Dissectible Me 5 minute anatomy

The midbrain is the upper part of the brainstem. In here we find tracts running to and from the spinal cord and cerebrum. We find nuclei and groups of neurones such as the substantia nigra, red nucleus, periaqueductal grey, colliculi and reticular formation. Cranial nerves III and IV come out of the brainstem. What do all of these things do? What does all this mean? 

Quadriceps femoris and the hamstrings are powerful extensors and flexors of the knee respectively, but they also cross the hip joint. Let's talk about their anatomy. 

The pelvic floor (or pelvic diaphragm) describes the structures at the lowest point of the pelvis, largely muscles, that support the pelvic organs directly and everything else inside the torso. Let's explain concisely the important anatomy here.

The flexor tendons of the fingers run into synovial tunnels that let them move freely as we strengthen and relax our grip. These tunnels are tied down to the bone by some extraordinarily strong annular and cruciform pulleys that keep the tendons close to the bone. Let's describe their anatomy and their naming. 

There are 3 arches in the foot: a medial longitudinal arch, a lateral longitudinal arch and a transverse arch. Why do humans have arches in their feet? What's the anatomy here? 

The plantar aponeurosis (or plantar fascia) is a very strong connective structure on the sole of the foot, deep to the skin, running from the heel bone to the toes. It protects the structures in the plantar foot, supports the longitudinal arches and returns stored energy during the gait cycle to improve the efficiency of walking and running. It can be injured leading to pain anterior to the calcaneus on the plantar foot and a condition called plantar fasciitis. 

The uterus lies in the pelvis and has three layers. The endometrium is a specialised layer able to receive a blastocyst and with it form a placenta to support a growing foetus. The myometrium is a thick smooth muscle layer able to stretch to match the growth of the developing foetus and then expel it at birth. The perimetrium is a thin covering to the uterus that is largely peritoneum. The cervix is the entrance to the body of the uterus and the uterine tubes connect to the ovaries. Ligaments, endopelvic fascia and the levator ani muscle group all...

What is the musculovenous pump? How does it help lift all that blood from your legs back up to your heart when you're walking around? Let's talk about the veins and their valves, where they lie in the lower limbs and the deep fascia that surrounds them and the muscles. 

The femoral triangle is an anatomical region in the upper anterior thigh bordered by the inguinal ligament, sartorius muscle and adductor longus muscle. In here we find the femoral nerve, femoral artery and femoral vein with some lymph nodes. These large blood vessels can be used to access vascular structures in the lower limb and torso, including the heart. 

The ovum (or oocyte or egg) passes from the ovary into the uterine tube (or Fallopian tube). Spermatozoa pass from the vagina through the cervix into the uterus and then into the uterine tube. Fertilisation happens here, in the uterine tube. How does all this happen? What is an ectopic pregnancy?

Let me try to describe the locations, functions and innervation of the major muscles of the shoulder joint: pectoralis major, latissimus dorsi, serratus anterior, deltoid, trapezius and the rhomboids. 

In short, the peripheral nervous system is all of the nervous tissue that is not in the central nervous system. Except for cranial nerves I and II. What about autonomic nerves? What are ganglia? And the enteric nervous system? 

What do we mean by "the central nervous system"? What anatomical structures are included when we say, "the brain"? Are cranial nerves part of the central nervous system? What is inside the spinal cord? 

Let me introduce to you the four parasympathetic ganglia of the head. Meet the ciliary ganglion, the otic ganglion, the pterygopalatine ganglion and the submandibular ganglion. Why do they exist and what do they do?

The foetus gets its oxygen from the placenta and not from the lungs when in the uterus. The lungs are still growing and little blood flows through them. The foramen ovale is a flap valve that lets blood pass from the right atrium directly into the left atrium, avoiding the lungs. From the left side of the heart this blood will flow into the aorta and off around the body. The ductus arteriosus is a vessel that allows blood to flow from the pulmonary trunk through and into the aorta, again avoiding going through the lungs. At birth both...

How are the tonsils associated with the cerebellum? How can they be herniated and what does this mean? What is coning? Why is this an important sign? I'll explain.

In 5 minutes, what is the anatomy of the cerebellum and what does it do? Why does it have 80% of all of the neurones of the brain? Why does it look like a little brain?

The spermatic cord carries all the things the testis needs to and from the torso. What is the spermatic cord made of, what are its layers, where do these layers come from, and what are all the things inside the spermatic cord?

How can understanding the embryology of the gastrointestinal tract as foregut, midgut and hindgut help us understand the blood supply and venous drainage of the adult GI tract?

