The epithelial tissue is characterized by different features. Cellularity: epithelial cells are separated by minimum extracellular material to seal each cell to the other. Specialized contacts: cells are joined to other cells by special junctions. There are many tight junctions in the epithelial tissue in order to contain and (for example) not to let fluids out of our skin and bodies. Polarity: there are two kind of epithelial surface, the first one is the apical (what’s exposed to the external world) the second is the basal surface (internal surface). Different things happen to each surface. Deep down the epithelial layer we find connective tissue, which is a different tissue type. This connective tissue supports the epithelial tissue. Even though the epithelial tissue is considered to be avascular, meaning it doesn’t have blood vessels, the basal surface is able to communicate with the connective tissue through some modifications in order to receive its nutrients. Epithelial tissue is innervated (has nerves instead of blood vessels). As the outside wall of the epithelial tissue is in constant interaction with the outside world, when the cells are damaged, the epithelial tissue is able to regenerate immediately. Looking at an epithelial diagram we see an apical surface with tight junctions sealed by KISS size. The basal region is completely different from the apical surface. The desmosome junction is in charge for cell to cell adhesion. The gap junction connects two cells by their cytoplasm so it doesn’t deal with the membrane. The epithelia classifies in simple where epithelia has a single layer or stratified epithelia when it has more than one layer. The shape of the cell can be squamous if its the shape of a plate (can be single layered or stratified), or cuboidal (single layered or stratified) or columnar (single layered or stratified). The epithelial tissue is also composed by glands. Endocrine don’t have ducts meaning they secrete straight into the surrounding fluid tissue. Exocrine glands on the other hand has ducts (exit). Unicellular exocrine glands also called goblet cell are in charge to produce mucus made of mucin and water which lubricates some of the inside body surface. The plasma membrane of it its very important as it determines what can come it and what can go out. In the nucleus we find CHROMATIN which is a mix of dna and the associated proteins (including amino acids). The discrete units are called chromosomes containing the genes. The chromosomes can’t leave the nucleus, they can only be rewritten in a different form. The ribosome, which look like little dots, are the ones that can remake the chromosomes and deliver it through Rough ER to the golgi apparatus. The golgi apparatus modifies the chromosomes and sends it again. This whole process takes a lot of energy which we get from the mitochondria. Connective tissue has structural elements: cells which is a primary cell type in charge of producing matrix. The cell type can be named in to three different names: osteoblast for bones, chondroblasts for cartilage and fibroblast for fibers. Fibroblast is the primary cell for the connective tissue. The connective tissue is vascularized so it contains blood vessels. Anatomy is the study of structure, physiology is the study of function, biology is structure equal function.The branches of anatomy are gross anatomy (large, what is visible to your eye), as opposed to microscopic anatomic (your eye needs to be helped to get the image better) and surface anatomy (dealing with the surface). There are a lot of different branches of anatomy: developmental anatomy (looks at the process of the development – egg / DNA start example), embryology (the study of the development during the embryo state), pathological anatomy or pathology (the study of when something goes wrong in its function), radiographic anatomy (x-rays), functional morphology ( things shapes and how they function). There is a wide anatomical terminology which is based on ancient greek and latin which is used worldwide. When you are dead you lose organization as you are not alive anymore. Your organism can build up on break down; it’s made up of working systems that can be broken down into organs including lunge, stomach, intestine, heart, brain, vessels etc. organs can also being break down into tissues like connective, muscular and nervous tissue. Then tissues can be broken down into cellular level which is the smallest living thing into our organism. Even cell has components tho like organelles (that can be broken down to molecules, atoms, subatomic particles). As these parts can be broken down, they can also build back up and vice versa. Subcellular particles work out together as a cell. Then when we have different cell working out together, they form tissues. We also have many type of tissue such as muscular tissue, cardiovascular tissue, epithelial tissue. These together form an organs. Organs working together produce organ systems, and many organ systems working together make an organism. Studying anatomy we have two different approaches: the systemic which is the study of anatomy looking at the system and the regional which studies anatomy by region. As both approaches have merit, the majority of the students tie together these two for a better understanding of anatomy. Intro to gross anatomy: the axial region includes everything but our limb. Appendicular region on the other hand includes limb arms and legs. If we subdivide this we see that axial region can be