Anatomy Basics for Pre-Medical Students

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Anatomy Basics for Pre-Medical Students

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What is Anatomy?

Your class in Anatomy (Often paired with physiology) will examine the structure and function of the human body. We’re going to focus 90% of this lecture on just anatomy with the other 10% being a very brief look at physiology. 

This is a hard course. It’s a lot of memorization. Furthermore, if it includes physiology then you’ll also need to really understand and conceptualize the materials. However, it is also one of the most high yield of courses. You’ll need to know your Anatomy and Physiology in medical school and physiology in particular is widely tested on the MCAT. 

Approach to Learning Anatomy

Our advice to learning Anatomy and Physiology is to break it up into discrete systems. Then do the following four questions…

  1. Ask and Answer: What are the parts of the system?
  2. Ask and Answer: What is the purpose of this system?
  3. Ask and Answer: How does this system intact with other systems?
  4. Ask and Answer: What happens when the system breaks down?

The first question is all anatomy. The second and third question are all about physiology. The fourth question is part of the purpose of medical school. We’re mainly going to look at questions 1 and 2.

Anatomical Systems

  1. Skeletal System
  2. Muscular System
  3. Nervous System
  4. Circulatory System
  5. Respiratory System
  6. Digestive System
  7. Endocrine System
  8. Renal System
  9. Reproductive System
  10. Immune System
  11. Integumentary / Exocrine System
In Latin 'Anatomy' translates to "Madness". That's a joke. It actually translates to 'cutting up'.

We will briefly talk about each of these 11 systems. Since we don’t want this to get too unwieldy, this will really only be the Anatomy Basics. 

Skeletal System

Not to criticize The Count, but he does leave some information out of his song that you will need for your exam. Of course you need to be able to name every bone, but that’s not so hard. The naming patterns are pretty straight forward and the hardest ones to learn are always the hand, feet, and cranial bones. There’s a lot more though about bones you need to know for an anatomy class. Let’s list everything that is usually covered. 

  1. Cranial Bones.
  2. Appendicular Bones (Legs, Arms, Feet, & Hands).
  3. Axial Skeleton Bones.
  4. The structural support bone provides to our muscles.
  5. How bone is made and broken down.
    1. Osteoclasts, Osteoblasts, Vitamins
    2. Role of the Kidneys and Parathyroid Glands.

  6. The role bone plays in maintaining homeostasis throughout our bodies.
    1. Calcium is an important ion and does a lot of stuff.

  7. The role that bone plays in our immune system.
    1. Bone Marrow is amazing!

  8. How bones change as we age.
    1. Bones keep hardening while we’re children up until our teen years!
    2. Know the reason we ask older women to get DEXA Scans!

  9. Bone and bone marrow problems
    1. Fractures, Cancer, Osteoporosis. 
If you’re able to clearly answer all 9 of the topics above. You should be set for any questions about bones on an anatomy exam. 
 

Use a mnemonic to help learn those hand bones! Here’s a great one from Natee Jitthammachai!

Did You Know: A baby is born with 300 bones. These fuse together though and you wind up with 206 bones as an adult!

Some counts will say we have 213 bones, that’s because people are counting the fused sacral and coccyx bones separately. 

Muscular System

We’ve included a great physiology video above to show you how muscle’s work on a tissue and molecular level. This is a neat site for visualizing muscle motion. Look for their videos on YouTube also.  

Our Muscular system does a lot more then people realize. It is closely connected to our nervous system and one of the main drivers of our lymphatic system. Since this is just anatomy basics for pre-medical students and not something more in-depth, we won’t go that deep today. First let’s review the main topics in the muscular system. 

  1. The names of different muscles.
  2. The actions of different muscles. 
  3. The different types of muscle i.e.., Smooth vs. Striated.
  4. The role that muscles play in movement and locomotion.
  5. The role that muscle plays in our lymphatic system.
  6.  Muscle vs tendon injuries, i.e., sprains vs strains.
    1. A sprain is a muscle injury a strain is a tendon injury.
      1. Hint: T is in Tendon and T is in sTrain!

