 This video will cover an introduction to Human Anatomy Part 2. As we go, we'll cover the following study objectives. Describe anatomical position and use anatomical terminology to describe body directions, surfaces, or surface landmarks, and body planes. Identify the body cavities, four quadrants of the abdominal pelvic cavity, nine regions of the abdominal pelvic cavity, and the major organs in each cavity. Learning anatomy is like learning a new language. Like any language, it is essential that you practice speaking in order to use the vocabulary you'll need to practice using it over and over again until it becomes natural. There is a directional coordinate system that we use in order to describe directions in the body. In order to use this system, we have to start by assuming that the body is in anatomical position. That you see here, standing with the legs together, feet flat on the ground, arms down to the sides, palms facing forward. The directional terms we use will not change if the body is moved. So if the body is laying face up, it's in the supine position. If the body is laying face down, it's in the prone position. And the word superior means up when the body is in anatomical position. So towards the head. And superior will still mean towards the head, even if the subject is lying supine prone on their side, running, doing a handstand. The coordinate terms will always have the same meaning referring back to anatomical position. Here we see a figure illustrating the coordinate terms for anatomical directions, showing that anterior or ventral means towards the front and posterior or dorsal means towards the back. Superior or cranial means upward towards the head. And inferior is the opposite of superior. Inferior is down towards the feet. Caudal literally means towards the tail. And so caudal is also inferior towards the tail. And so let's practice with some of these terms. The head is superior to the shoulders, but the shoulders are superior to the hips. And so you see that these are relative terms. The shoulders can be superior to the hips and inferior to the neck and head. Medial means towards the midline and lateral is the opposite, meaning away from the midline towards the left or right side. And so the nose is medial to the eyes. Whereas the eyes are medial to the ears. And so the ears are lateral to the eyes, while the eyes are lateral to the nose. Deep means inward, so the heart is deep inside of the chest. Superficial is towards the surface, and so the skin is the most superficial. The ribs are superficial to the heart, but the ribs are deep to the skin. The humerus is the bone in the arm, and the humerus is deep to the muscles of the arm, like the biceps brachii. But the biceps brachii is deep to the skin. And so we see that the muscle is superficial to the bone and deep to the skin. When we're referring to structures on the limbs, distal means further away from the torso, towards the hands or feet, and proximal is the opposite, meaning closer to the point of attachment. And so the elbow is distal to the shoulder, distal to the arm. The elbow in the upper limb is distal to the arm where the humerus is located, but proximal to the wrist, and the elbow is proximal to the palm of the hand. And so the knee is distal to the thigh, but the knee is proximal to the ankle. Anatomous inclinations use specific terms to refer to regions of the body. Many of these terms come directly from Latin or Greek. Cephalic means head, and cephalic is the adjective term. Cephalon is the noun referring to head. The cranium is the region of the skull that surrounds the brain, and cranial refers is the adjective referring to that area. So the cranial region is the region surrounding the brain. And we can use these adjectives, forms to describe other things like muscles, cranial muscles, or cranial nerves, cranial blood vessels. And so the cranial nerves are nerves that travel in and out of the brain. Oral refers to the mouth. Mental refers to the chin. Frontal refers to the forehead. We'll see the frontal bone is a cranial bone on the superior and anterior parts of the cranium is the frontal bone in the forehead region. Nasal refers to the nose. Ocular refers to the eye. Othic refers to the ear. Bucal refers to the cheek. Cervical is the neck region. The cervical region is the neck. Cervix is the neck. You may have heard of the cervix, the region of the uterus. That's the narrow inferior opening of the uterus. So the cervix is the neck of the uterus. And the cervical region of the whole body is the neck, where the head attaches to the trunk. Thoracic is the chest. We'll see the thoracic cavity is a body cavity that contains the heart and lungs. The mammary is the breast region. The mammary region is where the mammary glands are located. Sometimes the literal historical meaning of a word is different than the technical anatomical meaning. And I'll give you some of these extra bits of information because they can be helpful to anchor the new terms in your vocabulary. Abdominal means belly. The abdominal cavity is the cavity that contains most of the digestive organs like the stomach and intestines. And the word abdomen or abdominal comes from the Latin word abderre, which means to hide as a reference to the organs hidden within the abdominal cavity. Umbilical is the region around the navel, around the belly button. Pelvic is the hip region. It comes from the Latin word for basin. And the pelvis bone has a basin-like shape that holds the urinary bladder and the reproductive