system
Given the following post, respond as if you're commenting on Reddit:
human
Why are your ears, nose and throat all connected?
gpt
Because once upon a time your ancestors were fishes.

I'll do this one organ at a time.

**Throat**

Your throat is derived from a structure called the **pharynx**.  The pharynx in fishes is essentially the tube between the mouth and the entrance to the esophagus.  This tube, in fishes, has holes in the side.  These holes are called **pharyngeal slits.**  In most fishes, there are thin, highly vascularized filaments inside these slits, and the pharynx is used to pump water over these filaments.  We call this sort of structure a "gill."  In humans, the pharynx is the back part of the throat up to the epiglottis.

**Nose**

The nose develops initially from a pocket that forms in the anterior head of an embryo called the **nasal capsule**.  This capsule contains all the sensory receptors of the nose and is tightly integrated with the anterior brain via the olfactory nerve.

In early fishes, the nasal capsule is just a pocket in the side of the snout. Later fishes have a flow-through system, with an anterior and a posterior nostril.  When you get to the lineage that leads to tetrapods, the posterior nostril slips inside the mouth, and the flow-through nasal capsule not only becomes a means of smelling things, but a means of getting water into the mouth, where it could then pass over the gills. We call this internal nostril a **choana**. The choana later becomes a means of getting air into the pharynx for passage into the lungs as our ancestors start moving onto land.  In most reptiles and amphibians, the choana is perforates the bony palate right behind where your canine tooth is.

Now, in mammals, what we see is that there is what's called a "secondary palate" which is a plate of bone that forms between the oral cavity and the choana to create an actual nasal cavity, which is what we have.  You still have a passageway between the nasal cavity and the pharynx, but it's further back now. This, among other things, allows you to breathe while chewing and to avoid getting food wedged up your nose all the time.

**Ears**

There are three parts to your ear: the inner ear, the middle ear, and the outer ear.  The inner ear includes a series of canals associated with balance (**semicircular canals**) and a series of tubes and membranes that transduce sound waves into firing of nerves.  The outer ear includes the rubbery flap of ear on the outside of your head (the **pinna**) as well as the ear canal.  The middle ear contains a series of bones (**auditory ossicles**) that connect the eardrum to the inner ear.  Of these, the middle ear is the only part of the ear directly connected to the throat.

Now, there are three bones in the middle ear; the **malleus**, the **incus**, and the **stapes**.  You may know these as the hammer, anvil, and stirrup.  Fishes have these same bones, but they don't use them for hearing.  They're part of their jaws.  The malleus is a bone from the lower jaw called the **articular**.  The incus is a bone from the upper jaw called the **quadrate**.  The stapes is a bone that braces the upper jaw against the skull, called the **hyomandibula**.  The upper and lower jaws occurs between the quadrate and articular. There is a passage that runs past the hyomandibula called the **spiracle**, which is essentially a specialized pharyngeal slit.  It was used to modulate water flow across the gills.

Now, as our ancestors crawled out of water, they started using these bones in their jaws to carry sound to the inner ear.  The articulation between the quadrate and the articular is still the primary jaw joint in most amphibians and reptiles, for example.  In mammals, though, a second jaw joint forms called the **temporomandibular joint** (TMJ) and the quadrate/incus and articular/malleus completely separate from the lower jaw.  The spiracle slit never opens, leaving a thin membrane across the surface of the spiracular opening.  This membrane is the eardrum or **tympanic membrane**.  What's left of the spiracle now is the middle ear and the tube that connects the middle ear to the throat, called the **eustachian tube**.

So, in other words, the reason these organs are all connected is because of a combination of how these organs develop and the evolutionary history of these organs in our distant fishy ancestors.

Hope this helps.

**tl;dr: because once upon a time our ancestors were fish and these organs did very different things**