Honestly, 1 and 2 are going to give you the most trouble. There are far more muscles then bones – about 400 more. Also their names are more confusing then bones. Plus you may need to memorize origins, insertions, actions, and innervations for each muscle. So that’s about 3600 different things, if you’re dead-set on memorizing everything. Fortunately you probably won’t need to go that far. Let’s go over some tips for learning muscle anatomy.

  1. Be smart with what you study. If you don’t need to learn origins or attachments for your class, save the mental space to focus on other high yield things.
  2. Notice muscle names that repeat. If you learn it on one side, you’ve essentially learned it on the other side. 
  3. If working in a cadaver lab, pay special attention to the origins and attachments of the muscles. This will help you differentiate from a similar muscle. 
  4. Structure defines function. This is true for muscles too!
  5. Pair your learning of muscle nerves with your study of the nervous system.
  6. Watch videos of the muscles in action.
  7. Use a soft-tip pen to draw the muscle names on your own body, where the muscle is. Then each time you use that muscle during the day, take note of the action. Do not do this before an exam! 

Below we’ve included some pictures of some of the more difficult muscles to learn. 

Nervous System

The nervous system is right up there amongst the most difficult systems to learn. It’s much more then knowing the names of different nerves going to muscles and organs. You really need to know what the nerves do, how they work together, and what differentiates the central vs the peripheral nervous system. 

The Central Nervous System (CNS): The brain and spinal cord. As you imagine, the brain is massively complex. Many of the emergent functions in our body and functions which form our consciousness are actually bundles of nerves interacting in our CNS. These are often referred to as tracts and is a topic complicated to be many courses by itself. 

The Peripheral Nervous System (PNS): All of the nerves outside of our CNS. This includes the stuff going to and from our muscles and organs. Many different disease and chronic pain states effect the PNS. 

Tips for learning the Nervous System

  1. Pair the Nervous System with your study of muscles.
  2. Study the CNS and PNS as separate pieces. 
  3. Focus your CNS studying initially on the 12 Cranial Nerves.
  4. Next study the regions of the brain and what each lobe does.
  5. Take what you learned about the 12 Cranial Nerves and trace it back to the lobes. What regions do those cranial nerves visit? What do they do in those areas?
  6. Learn about testing the 12 Cranial Nerves – what problems can arise if a nerve is severed?
  7. Learn the spinal nerves. At what levels do the nerves exit? How does it change from cervical to thoracic and lumbar nerves?
  8. Learn your dermatomes! Match each peripheral spinal nerve with a dermatome.
  9. Learn your major PNS plexuses. The two big ones are the brachial plexus and lumbar plexus.
  10. Just like you did with the cranial nerves, trace the nerves from the plexuses back to the where they come from. Learn if they split off from other nerves
  11. If your taking a really advanced class in anatomy, learn where each nerve travels along the muscles, through the fascia, and through the bones. Link this to studying the skeletal anatomy of the skull.

Circulatory System

I wish the Amoeba Sisters taught me in medical school! Watch the video above for a great review and if you like their work subscribe!

Welcome to the circulatory system! This is your body’s major transportation system. Things, like hormones, platelets, oxygen, and nutrients, get places because of the circulatory system. Think of everything that is connected to your heart and bam you have it. This is all your Arteries, Veins, Capillaries, etc. 

This system is often paired and taught with the respiratory system, because they really work closely together. This is the last major systems that has tons of memorization related to it. Sure you have a lot to memorize with the endocrine, reproductive, immune, etc. systems. But the sheer number of vessels is in a difficulty class all on it’s own. To that effect, we recommend the following

