Chapter 6: The Skeletal System

Welcome back! This week we are focusing in on the skeletal system which is discussed in GREAT detail in Chapter 6 of our Anatomy & Physiology book.  Bones are classified by the axial skeleton and the appendicular skeleton.  Then, they are further broken down into different classifications by their shape (long, short, flat and irregular bones).  The main functions of the skeletal system are support, protection, movement, mineral/growth factor storage, and blood cell formation.

There are a lot of different types of bone markings, bulges, depressions, and holes that are used for muscle, ligament, and tendon attachment, as joint surfaces, and lastly conduits for blood vessels and nerves. There are a bunch of names for there are different markings, I would recommend making notecards of all these terms for the test because these marking names seem like easy exam questions that you don’t want to miss! Here is a list of all the vocabulary that you should make sure you have memorized!

• ·         Process- any bony prominence
• ·         Tuberosity- rounded projection
• ·         Crest- narrow, prominent ridge of bone
• ·         Trochanter- large, blunt, irregular surface
• ·         Line- narrow ridge of bone
• ·         Tubercle- small rounded projection
• ·         Epicondyle- raised area above a condyle
• ·         Spine- sharp, slender projection
• ·         Head- bony expansion carried on a narrow neck
• ·         Facet- smooth, nearly flat articular surface
• ·         Condyle- rounded articular projection
• ·         Ramus- arm-like bar of bone
• ·         Meatus- canal-like passageway
• ·         Sinus- cavity within a bone
• ·         Fossa- shallow, basin-like depression
• ·         Groove- furrow
• ·         Fissure- narrow, slit-like opening
• ·         Foramen- round or oval opening through a bone

If you memorize these terms, it will be easier to be able to point out certain markings on specific bones during the exam. If you look at the structure that is being asked to identify, you will have these terms memorized and could use process of elimination to figure out the correct answer!

Next, I am briefly going to discuss the 2 different types of bone texture. The first is compact bone. This texture of bone is found right on the inside of the articular cartilage of the bone. It is mostly there for protection. The second texture of bone is spongy bone. This is like honeycomb of trabeculae foiled and it contains red or yellow bone marrow. It is located in the center of the bone.

Remember to keep reviewing and reading for more studying tips and key points from the book!

Word count: 390

Chapter 5; The Integumentary System

Hey guys! 

This week we are going over chapter 5 which is all about the integumentary system! 

First, lets talk about the skin, I would consider this a pretty important aspect of the integumentary system! The skin has 3 major regions that you need to remember...

1. Epidermis- the outer most protective shield of the body! Structurally, the epidermis is made up of keratinized (proteins) stratified squamous cells. There can be four or five layers of these cells.
2. Dermis- this is the middle region of the skin structure. This middle region makes up the majority of the skin. It is very tough and a leathery texture. This is made up of mainly fibrous connective tissue.
3. Hypodermis- You might see this called superficial fascia, as well. This is is your deep subcutaneous tissue skin. This is not “technically” part of the skin but it helps in the protection of the body, much like the epidermis and dermis.

Next, the chapter goes into detail about skin color. There are 3 different pigments that contribute to your skin color!

1. Melanin- responsible for yellow to reddish and brown-black pigment. This is a polymer made of amino acids. This is the time of pigment you think of when you get tan. When our skin is exposed to sunlight, melanin builds up and this causes our skin to darken visibly. Caucasians have little melanin because they are fair skinned.
2. Carotene- this is a yellow to orange pigment found in certain plant products (carrots).Carotene can be converted into Vitamin A which is important for normal vision as well as epidermal health
3. Hemoglobin- is the reddish pigment responsible for the pinkish hue of the skin. Since Caucasians are fair skinned because they have little melanin, the epidermis is pretty much see-through and this allows for the hemoglobin to show through.

Your skin color can tell you important things about your health;

• Jaundice (yellowish cast)- this usually signifies a liver disorder
• Blanching (Pale)- during fear, anger, and other types of emotional stress some people become pale. Also, this could be a sign of anemia or low blood pressure
• Bronzing- a bronze metallic appearance of the skin is a sign of Addison disease. 
• Bruises- reveals when blood has escaped from the circulation and clotted beneath the skin

I hope this quick breakdown of the integumentary system helps you understand the basics of chapter 5!

Word count: 398

Chapter 4: Tissues

Welcome back, students! This week we are going to go over the basics of Tissues in the human body! There are 4 main types of tissue; Epithelial, connective, muscle, and nerve. 

First, lets talk about Epithelial tissue. There are 3 types of Epithelial tissue; Cutaneous, mucus and serous. The cutaneous type is the tissue of your skin. The mucus tissue is the type of tissue that lines your viscera for example your digestive and respiratory track . Serous is the membrane sound in you ventral body cavity (remember the ventral body cavity is the cavities that house your organs). The main functions of the epithelial tissue is to supported by connective tissue, contains no blood vessels but supplied by nerve fibers, and regenerative. It is important that Epithelial tissue is regenerative because this function rapidly produces more skin cells if you ever get a cut or scrap. 

