The Immune System

The immune system is really complicated, we know. There's a lot to keep track of: how cells kill invaders, how antibodies work in the adaptive immune system, all those signaling chemicals. At least there is one simple part of it though, and that's remembering where B and T cells live. Heck, their names even spell it out for you: B cells belong in the bone marrow. T cells travel to the thymus.

The Endocrine System

Imagine you're playing Truth-or-Dare. Because you don't want to kiss anyone's grandmother, (grandmothers are playing this game with you, it's a weird scene) you opt for the relatively safe "Truth."The truth question is to list all the endocrine glands. Lucky you. You begin to panic, but then smile and breathe a sigh of relief. You remember the mnemonic from Shmoop: Hey! Princess Peach got pink tutus again! (Have you ever looked at her wardrobe? Not exactly bursting with variety.) You're able to recite "Hypothalamus, pituitary, pineal, gonads, pancreas, thyroid, adrenals."

The Nervous System

Remembering what type of peripheral nervous system kicks in during various situations can get pretty confusing, but it's an important concept to know and impacts a lot of other issues in the nervous system. One way to help keep them straight is with this handy bit of mental organization. When you are feeling sympathetic to another person, you have heightened emotions (you're sad because they're sad, angry because they're angry, etc.). The sympathetic system also leaps into action when emotions are running high—you'd better believe you'll be feeling a range of feelings when that angry rhino comes bursting through the front door.

Fitting It All Together

Even though these three systems interact with each other all the time, it's important to keep their modes of communication straight. To help you out, we've concocted a catchy mnemonic: Every hungry nun needs ice cream. There will be no forgetting the pairs between: endocrine-hormones, nervous-neurotransmitters, immune-cytokines.