organs in women, the uterus and ovaries are inside the pelvic cavity. In men, the prostate gland is inside the pelvic cavity. Ingueno is the groin region, the lateral regions of the groin. So the inferior part of the hip is the groin region. And the lateral parts where the thighs attach is the ingueno region. Whereas the midline, the medial part is the pubic region. So the pubic region is where the genitalia are located. And this name comes from the pubic bone, which is part of the pelvic bone that's found along the midline on the inferior and anterior. And where the two pubic bones come together is the pubic synthesis. Axillary is the region of the armpit, the axillary region is the armpit region. And we'll see the axillary nerves, axillary artery and axillary vein traveling through that region. Brachial is the arm. And so the humerus is the bone found in the brachial region. And we'll see the brachial artery and brachial vein travel along the humerus through the brachial region. Anticubital is the anterior of the elbow. And the most common place for blood to be taken to perform venopuncture, to withdraw blood, to get a sample of blood is the median cubital vein found in the anticubital region on the anterior of the elbow. So you probably have blood drawn from your median cubital vein on the anterior of your elbow. And that will help you remember, anticubital is the anterior of the elbow. Antibracial is the forearm. And so brachium is the arm. Brachial region is the arm that's the region that's proximal to the elbow on the upper limb. And the region that's distal to the elbow on the upper limb is the forearm, the antibracial region, where the bones inside that region are the radius and ulna. Carpal is the wrist region and the carpal bones are the bones found there. Palmar is the anterior of the hand, the palm of the hand, palmar. We'll see the metacarpal bones are found in the palmar region. And then digital refers to the fingers. The other word for the digital region is phalangeal. So phalangeal refers to fingers or toes and the phalanges are the bones found in the fingers and toes. The word phalangeal comes from the Greek word phallix, which referred to soldiers in a row, soldiers that are lined up in close order. And so the fingers and toes are all lined up parallel, similar to soldiers lined up in marching order. And that's where the word comes from. The largest finger, phallix, the thumb is the phallix. The largest toe is the phallix. And so the phallix is the thumb. And we'll see muscles that move the thumb will be called polysis, the extensor polysis, flexor polysis. See abductor polysis. The femoral region is the thigh and the largest bone in the body, the femur is found in the femoral region. We'll also see femoral nerve and femoral artery and femoral vein that I'll travel through the thigh region, the femoral region. The patella region is the knee and the patella is the kneecap, the flat bone on the anterior of the knee. The word patella comes from the Latin word for a little plate. And so you can see how the patella, the flat bone, the kneecap resembles a little plate. Crural refers to the leg. Tarsal refers to the ankle and the bones in the tarsal region are called the tarsal bones. The crural region is just the region of the leg that's distal. It's just the region of the lower limb that's distal to the knee. And so the crural region, the leg, is where the tibia and fibula are located. Whereas the femoral region is the part of the lower limb where the femur is located. And so the crural region or leg is just the region that's distal to the knee. The tarsal region is the ankle, the pedal region is the foot, and then the hullux is the big toe. Here we see a posterior view. The word acromial refers to the superior part of the shoulder. It comes from the Greek words acron for tip or summit and almost for shoulder. And so the superior part of the shoulder is the acromial region. We'll see the scapula, the shoulder bone, has an acromial process on the superior lateral region of the shoulder. And so the acromial region is the shoulder. The sacral region is the elbow, the lumbar region is the lower back and the sides of the abdomen. The lateral regions of the abdomen and the lower back, the lumbar region. The plantar region is the sole of the foot, the bottom, the inferior of the foot. It comes from the Latin word planta, meaning a sprout or twig. Now you can start to practice using these anatomical terms. Use the surface landmarks together with the directional coordinate terms. For example, we can say that the popliteal region is proximal to the sural region. So that's the posterior of the knee is proximal to the calf, the posterior of the leg. Or we could use the word superior. The popliteal region is superior to the sural region. Acromial is lateral to the cervical region, and acromial is proximal to the sacral region. Whereas the sacral region is proximal to the carpal region, the sacral region is distal to the brachial and acromial regions. To study the internal structure of the body, it is helpful to cut the body along standard sectional planes. The sagittal plane is a vertical plane that divides the body into right and left portions. If we make a slice right down the midline, that's a mid-sagittal. And a mid-sagittal section would produce two equal right and left halves of the body. A parasagittal section is off from the midline, producing one larger and one smaller section, but still through the sagittal plane to produce a right and left section. A frontal or