Dissectible Me 5 minute anatomy

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 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 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? 

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?