Second, Connective Tissue is the most abundant and widely distributed out of all the different types of tissue. There is proper connective tissue which is dense tissue and there is special tissue. The connective special tissue are the blood, cartilage, and bone tissue. The main functions of this tissue is support, protection, insulin and transportation. These special tissues have special cells chondroblasts for cartilage, osteoblasts for bones, and hematopoietic stem cells for blood. 

The muscle and nerve fiber are the least abundant type but that does not mean they arent important! Nervous tissue has branched neurons with long cellular process and support cells. Nervous tissue transmit electrical signals from sensory receptors and effectors (what we learned about a few blogs back!). Muscle tissue has two different types, skeletal and cardiac. The skeletal tissue is long with multiple nuclei. This particular tissue initiates and controls the voluntary movement in the body. The Cardiac muscle tissue is branchy with only one nucleus and also has interlocking discs that work as gap junctions. The function of the cardiac muscle tissue, as you may of guessed, pumps blood into the circulation. This type of tissue is found on the walls of the heart.

I hope this breakdown of the different types of tissues makes reading or rereading chapter 4 in the Human Anatomy and Physiology book!

Good Luck on your first semester exams!

Word Count: 375

Chapter 3: The Cell Cycle

This week, we are going to go into detail about the cell cycle (Mitosis) which is discussed in great detail in chapter 3! 

1. Interphase

    Cells in the human body are most of the time in this phase. This phase is when a cell is going through its normal routines and functions. This phase is not considered part of Mitosis. Genetic material in this phase is in the form of chromatin. The nucleus looks like its normal self here, the nucleus is visible (at least under a microscope). Even though the cell is going through its normal routine, the DNA is being replicated and preps for actual Mitosis.

1. Prophase

    Prophase is a long stage and often divided into early and late prophase.

Early- Chromatin forms sister chromosomes attached by the centromere. Spindle fibers are starting to be formed. 

Late- In late prophase, the nuclear envelope starts to break up and the spindle fibers that were formed earlier in prophase start to attach to the chromosomes. Also, the centrioles are heading to opposite polls of the cell.

When you look under the microscope at prophase, you can tell it apart because the nucleus looks like it has several holes in it. Also, sometimes the chromosomes look like little squiggles in the inside of the cell.

1. Metaphase

   In metaphase, the centrioles are at their opposite ends of the cell and the chromosomes are lined up on the metaphase plate. (That is easy to remember, during metaphase chromosomes are lined in the center of the cell on something that looks like an equator). In looking at this stage under a microscope, you can see the sister chromosomes all lined up in the center of the cell, for me, metaphase is the easiest phase to point out under a microscope because it is the most unique.

1. Anaphase

    In this stage, the centromeres of the sister chromosomes are pulled apart simultaneously and you can see chromosomes being pulled to opposite sides of the cells from the spindle fibers toward opposite centrioles. 

1. Telophase

    When the chromosomes are stopped moving is when telophase starts. It helps me to think of telophase as the opposite of prophase. Here, the chromosomes condense and turn back into chromatin. The nuclear envelope starts to reform around the chromosomes. Telophase is hard for me to point out in the microscope because it looks similar to other phases. It helps me to look for a cleavage furrow, it looks like siamese twin cells, they are still connected but you can still see the 2 separate  cells. 

1. Cytokinesis

   Mitosis ends with the split of the cytoplasm to form 2 identical cells

I hope this breakdown of the cell cycle helps you remember certain phases and also help you during lab practical!

Word count: 437

Chapter 2: Part 2

       The second part of the chapter continues to go into depth on chemistry. There are several other key aspects of chemistry that are important when learning about anatomy and physiology. First, let us go over what polar and nonpolar covalent bonds mean. Nonpolar covalent bonds have electrons that are shared equally.  This produces electron balance, which means that no side of the molecule is charged. An example of a nonpolar molecule is CO2. Polar covalent bonds are when the electrons are shared unequally, which means the atoms in the bond can have different charges. This creates something called a dipole. A dipole means one side of the molecules electronegative and the other side is electropositive.  An example of a polar molecule is water, H2O. Polar and nonpolar molecules are important in anatomy and physiology when learning about different parts of the cell.

      A great example of how polar and nonpolar molecules work is the cell membrane. When looking at a cell membrane up close it has a bilayer, two layer, and membrane. This membrane is made up of phospholipids which have a polar and nonpolar side.  The inside of the bilayer is nonpolar and the outsides are polar. This is important for the cell because it allows cells to work well with water in the cell and outside of the cell. Molecules need to pass through the cell membrane in order to feed the cell and also get things out of the cell.

The second thing I am going to discuss is different reactions.