"Soma" means "of the body" so what is the somatic nervous system? How is this dividing up of the nervous system useful? I'll try to describe this neuroanatomy concept in 5 minutes.

The ovarian artery branches from the aorta and supplies blood to the ovary. The uterine artery branches from the internal iliac artery and supplies blood to the uterus. But they link, and in doing so provide a collateral circulation route between the abdominal aorta and pelvic internal iliac artery. Let's discuss.

What is the anatomy behind Trendelenburg gait? Why does the hip drop? Which hip drops? Which side is the weakness on? What might cause this? I'll try to describe this clearly in 5 minutes.

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?

The aorta is the major artery that runs the length of the torso, has some cool curves, and supplies blood to everything.

Gait is complicated, and Trendelenburg gait is an abnormal gait caused by a weakness or paralysis of the gluteus medius and minimus muscles. How does this work? (Or not work)?

The adrenal glands are vital and the cortex and medulla of each have different functions. Let's talk about their anatomy and what they do.

The sacroiliac joint is a very strong joint that takes the load of the torso from the vertebral column and sends it to the pelvis and lower limbs. It is a synovial joint that allows a little movement and is strongly supported by ligaments. Pain here is often caused by the joint being pulled too far by the large muscles that cross it or that move the pelvis.

The ribs are a series of 12 curving bones on either side of the torso forming the walls of the thorax and upper abdomen. Let's talk about their parts and how they move.

The pancreas is an organ that most people know about because of its job in producing insulin and managing blood sugar levels. When this doesn't work correctly diabetes develops. It has other endocrine roles and exocrine jobs too, in digestion. Let's talk about where it is in the body and some of the details of the anatomy of this vital organ in 5 minutesish.

The pelvis has two halves (left and right) but each half is also made up of three bones. Let's look at the anatomy of the ilium, ischium and pubis bones and how they link to the back and lower limb.

The nuchal ligament is in the back of your neck and you can feel it when you flex your neck forwards. What does it do and where does it come from?

The pudendal nerve is responsible for sensation from the external genitalia and the perineum, and for motor innervation of the muscles here including the urethral and anal sphincters. It comes from the sacral plexus, so how does it get to the perineum?

In this episode, let’s use the common complaint of elbow pain as a vector to explore the anatomy around the elbow.

Terms covered this week: medial & lateral epicondyle. Pronation & supination. Medial epicondylitis aka golfer’s elbow.  Lateral epicondylitis aka tennis elbow. Flexor muscles, specifically flexor digitorum muscles (superficialis & profundus), flexor carpi ulnaris, flexor carpi radialis, palmaris longus & pronator teres. The extensor muscles, mainly the extensor carpi radialis longus & brevis, extensor carpi ulnaris, extensor digitorum and the supinator muscles.

Let’s discuss the clear transparent tissue that sits anterior to the pupil and iris of your eye. Today we will explore the 5 layers of this tissue and link back to their function. There may be more to this area of anatomy than initially meets the eye……😶

Terms covered this week: the cornea, sclera, and progenitor cells. The 5 layers of the cornea are; the epithelium, the Bowmen’s layer (aka the anterior limiting membrane), the stroma, Descemet’s membrane (aka the posterior limiting membrane) and the endothelium layer. The debated sixth layer is also mentioned which is called Dua’s

The anatomy of venous drainage of the thoracic wall. What is the azygos venous system? Where is it found? Why is it important & interesting?

Terms covered this week, The azygos, hemiazygos & accessory hemiazygos veins.

We are back! Pun intended. In this episode, Sam will discuss the very important structure that exists between the vertebrae of your spine. The fibrocartilaginous intervertebral disk. This mobile, compressible, and stabilising tissue is integral for a happy healthy spine.

Terms covered this week: The annulus fibrosus & the nucleus pulposus. Type I & type II collagen. Vertebral endplate & disk herniation.

An anatomist’s ramblings on the optic nerve, colour vision & visual decussation.

Terms covered this week: The retina & its rod and cone cells. The optic nerve, optic chiasm & optic tract. Trichromats, dichromats, tetrachromats & achromatopsia.

Let’s discuss the sheets of connective tissue in the abdominal cavity, aka the peritoneum. Let’s explore how the folds of this membrane are called different things depending on how many folds there are, & how these folds form spaces……that us anatomists also name. In addition to the terminology, let's discuss the functions & clinical relevance of all these membranes, to justify knowing them.

Terms covered this week: The peritoneum & the parietal & visceral iterations of this. Peritoneal fluid. The mesentery. The greater & lesser omentum. The greater & lesser sacs. Finally, what on earth is meant by retroperitoneal?