divided in cephalic cervical thoracic abdominal and pelvic. Going forward we can subdivide these categories more: cephalic in frontal, orbital, nasal, oral and mental. Thoracis in axillary, sternal and mammart, abdominal in umbilical and pelvic in inguinal (which means genital). The appendicular region subdivides as well into upper limb, manus, lower limb and pedal. These categories further divide in upper limb with acromial, brachial, antecubital, antebrachial and carpal. Manus subdivides in pollex, palmar, digital. Lower limb subdivides in coxal, femoral, patellar, crural and fibular (peroneal). Pedal divides in tarsal metatarsal digital and hallux. Superior is towards the upper body while inferior is away from the head. Anterior or ventral) refers to the front of the body or towards it. While posterior (or dorsal) refers to the back of the body or behind. Medial is towards the middle line of the body, lateral is moving away from the midline. Proximal refer to close to the part where limb and body trunk link. Distal is far away from the point where limb and body trunk touch. Superficial is at the surface of the body. Deep refers to the internal of the body. Ipsilateral is on the same side. Contralateral refers to opposite sides. The frontal section refers to the torso. Transverse section refers to the inferior view of the torso. The median plane divides right side from left side. Dorsal cavities are places in the dorsal side and it includes the cranial cavity which includes the brain and the vertebral cavity which includes the spinal cord. The ventral cavity is referred to the thoracic cavity and the diaphragm includes the abdominal and pelvic cavity. These cavities have no contact to the outside world unless we have an open surgery. That’s the only way they have contact with the outer world. Body cavities are associated with body membranes. The membranes are named depending of in which part of the body they are placed: lunges, ribs, parietal pleura, pleural cavity with serous fluid, visceral pleura, diaphragm. In between there are the intrapleura space that are filled with water and fluids. This space allows these fluids to slide constantly which supports your lungs from collapsing. The lung are surrounded by the pleura member, it has two walls the parietal and the visceral ( which means body organs). The heart is surrounded by a membrane called the parietal sac. It has a parietal side and a visceral side and fluid in the middle just like the lungs. The abdominal viscera has a serosae which is the peritoneum. This is a cross section or also called a transvert section. We can compare membranes as double walled and dead ends is a water balloon with a fist shoved in the middle of it. The abdominal region is divided into nine sections: the right hypochondriac, right lumbar region, right iliac or inguinal region. In the middle we find the epigastric, the umbilican and the hypogastric or pubic region and by the left we have the left hypochondriac, the left lumbar region and left iliac region. Deep down this surface made of nine regions we find organs: liver and gallbladder in the right hypochondriac, colon in the right lumbar region, cecum and appendix in the iliac or inguinal region. Stomach in the epigastric region, transverse and descending colon in the umbilican region, urinary bladder in the hypogastric region. Diaphragm and spleen by the left hypochondriac, descending colon of large intestine in the left pubic region, and the initial part of sigmoid colon in the left iliac region. This parts can move in specific conditions such as tumors, pregnancy etc… patients point of view are quadrants. Right and left upper quadrants and right and left lower quadrants. Tools used in biology are microscopies: these tools are used to examine structures that can’ be seen by a bare eye. There are two kind of microscopy light microscopy that uses photons. This tool lightens the structure with a beam of light also known as lower magnification. The other microscopy is the electron which uses electrons to illuminate the structure also known as higher magnification. This last one has a better resolution so its more useful to focus on smaller tissues. Microscope has Lenses to focus light. Lenses carry a negative charge. With a Transmission microscopy we are shooting a signal through our sample whether its a proton or its an electron (2D – flat image). The better the magnification the less/smaller the field. A light micrograph uses transmission microscopy as it has a flat image. To look effectively to a tissue/specimen we have to do some things: fix it, section it, stain it (to ensure we are blocking or letting the light in). Tissue is stained with acid which is high in ionic protons. During the process of getting the image right some minor distortion might occur also known as artifacts. As the process gets better these artifact lessen. Xray are transmission as they shoot their signal through the cell which get absorbed or rejected. Computed axial tomography is an advanced x ray technique to translate info into a better image. The digital subtraction angiography is also an advanced x ray technique as it removes the over layer of the image that’s been analyzed so we don’t have to do surgery to know what’s deep down. Used for small arteries and blockages for the study of heart and brain. PET uses isotopes which are injected inside your body in order to make images. Magnetic resonance imaging its a technique that creates HD pictures of soft tissues like water.