Synthesis Reactions           A+B-àAB

• ·         Taking small molecules and making them big
• ·         anabolic reaction
• ·         always involved bond formation

Decomposition reactions   ABà A+B

• ·         breaking down a molecule into smaller molecules
• ·         catabolic reaction
• ·         reverse of synthesis

Exchange reactions           AB+ CàAC + B

• ·         AKA displacement reaction
• ·         Involving both synthesis and decomposition
• ·         Example: ATP transfers its terminal phosphate group to glucose

Oxidation reactions

• ·         AKA Redox reactions
• ·         Food fuels are broke down for energy
• ·         Involve exchange reaction between reactants
• ·         If the products added a Hydrogen is it called a Reduction
• ·         If the products gave a Hydrogen it is oxidize

     A mnemonic device I use to remember which reaction is reduction or oxidation is

           LEO SAYS GER

    Lose an electron= oxidized

    Gain an electron= Reduction

Tune in next week for Chapter 3 review!

word count: 362

Chapter 2: Basic Chemistry (Part 1)

Chapter 2 in the Human Anatomy & Physiology is all about chemistry! This isn’t always everybody’s favorite topic so I am going to break down the chapter into 2 blogs because it has A LOT of information! Hopefully this post helps break down the basics of chemistry and is helpful for studying!

First, let’s go over the definition of matter. The authors define matter as anything that has mass and occupies space. Matter can be found in 3 different states, solid, liquid, and gas. All matter is composed of elements, substances that can’t be broken down into simpler substances, and these elements have different chemical and physical properties. Atoms, which make up elements, are what give these elements their physical and chemical properties. It helps me to look at the periodic table when discussing elements because it has pretty much everything you need to know about them right on the table!

http://paphysicalscience.wikispaces.com/periodic+table+of+elements

As you can see, the diagram shows you a few different parts. The element symbol is the abbreviation of the element name, which for this diagram is C.  The atomic number of carbon is 6. The atomic number of an element is the number of protons the element has in the nucleus. This is important for finding out how many electrons and neutrons there are in an element! Lastly, the atomic weight of the element is located usually on the under the element name. The atomic weight is the average mass of the element.

Now that we’ve gone over a little about the different parts of the periodic table, I want to discuss a little about the different types of chemical bonds. An Ionic bond is when atoms gain or lose electrons and comes charged, but the number of protons remains the same. A covalent bond is the sharing of 2 or more valence shell electrons; this allows each atom to fill its valence shell. Lastly, hydrogen bonds are an attractive bond or force between an electropositive hydrogen and another electronegative atom from another molecule. Remember about hydrogen bonds is that they are not a true bond!

http://www.cheezburger.com/

I hope this basic overview of chemistry from the first part of chapter 2 is helpful! Check back next week for chapter 2: part 2!

Word Count: 371

Chapter 1: The Human Body: An Orientation

In chapter 1, Marieb and Hoehn of our Anatomy and Physiology book, the author goes over the basics about anatomy and physiology. They stress how anatomy and physiology go hand in hand. They state the definition of anatomy as “the study of structure of body parts and their relationship with one another.” The author continues by defining physiology as “the study of the function of different body parts.” The main point of the definitions of anatomy and physiology is that they work off each other. The structure of a body part reflects on what the function of that body part would do.  After the basic summary of what this book and chapter is about, the authors go into describing the different levels of structural organization. There is chemical organization, which are atoms, molecules, and organelles. There are cellular systems which are cells and Tissue which are groups of similar cells. Next, organs which contain 2 or more types of tissue, organ systems which are organs working closely today. Lastly, Organismal which are all the organs working together. Here is a diagram to visually understand the levels of structures. 


http://www2.lbsdk12.com/science/Anatomy/anatomyunit101.html

Human are multicellular in order to function, these cell depend on organ systems in order to survive.    Body cells are interdependent on each other which basically means that one system can’t work alone, if one thing changes then things in other systems will also have to change. The body also likes to keep homeostasis or balance in its environment, such as its internal temperature. In order to keep this homeostasis environment the body has receptors, a control center, and effectors. The receptor is a senor and its job is to monitor the environment of the body and respond to different stimuli. The receptors bring the information to the control center which determines the set point at which a variable needs to be maintained. After the control center receives the information from the receptor it determines what needs to be done to maintain balance in the body. Once it decides what needs to be done, the control center tells the effectors what needs to be done. The effector is usually a muscle or a gland which acts upon what the control center ordered them. The response the effector makes either reduces or stimulates stimuli. This is either a negative (reduces) or positive (stimulates) feedback. Negative feedback is much more common that positive feedback. Negative feedback is when the response given off reduces or shuts off the original stimulus. This is when the stimulus reaches its set point such as body temperature. Once the body researches its set point, the normal body temperature, the control center tells the receptors to stop producing the stimuli that is increasing the body temperature. Positive feedback is very rare, it is when the control center wants the response to speed up or enhance the stimuli because it isn’t doing enough. Such as giving labor, the exaggeration the production of oxytocin in a pregnant female gives a woman extreme contractions she needs in order to deliver the body. People wouldn’t be able to function if there was a lot of positive feedback. Referring back to the giving labor example, the contractions would keep getting bigger and bigger and the cervix would never go back to the normal size after the delivery.

http://www.tokresource.org/tok_classes/enviro/syllabus_content/1.1_Systems/index.htm

Here is your summary of key points for chapter 1 in the anatomy and physiology book! Hope this helped your understanding of chapter 1, or at least another review of the information to help the memorizing.