  1. Learn the major pathways of the arteries and veins starting at the heart and going back to the heart.
  2. Pair learning most of the anatomy of the circulatory system with the anatomy of the skeletal and muscular systems.
  3. Learn the elements of the circulatory system found near the CNS  and organs with learning about those systems. Learn the Circle of Willis!
  4. Pay special attention to the branches that come off of the heart, the ascending aorta, and the descending aorta. These are confusing but high yield. 
  5.  Learn the divisions and sub-divisions. Not everything is an artery. There are arterioles, capillaries, veins, venules, etc. Know the difference between each division and key facts about it.
    1. Ex. Know the sizes Arteries are big. Capillaries are small.
    2. Ex. Oxygen exchange occurs at the level of the capillaries
    3. Ex. Arteries have no valves. Veins have valves.
      1. Do you know why?
  6. Know your heart anatomy!
    1. Human heart has 4 chambers
    2. Know the names of the chambers and the valves.
      1. Chamber Names: Right Atrium -> Right Ventricle -> Left Atrium -> Left Ventricle. 
      2. Valve Names: Tricuspid -> Pulmonary -> Mitral -> Aortic.
        1. Trouble remembering? Ask your mom to buy some toilet paper. “TP MA!”
  7. Know the key branches in the arms, legs, spine, and pelvis. This is very important to know if you are interested in becoming a surgeon one day!

Respiratory System

He’s no amoeba sisters, but Professor Dave is pretty awesome too! Make sure you subscribe to his channel if you like this video.

Take a deep breath. You’ve made it to the respiratory system. This system and the ones after it are going to get a bit shorter. Not because they’re less complicated, but rather because they are less memorization intensive. Here’s the big take away points… 

  1. Know how the circulatory and respiratory systems are connected.
  2. Be able to follow every beat of the heart and every breath in the body.
  3. Kind of mirroring the circulatory system, the respiratory system has anatomy that can be broken down into divisions and sub-divisions. Also general facts about the anatomy. 
    1. Left Lung has 2 Lobes. Right Lung has 3!
  4. Understand the role of the diaphragm in the respiratory system. Also understand how the other muscles of the thoracic cavity play a role too!
  5. Understand how the respiratory and lymphatic system are related. 

Digestive System

The Digestive System: This is the most delicious of systems and deceptively complicated. Part of the problem with learning the digestive system is that our everyday language is wrong. Have you ever had a stomach ache and pointed to around your bellybutton? What even is a belly? I’ve never prescribed medication for a bellyache.

Let’s start by following the path of food through your digestive system and talk about what happens at each step. 

  1. Food enters your mouth and is mashed up or masticated into smaller bits. Digestion also starts here with salivary amylase. 
  2. In a gulping motion your food travels down the nasopharynx and oropharynx skipping past the larynx (which is being closed by the epiglottis) and down your esophagus. 
  3. The food then enters your stomach, which is right under your diaphragm on the left side.
  4. Food in your stomach starts a whole bunch of hormones to be released and preps the rest of your body for digestion. The food also gets a good tumbling acid wash that helps to kill bad stuff that might be in the food.
  5. Your food  then passes into your duodenum, this is where digestion really gets going. The Gallbladder and Pancreatic enzymes are responsible for much of digestion. Not your stomach acid! 
  6. Next your food heads into the jejunum and ileum (small intestine). This is where absorption starts.
  7. Finally your food enters the large intestine, aka the colon. This is where we mainly reabsorb water. Most of the digestion has taken place at this point. 
  8. Anything left over is waste and gets expelled!

Endocrine System

I used the Crash Course videos extensively as a pre-medical student and you should too. Their presentations are great and they have topics about everything! Definitely use them to prep for hard subjects and to review to make sure you really understand the material. Also I highly recommend their videos on mitosis and meiosis.


The Endocrine System is amazingly complicated.
 Your hormones regulate everything in your body, from your growth and maturity into an adult, to your bone density, to even how much water is in your body. After four years of pre-med and four years of medical school I often still feel like a total novice when studying it. The good news is I have some hard earned tips that I can share with you, which may make your studying easier! More good news! As an undergraduate student, you’ll only need to know the basics. The really tough stuff comes with pathology and treatment of endocrine disorders, which is super complicated. The key to first studying Endocrine system is to… 

  1. Name all the major hormones.
    1. Group them by origin!
  2. Name where they come from.
  3. Name their precursors.
  4. Name where their precursors come from.
  5. Name why we release them.
  6. Name what they do.
  7. Name where they act in the body.