In this episode lend me your ears, to understand your eyes. Let’s cover some basic ophthalmic anatomy in a whistle-stop tour of the anatomy of the eye.

Terms covered this week include the cornea, conjunctiva & sclera.  The iris, pupil, ciliary muscles, suspensory ligaments & the lens. The retina including its rod and cone cells. Finally, the aqueous and vitreous humours fill in the gaps. 

Following the Meninges podcast, this soundbite is dedicated to the anatomy of bleeds inside the skull. 

Terms covered this week include the cerebral arteries & subarachnoid haemorrhages. Cerebral bridging veins & subdural haemorrhages. Meningeal arteries & extra/epidural haemorrhages. 

In this episode, we discuss the three connective tissue layers that surround the brain & spinal cord. 

Terms covered this week are the dura mater, the arachnoid mater & pia mater. The leptomeninges & subarachnoid space. We also discuss meningitis.

Muscles & movements of the hip joint in 5 minutes or less! This is a challenge, but here we aim to provide a broad overview of the hip muscles, the movements of these muscles & their innervation.

Terms covered this week: The movements of the hip, flexion, extension, adduction, abduction, and internal & external rotation. The muscles of the hip: iliacus, psoas major & rectus femoris. Sartorius & pectineus. Gluteus maximus & the hamstrings. Gluteus medius & gluteus minimus. Gracilis & the adductor muscles (longus, brevis & magnus). The six lateral rotators of the hip: obturator internus & externus. Pyriformis, quadratus femoris & gemellus superior & inferior. The superior & inferior...

Completing our hernia series, in this episode Sam covers the anatomy of a hiatus hernia. What is it, how does it occur, what are its consequences and how do you treat them? 

Terms covered this week are hiatus hernias (and their types). The oesophageal hiatus of the diaphragm, the oesophageal smooth and striated muscles. Gastroesophageal reflux disease (GORD).   

In this episode let's prise out the anatomy of femoral hernias. What are they, where are they, and how do they differ from last week's topic of inguinal hernias? 

The main terms covered this week are femoral hernias and the femoral canal. The femoral arteries, nerves & veins. The fascia lata of the lower limb and its saphenous opening. 

This week let's explore the muscular canal found in the anterior wall of the lower abdomen, the inguinal canal. During our exploration let's apply this anatomy to a common medical condition, inguinal hernias. How do inguinal hernias occur & what is the difference between a direct & an indirect hernia? 

This week's terms are the anterolateral abdominal muscles (external & internal oblique muscles & the transversus abdominis muscle). The inguinal ligmaent & the deep & superficial inguinal rings. 

This week let's re-enter the nasal cavity & focus our attention on its blood supply. Why does the nose have such a significant blood supply? What vessels contribute to it? And what happens when it breaks? 

The terms covered this week are Little's area or Kiesselbach's plexus & Woodruff's plexus. The blood vessels with the mnemonic L.E.G.S, Labial (Superior), Ethmoids (anterior & posterior), Greater palatine & Sphenopalatine arteries. 

This week we explore the primary muscle of respiration that separates the thoracic & abdominal cavities. A muscle that was historically thought of as being the seat of the soul. In this podcast, we will dissect out the diaphragm's form, function, innervation, & blood supply. Whilst also explaining the origin of some of the terms we use to describe diaphragm-related structures.

The terms mentioned this week are the diaphragm and phrenic nerves. Costophrenic and costodiaphragmatic angles. The oesophageal hiatus and caval openings. Crura, the xiphisternum, skeletal muscle & somatic nerves.

In this 5-minute soundbite, we will cover the very basics of the tube that connects your nose, mouth and aerodigestive tracts. Location, subparts, composition, function and dysfunction. We will also cover sensory and motor innervation. 

Terms covered this week; The pharynx and its subparts. Nasopharynx, oropharynx and laryngopharynx (or hypopharynx). The constrictor muscles and mucosa. The vagus and glossopharyngeal nerves. 

This week we cover the nerves of the hand. The major motor components & the sensory distribution of each of the nerves that meander into the distal extremity of the upper limb. 

Terms covered in this episode are the median, radial & ulnar nerves. The flexor retinaculum. The thenar eminence & the lumbricals. 

Adorning the top of your spine are two unique vertebrae. Arguably the most important of the lot. Your Atlas & Axis or C1 & C2. In this episode, we explore greek inspired etymology, vertebral osteology & investigate why exactly cervical spinal injuries are so dangerous. By the end of this episode, you should be able to look through the 33 spinal bones all jumbled up & easily pick these two from the bunch. 

Terms covered this week; Atlas & axis. Spinous & transverse processes. Vertebral and transverse foramen. Vertebral body, lateral mass & articular facets.