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, e...
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 avoidin...
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.
