Hi Hilary, I'm heading into third year at Trinity and I can tell you a bit about the course so far.
In first year there are two semesters, well three including the exam season which is listed as a separate semester. Michaelmas semester runs from late September to mid December. And Hilary semester runs from mid January to mid April. There are reading weeks during each of the semesters. Throughout the first medical year you will study Biochemistry, Human Form and Function (Anatomy & Physiology) and Human Development, Behavioural Science and Ethics. To be more specific in Michaelmas biochem you will cover cell function, structure, metabolism. In anatomy you will study all of the musculoskeletal form from the neck down, in physiology you will study tissues, basic endocrine, basic blood, immunity, neuromuscular and some general principles. In HDBS you will study some basic behavioural sciences so theories of how we learn, how we develop, ethics. You sit exams then at the end of Michaelmas that are worth around 40% of your year grade. The HFF exam will cover all the anatomy and physio so far in one paper. You have to answer all questions on the paper with no choice The biochem paper is the same situation again, worth 40% but you have some choice on the paper. There are MCQs for a portion of physiology and biochem but the majority of the exams are essay based. There isn't an exam for HDBS for this semester though so breath a sigh of relief!
In Hilary semester you will study all thoracic, abdominal and pelvic anatomy. In physio you will study the related physiology of these systems to cardio physiology, respiratory physiology, renal, digestive etc... HDBS is basically just a continuation. Exams are conducted for this semester at the beginning of May and they take the same format as the Michaelmas exams, but are worth 60%. The HDBS paper is taken at this point too but it's not worth 100% of the module because you submit an essay, logbook and case study during the year that make up a fair chunk of the marks for it.
Also throughout the year there are weekly PBL sessions. Basically you are divided into smaller groups of up to 8 students and you meet for 2 hours twice a week to discuss a case study or a problem with a tutor together in a group. At the start of each session you will review the last problem covered the previous day. Then you move onto a new case and you will come up with learning goals for each problem that each person has to research and be prepared to discuss at the next meeting. This lasts throughout the year too but only for first year.
In second year the same story again. Except in the first semester you study head & neck anatomy, molecular medicine, clinical biochemistry and pharmacology. In the second semester you continue to study pharmacology and then neuroscience, microbiology and some basic pathology. Also during second year you have weekly clinical skills sessions every Tuesday in either St. James or Tallaght hospital. These are great lessons where you'll learn basic suturing, taking patient histories, putting in cannulas, drawing blood etc... You'll also get to be on a medical team in either the afternoon or the morning on certain weeks during their clinics or ward rounds and its great experience and a lot of fun.
Sorry for the word vomit and hope I didn't scare you too much. It's a great time. The social scene is excellent in Dublin too. There are a number of medical student societies that will organise nights out, mixers, trips away, quiz nights.... absolutely everything. Your classmates will be a very diverse and fun bunch too. The largest group in your class will be Irish kids coming through the Leaving Cert and CAO, then the next largest group will be North Americans, then Malaysian/East Asian students, mature students and then a mixed bag of people from everywhere you can imagine: the UK, France, Singapore. The great thing is everyone is very mixed up and the year as a whole will not be cliquey. All my experiences have been positive on this front with friendly people and everyone has time for each other and socialising. Welcome to Trinity and congratulations on entering medicine! You will have a great time here.