are not producing enough on your own. Have you heard the saying " too much of a good thing is actually a bad thing"? Having too much cortizone is also a bad thing. This will depress your immune system.This will make you more prone to bacteria and germs that cause you to become sick.

Week 6

This week we finished talking about the Autonomic nervous system or ANS and then went into our special senses. As you may know our special senses includes: taste, smell, sight, and hearing. We focused on learning the eye this week. The eye is an amazing sense, without it we would not be able to see all the wonderful things around us. The eye consist of the eyelashes, pupil, iris, lateral and medial commissure. Let's break this down a little. The eyelashes have glands that coats the lashes to keep the eyelashes from sticking and keeping dirt from coming into the eye. The pupil looks black but it is actually a hole. When your pupils constrict, this allows less light to enter the eye and when your pupils dilate, more light enters. There are three layers to the eye, including: the retina (inner layer), choroid, and the sclera (outer layer).

Cataracts is a problem people tend to have as they get older. Cataracts is caused when the fibers in the eye start to harden and the protein that usually helps to repair the eye has a hard time getting in the eye to do this. This results in a lens that becomes cloudy and hard to see through.

Week 5

This week we went over the cranial nerves and how the autonomic nervous system is broken down into the parasympathetic and the sympathetic. There are 12 cranial nerves and each have its own function.

Cranial Nerves:

1. Olfactory is for smell and is a sensory nerve

2. Optic is for vision and is also a sensory nerve

3. Ocukomotor controls eye movement and pupil constriction. This is a mixed nerve.

4. Trochlear also controls eye movement

5. Trigeminal controls the face, teeth, and chewing

6. abducens controls eye movement and is a motor nerve.

7. facial nerve controls pressure and facial expression.

8. Vestubulo-cochlear controls hearing and balence

9. Glosso=pharyngeal, containing swallowing muscles

10. Vagus controls sensation from ear canal, diaphargm, and chest

11. axxessory contains muscles of palate, neck, and some shoulder muscles

12. Hypoglossal controls tongue movement.



Next week we have break. I will take this time and start preparing for our next class.

Week 4

This week we reviewed mostly on the first meeting over the circle of Willis and CSF circulation. Then the next class we had a different professor. It's funny how you get so used to one professor all the time, when another one comes along, how different they teach. Anyway, we covered the peripheral nervous system. This is divided into somatic and autonomic divisions. The somatic division regulates voluntary skeletal muscle. The autonomic division deals with the glands and smooth muscle. Then we went over the cranial nerves There are twelve pairs of nerves: olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulo-cochlear, glosso-pharyngeal, vagus, accessory, and hypoglossal. They each have there own functions.

This relates to everyday living for people who have a disorder or disease relating to the nervous system. For example, someone who has Parkinson's disease or Paralysis.

Week 3

This week we had our first quiz. Because of our quiz we did not get as much lecture time as usual. I liked this lecture better than the past few because it was a faster pace and we covered more. This week we started going over the brain. Starting to cover the mennges, CSF circulation, blood flow, and the anatomy of the brain. We went through the circulatory pathway and the circle of Willis. You can find these on pages 774 and 758. The wrapping around the brain is two layers thick and the wrapping around the spinal cord is only one layer thick. This is what we went over for the brain so far.

This week in lab I was able to see a sheep brain and the inside of it. This helped having the hands on experience before talking about it in lecture. It is still early in the chapter but having hands on the brain before lecture helped understand the midbrain and hindbrain better.

Week 1 and 2

The past two weeks we have been talking about the nervous system. The nervous system is separated into two categories: the central nervous system (CNS)and the peripheral nervous system (PNS). The central nervous system consist of the brain and spinal cord. The peripheral nervous system includes all the nervous tissue outside the CNS. There are both similarities and differences to chemically and voltage regulated ion channels. They are both unique shaped and change shape allowing ions to move across the plasma membrane. The chemically regulated ion channels change by binding to a chemical whereas voltage ion channels change shape because of the electrical charge.

When learning about the nervous system I was unsure of the diseases related to this system until the last class we had. This is when we mentioned Alzheimer's Disease and how it related. I work with Alzheimer's patients on a regular basis so I see how they decline but I did not realize why they declined in the way they did until the other day. It is very interesting once you understand how the disease works.