If you can do all 7 of these things then you are 100% ahead of the game and should be able to handle all the endocrine questions you get. We’re going to focus on 1,2,6,&7 right now.

 

For this lesson on Endocrine Basics, I just want you to focus on the Anterior Pituitary, Posterior Pituitary, Thyroid, and Adrenal Glands. There are more hormone releasing endocrine glands, but we don’t want to go overboard in this lesson. 

To find your pituitary gland, put your finger on your nose. Now your pointing right at it. No it’s not in your nose. Now take your second finger and put it on your temple. These two fingers together are pointing at the approximate location in your brain where the pituitary gland sits. People have an anterior and posterior pituitary. Let’s list their hormones and what those hormones do.

  • Anterior Pituitary (6 Main Hormones)
    • Adrenocorticotrophic Hormone (ACTH)
      • Function: Helps adrenal glands work, Stress
      • Target Organ: Adrenal Glands
    • Follicle-Stimulating Hormone (FSH)
      • Function: Reproduction
      • Target Organ: Reproductive Organs
    • Growth Hormone (GH)
      • Function: Growth (duh) 
      • Target Organ: Throughout Body 
    • Luteinizing Hormone (LH)
      • Function: Reproduction
      • Target Organ: Reproductive Organs
    • Prolactin (PRL)
      • Function: Milk Production
      • Target Organ: Breast
    • Thyroid-Stimulating Hormone (TSH)
      • Function: Controls Thyroid Gland
      • Target Organ: Thyroid
  • Posterior Pituitary (2 Hormones)
    • Oxytocin
      • Function: Social Bonding, Reproduction, Childbirth, Milk Production
      • Target Organ: Widespread, Reproductive Organs
    • Vasopressin
      • Function: Blood Pressure Control
      • Target Organ: Kidneys, Blood Vessels

Now let’s move down to the Thyroid Gland. Good news! You only need to remember a few brief things about the thyroid gland. To find the thyroid, feel your neck and follow it all the way down to your clavicles. Your thyroid is shaped like two wings that surround your throat, right around the area of the clavicles and suprasternal notch. 

What it Does: Think of your thyroid as the on/off switch for your metabolism. It does more then that, but metabolism is the thing I want you to associate with thyroid. TSH, a hormone we just learned about above, is the thing flicking the switch on and off. If you have problems making too little thyroid we call that hypothyroid and you tend to gain weight, feel cold, fatigued, and overall pretty lousy. If you have problems making too much thyroid we call that hyperthyroid, and you get the opposite effects – you lose weight, feel hot, but also fatigued and lousy (because your body is in hyperdrive). It’s a pretty common problem and doctors check for it all the time. 

The Adrenal Glands are the last system we’ll cover in this lecture. As you can see from the picture above, your adrenal glands sit on top of your kidneys like little hats. This puts them in a really good place to dump hormones into your blood stream. You’re probably familiar with adrenaline which comes from the center, or cortex, of the gland. However it also produces 3 other hormones. Let’s go over a hormone from each section, based on the location – working outside to inside.

  • The Outer Section
    • Hormone: Aldosterone
    • Purpose: Regulates Mineral Balance
    • Target: Kidneys, Areas Throughout Body
  • The Middle Section
    • Hormone: Glucocorticoids
    • Purpose: Regulates Glucose Metabolism
    • Target: Areas Throughout Body
  • The Inner Section
    • Hormone: Androgens
    • Purpose: Stimulates Masculinization
    • Target: Areas Throughout Body
  • The Center
    • Hormone: Epinephrine (Adrenaline)
    • Purpose: Stress, Fight or Flight!
    • Target: Areas Throughout Body

Notice that these hormones act throughout the body? That’s part of the benefit of them being on the kidneys. They can get into the bloodstream fast and go all over the place! 

Renal System

The Renal System is also very complicated. We won’t even try to go into all of the details that it’s due. Instead we’ll just cover some study tips for organizing how to approach the study of the Renal System. You want to organize your studying around the following 3 things.