coronal plane is another vertical plane, but the frontal or coronal plane divides the body into anterior and posterior portions. The transverse plane is a horizontal plane that divides the body into superior and inferior portions. And so the sagittal and frontal or coronal planes can also be called longitudinal planes, because they run parallel to the long axis of the body, and the transverse runs perpendicular to the long axis of the body. We can also use these terms when sectioning an organ. If we slice up an organ parallel to the long axis, then we're taking longitudinal sections, whereas a section that's perpendicular to the long axis is a transverse section. And if we make a slice that's not transverse or longitudinal, but at a different angle, that would be an oblique section. Body cavities are spaces that are closed to the outside and protect our organs within. For example, along the posterior of the body are the dorsal body cavities, the cranial cavity that protects the brain, and then the vertebral cavity that protects the spinal cord. On the anterior are the ventral body cavities, and the ventral body cavities, there's two large regions, the thoracic cavity, the chest region, and the abdominal pelvic cavity, the inferior part of the ventral body cavities. And the border between the thoracic cavity and abdominal pelvic cavity is the diaphragm. The diaphragm is a skeletal muscle that we contract in order to expand our lungs for breathing. The thoracic cavity is enclosed by the ribs, and the diaphragm is the inferior border. Inside of the thoracic cavity are the right and left pleural cavities which surround the lungs. And so the pleural cavities are lateral, and then there's the mediastinum, a cavity along the midline within the thoracic cavity. The pericardial cavity inside of the mediastinum surrounds the heart, and then the superior part of the mediastinum is called the superior mediastinum that contains some major blood vessels that travel through there. The trachea and esophagus also travels through the mediastinum. And then the abdominal pelvic cavity has two major regions, the abdominal cavity shown in red here and the pelvic cavity shown in green. The abdominal cavity contains most of the digestive organs like the stomach, the small intestines, the liver, the pancreas, the large intestines. It also contains the spleen and the kidneys, and the pelvic cavity contains the urinary bladder, and it also contains reproductive organs in women. The pelvic cavity contains the ovaries and the uterus, and during pregnancy the uterus would expand as the fetus grows. The uterus would expand and occupy a large portion of the abdominal cavity as well. The abdominal pelvic cavity can be subdivided into nine regions or four quadrants. Let's start by going through the organs found in the four quadrants. The right upper quadrant contains the right lobe of the liver, the gallbladder, the right kidney, and portions of the intestines. The left upper quadrant contains the left lobe of the liver, the left kidney, spleen, stomach, pancreas, and portions of the intestines. The right lower quadrant contains portions of the intestines including the cecum where the small intestine connects to the large intestine. And the appendix, a small attachment that hangs off of the cecum, and the appendix commonly becomes infected and is removed surgically. The right ureter is also found in the right lower quadrant traveling from the kidney down to the urinary bladder. The ureter transports urine from the kidney to the bladder. And in women, the right ovary is in the right lower quadrant. In men, the right spermatic cord is in the right lower quadrant. Then the left lower quadrant contains portions of the intestines including the left ureter, the left ovary in women, and the left spermatic cord in men. Now let's take a look at the nine abdominal pelvic regions. The umbilical region is the central region surrounding the belly button, the umbilical region. Inside of the umbilical region is a portion of the stomach as well as portions of the intestines. Just superior to the umbilical region is the epigastric region. Epigastric literally means upon the belly and the epigastric region contains the liver or a large portion of the liver and also contains the majority of the stomach. And so the stomach is found in the epigastric region. Then the hypogastric region is inferior to the umbilical region. This hypogastric literally means below the belly. Inside of the hypogastric region is the urinary bladder. There's also portions of the intestines. And in women, the uterus and ovaries. In men, the prostate. Now the lateral regions on the superior are the hypochondriac regions. The right hypochondriac region contains part of the right lobe of the liver whereas the left hypochondriac region contains the spleen. Then just lateral to the umbilical region are the lumbar regions. The right lumbar region contains portions of the intestines including the ascending colon that travels up along the right side. The left lumbar region contains the descending colon that travels down along the left side. And then the inferior lateral regions are called the iliac regions. They're also sometimes called the inguinal regions. And inside of the right iliac region is the cecum. The region of the large intestine or the small intestine drains its contents into the large intestine. And the left iliac region contains the sigmoid colon. The region of the large intestine that connects from the descending colon over to the rectum.