Dissectible Me 5 minute anatomy

A common request is for me to summarise the nerves of the lower limb and how they innervate the muscles. If we think about the parts of the lower limb (thigh, leg and foot) and their compartments we can link each nerve to each compartment and then easily remember every nerve that innervates every muscle. Well, that's the theory.  

An aortic dissection occurs when the innermost layer of the aorta tears and blood pushes into the walls of the aorta, separating the layers and causing some very dangerous problems. Let's talk through this process and think about the anatomy that might also be affected.

The anatomical snuff box describes a clinically useful surface anatomy landmark on the back of the thumb at the wrist, outlined by a triangular set of tendons. In here we find the scaphoid bone and some other structures. I'll try to describe what you can find here on yourself.

There is so much that we could talk about when looking at the anatomy of the small intestine, but if I only had 5 minutes what would I choose as the most important ideas?

The axilla is the armpit, and an anatomical space linking the torso with the upper limb. Let's define its borders so we better understand where it is and then we can talk briefly about the structures that we find passing through or residing in there. 

The anatomy of this slender U-shaped bone in the neck at the top of the larynx is crucial to the normal functions of the larynx and swallowing, but why?

Squeezing in a little more detail about the parasympathetic nervous system I can talk about all of the cranial nerves that carry parasympathetic neurones, brainstem nuclei, the parasympathetic ganglia of the head and the functions of this division of the nervous system in about 5 minutes.  

What are the most important points about the functional anatomy of the sympathetic nervous system? And what central nervous system structures drive the sympathetic nervous system? In 5ish minutes?

I'll try to describe what it is and its anatomy in a concise 5 minutes. Ish.

We can use surface anatomy landmarks to define triangles in the neck to help us locate anatomical structures deep to the skin. Within the posterior triangle of the neck we can find the roots of the brachial plexus, the subclavian artery and vein, and most importantly the accessory nerve (CN XI).

The anterior triangle of the neck is a region defined by surface anatomy landmarks that help you locate critical anatomical structures. Let's palpate together!

The bones, ligaments and synovial bits of the hip joint between the acetabulum of the pelvis and the head of the femur.

The lumbosacral plexus is the anatomy of the low back and pelvis that forms the major nerves of the lower abdomen, pelvis and lower limb. It is not as susceptible to injury as the brachial plexus so clinically we understand the anatomy of this plexus a little differently, but it is important to be able to recall the spinal nerve roots of the major nerves here and the functions that will be lost if injured.

Understanding the anatomy of upper and lower motor neurones can be very useful when trying to use the results of an examination, signs and symptoms to diagnose the location of a neurological lesion. 

Spinal tracts are bundles of neuronal axons that run through the spinal cord and brainstem. If we think about how neurones work, how they are bundled together with similar functions, which direction the action potentials are running in and the names of these tracts, we can remember what they all do.

Referred pain is felt at a different location in the body from the site that is causing the pain. There seems to be an anatomical reason for this and understanding the theories can help with diagnosis and patient care.

Talking about the anatomy of the urethra and better understanding why women get more urinary tract infections than men.

The radial and ulnar arteries both supply blood to the hand and meet as two arches that send branches off to the fingers. This anatomy gives redundancy for the blood supply to the hand so let's talk about where these arteries run and how they branch.

The names of the movements of the thumb can be tricky to remember, but knowing the movements gives you the names of the muscles that cause these movements.

Relating the movements of the hand to the nerves responsible is an important clinical skill. Let's see if I can describe the movements of the wrist and fingers, and the nerves that trigger these movements in 5 minutes.

The anatomy of erection of the clitoris and the penis is very similar and a rather neat mechanism involving the parasympathetic nervous system.

Did you know that alongside the pulmonary arteries taking poorly oxygenated blood to the lungs run bronchial arteries carrying well oxygenated blood? Where do they come from, and where does this blood go to?

The ureters carry urine from the kidneys to the bladder, and are muscular tubes lined by a urothelium. They use peristaltic contractions to send the urine in the right direction so do not rely on gravity, and because they run from the mid-abdomen down to the true pelvis they receive a number of arterial branches as they travel and likewise use nerves from a number of spinal levels to send the pain of a kidney stone obstruction back to the brain.

The kidneys manage the amount of water and salts in the body, regulate blood pressure, stimulate red blood cell synthesis, and remove toxins among other jobs. Let's talk about the key points of their anatomy for 5 minutes.

This episode explores the anatomy of the clavicle or collarbone, the smallest long bone in the human body. We'll dive into its shape, size, joints, etymology, & muscular attachments. Ever wondered about the clavicles of a T. rex? By the end of this episode, you wonder no more!

The anatomy of breathing uses a number of muscles to change pressures inside the thorax and adds more muscles and more movements when we need more air. At rest you're just using your diaphragm and the elastic recoil of the lungs themselves, when you're a little more active and running around the intercostal muscles start to move the ribs, and when you really need to pull air in and push it out you can take advantage of accessory muscles of respiration that might not normally move the ribs.

