Explorez tous les épisodes du podcast Dissectible Me 5 minute anatomy

Ligaments and tendons are similar but different. Tendons transmit forces from muscles to bones, and ligaments support joints and tie them together. Some are stretchy, some are not. Ligaments give proprioceptive information about joint position and both heal very slowly because of a poor blood supply. And what about peritoneal ligaments? Are they the same thing? 

If a dermatome is a strip of skin innervated by branches of a single spinal nerve root, a myotome is a block of muscle innervated by branches of a single spinal nerve root. But multiple myotomes come together to form the skeletal muscles that we recognise. So how can we use the knowledge of myotomes to test nerve function? 

A dermatome is a strip of skin innervated by a single spinal nerve. A dermatome is also a part of the somite that will form the dermis of the skin. How is understanding this anatomy useful? 

What are the differences between grey matter and white matter in the nervous system, anatomically speaking? 

Fascia is classically described as a series of sheets of connective tissue wrapping the body and compartments within it. It holds us together and gives us shape. But what is fascia? 

The embryonic period in humans is the first 8 weeks after fertilisation. What happens during the embryonic period and why is it different to the foetal period?

The anatomy of spinal nerves is rather neat, but can also be confusing. Let me talk about the dorsal and ventral roots, sensory and motor neurones, the spinal nerve and its posterior and anterior rami. 

What anatomy would I include if I only had 5 minutes to talk about forearm? I think I'd group the muscles, movements and nerves together to better understand what movements would be affected by a nerve injury. 

The autonomic nervous system innervates the sino-atrial node and controls the rate of contraction of the heart. What other effects do sympathetic and parasympathetic nerves have on the heart? I can think of two more. 

There are a few anatomy landmarks of the abdomen, some of them bony, that we can palpate and use to understand what structures lie deep to the skin here. We can also use them to divide up the abdomen into either 4 imaginary quadrants or 6 regions to help use describe signs or symptoms to others. 

Let's introduce the anatomy of the airway very briefly by starting at the nose and the mouth and working our way down to the alveoli. 

The sternal angle is an important surface anatomy landmark of the chest, deep to which some major anatomical structures lie. 

Synovial joints are specialised for movement. The shapes of the articulating surfaces define what movements are allowed, and we can anatomically classify synovial joints by these shapes and by these movements. We have hinge, ball and socket, plane, saddle and condyloid synovial joints. 

Fibrous joints, cartilaginous joints and synovial joints. We can define them by what they are made of, and in turn, what they are made of tells us what movements they might allow. 

The biggest bone in the body. What pertinent anatomical features should you be aware of?

What would I include if I only had 5 minutes to talk about the functional anatomy of the ovary? 

What nerves run through the inguinal canal and are they at risk of injury during an inguinal hernia repair? 

The hippocampus is part of the limbic system in the brain. What does that mean? What does it do? Where is it? In 5 minutes(ish)?

The oesophagus is a muscular tube linking the pharynx to the stomach. The muscles of the face and pharynx are skeletal and under somatic control, whereas the muscles of the stomach are smooth and autonomic. Where does this change happen? 

Why do we have three tiny bones in each ear? 

When we talk about "stroke" or a cerebrovascular event we're describing reduced blood flow to a region of the brain. What are the different types and how does this relate to our functional anatomical knowledge of the brain, brainstem and blood supply? 

The trochlear nerve (CN IV) has the single task of innervating the superior oblique muscle. Unfortunately the actions of this muscle on the eye are a little awkward to understand, so how is the eye affected if the trochlear nerve is injured?

The abducens nerve is one of those lovely cranial nerves that only does one thing, making learning it nice and easy. But what happens when it is injured, and how can that knowledge be helpful? 

What happens to the eye when the oculomotor nerve is injured or compressed? How can these signs and symptoms inform us about what might be happening inside the cranial cavity? 

The pupillary light reflex can let you test the optic nerve, midbrain and oculomotor nerve just by shining a light into someone's eye. Let's talk about the anatomy and how this works. 

Those folds and lumps of the external ear have all got names. Let's feel the concha, tragus, antitragus, helix, antihelix and opening of the external acoustic meatus together. 

The acoustic reflex is a mechanism that protects the ear from loud sounds. It is also called the stapedial reflex, middle-ear-muscle reflex and auditory reflex, among other names. What is the neuroanatomical pathway of this reflex, how does it work, how are the smallest bone and muscle in the body involved, and how can it be useful in determining problems with hearing?

The hypothalamus, as its name suggests, lies in the brain inferior and anterior to the thalamus. It is a central structure in modulating many autonomic functions and homeostasis. What does that mean, and what does it do?

What do we mean by the neck of the femur and why do we worry (more than usual) about a fracture here? 

The blood brain barrier describes how the endothelial cells of the capillaries in the brain are tightly stuck together by tight junctions, wrapped in the feet of astrocytes and lined by a basement lamina. This stops most molecules from moving between the blood and the brain through any gaps. Instead, transporters are needed to transport molecules across the endothelial cells. Why does this happen in the brain? How does ethanol get to the brain? 

The brain has spaces inside it, interconnected and filled with cerebrospinal fluid. This fluid is continually produced here and flows from chamber to chamber, sometimes through narrow passageways, until it leaves to surround the brain and spinal cord. 

Cerebrospinal fluid surrounds the brain, brainstem and spinal cord, it fills spaces within them, is continually produced and drained away, but why? 

The muscles that flex and extend the elbow joint. Biceps brachii, brachialis, triceps brachii, anconeus and brachioradialis. What they attach to, how they move the bones and the nerves that innervate them in 5 minutes(ish). 

The term "brain death" can be used to refer to irreparable damage of the brainstem or cerebrum. By considering the differing functional anatomy of the brainstem and the cerebrum we can more clearly understand what type of injury is being referred to when this term is used in relation to a particular person. Functional neuroanatomy also helps us understand why movement of the eyes, groaning, and even movement of the limbs can still occur in some cases of brain death. 

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 support the uterus. 

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 of these foetal adaptations must close with the first breath and the activation of the lungs. 

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.