  1. Know the purpose of the Renal System
    1. Blood Filtration * Urine Production
    2. Blood Pressure Control
    3. Electrolyte and Acid-Base Balance
  2. Know the Macro anatomy of the Renal System
    1. Kidneys, Ureters, Bladder, Urethra
  3. Know the Micro anatomy & its function in the Renal System.
    1. Glomeruli, Loop of Henle, etc. 

And, for a basic review, that’s about it. Of course, like I said at the start, the actual renal system is very complicated. When you study it in depth you’ll not only be learning about function and anatomy, but you’ll also be learning about how the renal system, the endocrine system, and the cardiovascular system all work together to maintain homeostasis. It’s actually incredibly complex and the source of many different diseases. 

Reproductive System

You get two systems for one in this section! Welcome to reproductive anatomy and physiology. Honestly, the anatomy part isn’t too had here. What’ll trip you up is the physiology – especially the hormones. Reproductive systems are almost always studied with endocrine systems, because so much of the complexity of studying endocrinology comes from the reproductive system. Here’s our tips.

  1. Study the Anatomy and Hormones separately. 
    1. Anatomy first. Hormones second.
  2. Organize the study of the female reproductive system around what is happening hormonally during menstruation. 
    1. Hormones have clear effects physiology and on the female anatomy during the menstrual cycle. 
  3. If you plan on being a doctor. Get comfortable talking about it!

Immune System

Hahahah! I got one more Amoeba Sisters video in. 

Talking about the immune system is a massive task. There’s no way I can do justice to it in a basic review of anatomy and physiology. So once again, I’ll just do a fly-bye, drop some essential info and facts and leave it to your classes to fill in the gaps.

Red Blood Cells vs White Blood Cells. Red’s carry oxygen, white’s are all about the immune system. We’ll focus on the whites.

Here’s a list of white blood cells (WBCs) and what they do.

  • Monocytes
    • Helps breakdown bacteria and foreign stuff. Active in fighting chronic infection.
  • Lymphocytes
    • Creates antibodies that fight stuff. More on this below.
  • Neutrophils
    • The most common WBC and they act as scavengers and destroyers of bacteria.
  • Basophils
    • These are involved in allergic reactions.
  • Eosinophils
    • These respond to parasites. 

The Lymphocytes are especially important and a type of WBC that we want to focus on now. As their name implies they come from lymph tissue. Ever have a doctor check for swollen lymph nodes? That doctor is checking for germinal centers pumping out lymphocytes.

There are tree types of lymphocytes. B Cells, T Cells, and Natural Killer Cells. The B cells and T cells have subtypes, but we’re not going to go into that much detail today. 

  1. B Cells: These make antibodies. There are several different types of antibodies. Consider them as the frontline soldiers against disease. 
  2. T Cells: These help to modify and tailor the body’s response to specific pathogens. Think of them like scouts and special forces. They scout out the invaders, call in help and run special ops in your body. 
  3. Natural Killer Cells: Badass name right? These are responsible for attacking viral and cancer cells. They also work with the other WBCS to coordinate attacks.

Integumentary / Exocrine System

This is a very skinteresting topic!

Skin and the exocrine system is far more then just skin. Here are some tips on memorizing everything you need to know. 

  • Know the layers of skin.
    • Stratum corneum
    • Stratum lucidum
    • Stratum granulosum
    • Stratum spinosum
    • Stratum basale
    • Dermis
  • Know where you find think and thick skin.
  • Know that thin and thick skin have different layers!
  • Know what each level looks like under a microscope.
  • Know what you can find at each level.
    • Capillaries, follicles, nerve bundles, sweat glands, etc!

We’re going to wrap up our lesson here and with the images below. We hope this was helpful! 

What Next?

Always work to tie new physiology you’re learning back to anatomy. Also don’t go too long without reviewing and refreshing your knowledge of the major stuff. What’s the major stuff? Heart, CNS, PNS anatomy. Major blood vessel and nervous system branches. Circle of Willis, Hormone names and functions, hand bone, arm muscle, and leg muscle names, and a host of other important things. You’ll know it’s important because you’ll see it over and over again. If you ever feel lost make sure to reach out for help on our activity feed!! 

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