Endocrine System

Today, in our biology class we learnt about the endocrine system. We had to do some activities and we did it in groups. I was with Cata Rela and Tomi Borda. Here is our work 🙂

  1. Hormones are chemical substances that help to regulate processes in the body.
  2. Glands that secrete hormones:

 

3. Effects of Adrenaline: Prepares body for action – ‘fight or flight’.

Adrenaline is the hormone secreted in ‘fight or flight’ situations. It’s secreted when you are frightened, excited or keyed up. Adrenaline effects could be: increased breathing, increased pulse rate, widened pupils, increased blood glucose concentration and increased pulse rate. These people are secreting adrenaline since they are in an exciting situation in which they have to act quickly.

 

The Eye as a Sense Organ

In Biology we are studying the eye as a sense organ. Male gave us some activities to do in pairs. I was with Cata.

1. Structure of the eye.

2.  Functions of the eye structures.

3. Booklet page 9 exercise 3. 

4. Animation showing how the eye works.  

5. Booklet page 9 exercise 2: The cornea bends or refracts the light rays for the lens to bend and focus them on the fovea (if there is a bright light, on cones) or throughout the retina (if there is dim light, on rods).

6. VIDEO explaining the pupil reflex.

-stimulus: a bright light. >> receptor: cones >> coordinator: brain >> effector: radial and circular muscles >> effect: circular muscles contract while radium relax >> response: the pupil constricts.

-stimulus: a dim light. >> receptor: rods >> coordinator: brain >> effector: radial and circular muscles >> effect: circular muscles relax while radium contract >> response: the pupil gets dilated.

CIRCULAR MUSCLE vs RADIUM MUSCLE: Antagonistic muscles

7. Booklet page 9 exercise 1c: In the dark room light is focused all over the retina, where the rodes are. Rodes are stimulated the, but rodes are of black and white vision only. So Jasmin seed only shapes, not colours.

8. Animations to learn how the eye focuses on a nearby and a distant object.

9. Booklet page 9 exercise 2b: If a close object is focused, the light rays coming will be diverging so they will need a lot of bending. The cornea will bend them and focus them on the lens and the lens will need to be thick so it bends more. The ciliary muscles contract, the suspensory ligaments go slack and the lens becomes shorter and fatter.

Booklet page 10 exercise 4a: Lens and cornea

10.  Booklet page 10 exercise 5: 

a. light receptors bring out electrical impulses.

b.

c.

d.