Exam 3 scores are up!

The scores for exam 3 are back already, and I just posted them on Canvas. You did really well, as always…here are the stats:

Total points: 46
Mean: 41.8
SD: 3
High score: 46
Low score: 30

It was REALLY REALLY nice to have all of you in class this semester 🙂 I’m happy I don’t have to say goodbye (I have you again for Pathology starting in May of this year, at which time you’ll be D2s!!).

Please feel free to stop up and visit any time (I’m in 16-206), whether it’s to check out your last exam, or just to talk. I’m still your (stand-in) mom, whether I have you in class or not!

Female repro slides 21 – 33

When I lectured on female reproductive histology on Tuesday, I began with slide 32, thinking that I was picking up where we left off the week before – but actually, we had stopped at slide 21! So here’s a summary of the important points on the slides we didn’t cover in lecture.

Slides 21-23 cover ovulation. At around day 12 of the menstrual cycle, estrogen (produced by the developing ovarian follicles) reaches its peak. This triggers release of massive amounts of LH (the “LH surge“) from the anterior pituitary. LH causes the Graafian follicle to move to the surface of the ovary and release its little oocyte into the world. This oocyte release is called ovulation, and it happens around the midpoint of the cycle (about day 14).

Slides 24-28 cover the corpus luteum. After it releases its oocyte, the Graafian follicle is called the corpus luteum. Under the influence of LH (we’re still in the LH surge), its granulosa and theca interna cells turn into granulosa lutein and theca lutein cells, respectively – and both cell types make estrogen and progesterone. The progesterone is particularly important because it stimulates growth of uterine glands, so that if the oocyte is fertilized, it has a nice cushy uterine lining to land on.

The corpus luteum hangs around for the remainder of the menstrual cycle, and if no fertilization occurs, it involutes (shrinks) and becomes a tiny white scar, called the corpus albicans. If fertilization does occur, the corpus luteum sticks around for the first trimester of the pregnancy, and then hangs it up and becomes the corpus albicans.

Slides 29-31 cover the endometrium. The uterus is composed of two layers:

  • Myometrium: smooth muscle, makes up the bulk of the uterus
  • Endometrium: glandular tissue, forms the lining of the uterus

The endometrial glands are divided into two zones:

  • Functionalis (at the top): glands in this region change during the menstrual cycle (they become longer and more tortuous during the second half of the cycle), and if no fertilization occurs, they become necrotic and are sloughed off during menstruation.
  • Basalis (at the bottom): glands in this region don’t change during the menstrual cycle; their job is to replenish the functionalis after menstruation.

That’s about it! Let me know if you have questions.

Diagram of what happens to female germ cells

Here’s an interactive drawing I made that shows what happens to female germ cells over time. I think it’s kind of helpful to see the numbers (and stages) of the germ cells mapped out by age – it gives you a visual sense of what happens throughout life.

I can’t post the drawing on our website because of wordpress limitations – but I was able to post it on my Pathology Student website (so when you click on the link, you’ll wind up on that website).

Respiratory tree drawings

Thought I’d share a drawing with you guys in case it helps. It shows how the wall of the respiratory passageways changes as you go from bronchi to alveoli. There are three versions, so you can use it fully labeled, partially labeled, or unlabeled, however it suits you best. Let me know if you find it useful – if so, I’ll make more 🙂

Unlabeled:

Labeled with passageways only:

Fully labeled:

 

 

Exam scores are up!

Exam scores are back, finally! I don’t know what the holdup was – but they’re up now.

You guys did REALLY WELL. Here’s some stats, before adding a point (see below):

  • Mean: 46 (out of 49)
  • SD: 2.47
  • High score: 49
  • Low score: 34

All the questions except one performed really well (between 90-100% of the class got them right). The question that gave you guys trouble was this one:

Blood cells leave the marrow, circulate in the blood for a certain period of time, and eventually are removed from the blood. The cells that spend the longest amount of time in the blood are _____, and the cells that are in the blood for the shortest period of time are ______.

A. Platelets; neutrophils
B. Erythrocytes; platelets
C. Neutrophils; erythrocytes
D. Neutrophils; platelets
E. Erythrocytes; neutrophils

The correct answer was E (erythrocytes last about 4 months in the blood, platelets last around a week, and neutrophils are only in the blood a few hours before they exit into tissues). The class was about split between B and E, and I’m assuming it’s because I didn’t teach the point well enough.

I’m adding a point to everyone’s score for this question – so if you got them all right, you’ll see that your score is now 50/49.