In this episode, we unravel the anatomy of the cochlea, the intricate organ that makes hearing possible. Discover how this tiny structure converts sound waves into electrical impulses, bridging the gap between the ear and the brain.

Three layers of intercostal muscles run between the ribs to form the thoracic wall, resist the pressure changes of respiration and move the ribs. What would happen if these muscles were not there?

Lymph nodes are little bean shaped structures filled with the cells of the immune system and dotted around the body. Pathogens from skin injuries or that enter the body in other ways are passed to a lymph node and the cells here can respond. They are major parts of the immune system but metastatic cancer cells may also pass here, get stuck and continue to proliferate. This is important anatomy then, so let's quickly talk about it in around 5 minutes of podcast world time.

Swallowing is a sequence of events that must occur in a well ordered manner to ensure food and drink goes to the oesophagus and not into the airway. What is this sequence and what cranial nerves do we need to worry about?

The popliteal fossa is posterior to the knee joint and in here we can find some major blood vessels and nerves. We will describe the boundaries of this fossa, the major structures that run through here, why this is useful clinical information and a couple of notes about remembering their names correctly.

Astrocytes are cells in the central nervous system crucial for supporting neurones and their function. A glioblastoma is a dangerous, rapidly growing type of brain tumour. Guess how they are linked.  

Neurones are the major cells of the nervous system, but how do they work, how are they arranged, and what are the other cells of the nervous system?

The anatomy of the airway is incredibly important and fairly simple. The structures of the trachea and bronchi are adapted tubes that don't collapse with changes in pressure, and the mucociliary escalator has an important protective role.

The mediastinum is a region within the thorax between the lungs. In here we find the heart, great vessels, trachea, oesophagus and other anatomical structures. We can further describe where these structures are by dividing the mediastinum up into superior and inferior parts, and the inferior mediastinum up into anterior, middle and posterior medastinal compartments.

The anatomy of the superior vena cava and inferior vena cava in 5 minutes, with a little extra about anastomoses. These are the largest and some of the most important veins in the body.

How do skeletal muscle cells (myocytes) change their length? How does this relate to the different types of contractions that we see in gross anatomy and rigor mortis?

The parathyroid glands are vital as they help regulate blood calcium levels. Where are they?

Is the amygdala the fear centre of the brain? What's the anatomy here?

The sinoatrial node is the pacemaker of the heart. Let's talk about it in a little more detail.

The saphenous veins are superficial veins of the lower limbs. Why do they become varicose veins and why are they used in CABG surgery? What is CABG?

The coeliac trunk is a branch of the aorta in the abdomen that supplies blood to the stomach, liver, gallbladder, pancreas, spleen and parts of the duodenum and oesophagus. It is important because its branches supply blood to important organs but also because stomach and duodenal ulcers can erode through these arteries and cause significant bleeding. The anatomy here is difficult to describe but let's try and describe the branches of the coeliac trunk and how they supply blood to the organs that they are reponsible for.

Does thinking about the anatomy of the limbic system fill you with dread? That's your limbic system in action. Find out more in just 5 minutes in this podcast.

The basal ganglia should be called the basal nuclei, and are also referred to as the corpus striatum. This demonstrates one of the problems with studying neuroanatomy as terms seem to overlap. Let's talk about what the basal ganglia are, what they do, some of this terminology and what they have to do with Parkinson's disease.

The enteric nervous system describes the nerves of the gastrointestinal tract that autonomously regulate much of its function. Sometimes called the second brain it is a complex network of sensory inputs linked to motor outputs organised into two major plexuses running the entire length of the gut.

The phrenic nerve is well known for its role in innervating the diaphragm and its roots in the C3, 4 and 5 spinal nerves. It also innervates the pericardium, is implicated in the runner's stitch pain and can be responsible for pain in the shoulder.

The largest nerve in the body has many spinal nerve roots in the low back that are often the cause of pain in the lower limb. Let's quickly describe the anatomy of this huge nerve.

One of the huge reasons that exercise and a good diet are so important is atherosclerosis. This pathology describes a change to the walls of arteries that can cause narrowing, rupture or blocking of an artery. If this occurs in an artery supplying blood to the heart or the brain this will probably cause death, and is a leading cause of death in western countries.

It's the largest organ in the body (or on the body)? You can't live without it, it is an entire system of the body (the integumentary system), it is the major sensory organ, and it gets wrinkly as you get older. Skin!

There are only four tissues that make up the body (epithelial, connective, muscle and nervous). We should talk about epithelia and carcinoma.

Erb's palsy is an upper brachial plexus injury and is an example of why learning the anatomy of the brachial plexus is important. How does this palsy present and what has been injured?