Respiratory, Muscular, Skeletal Systems

Students are learning about breathing and how the respiratory system works. We've talked about it briefly already when we discussed the circulatory system because they work so closely together. They will need to know the path oxygen takes as it enters the body as well as the functions of each structure.



The muscular system helps with all daily movements: relaxing, contracting, and providing the force for movement. We have voluntary and involuntary muscles. Voluntary are the ones we control, but involuntary we cannot control consciously. Muscles always pull, and when one muscle of a pair contracts, the other relaxes. Students will NOT have to name any specific muscles.


The skeletal system includes all the bones in our body and has five major functions:

1. give shape and support body
2. protect organs
3. help major muscles move
4. form blood cells in the marrow
5. store calcium and phosphorus

Joints are a very important part of the skeletal system. A joint is shere two or more bones come together. There are two kinds of joints: immovable and movable. The immovable joints are the ones in your skull and pelvis because they don't move. There are 4 kinds of movable joints: ball-and-socket, gliding, hinge, and pivot. A pivot joint is when one bone rotates in a ring of another bone that doesn't move, like turning your head. A ball-and-socket joint consists of a bone with a rounded end that fits into a cavity in another bone, like your shoulders and hips. A hinge joint has a back and forth movement like a door hinge. An example of this is the knee, it only moves one way. The last joint is a gliding joint. These joints allow one bone to slide over another, like in your wrists, ankles, and vertebrae.

Body Systems

We are working on the 11 body systems until Spring Break.

• Reproductive (Feb 22-26)
• Circulatory (Feb 22-26)
• Endocrine (Feb 22-26)
• Respiratory (Feb 29- March 4)
• Muscular (Feb 29- March 4)
• Skeletal (Feb 29- March 4)
• Digestive (March 7-11)
• Integumentary (March 7-11)
• Excretory (March 7-11)
• Nervous (March 14-18)
• Immune (March 14-18)

Embryology

Students will need to about the development of an embryo. They got to see some interesting stages in the development when we looked at microslides last week.

Look at our sheet on embryology for info on:

• Morula
• Blastula
• Gastrula: endoderm, ectoderm, mesoderm

Chicken Embryos

***Dissect a poultry egg and analyze the development of embryos***

Chicken Embryo Development

Students must know the different parts of the chicken egg and what their job is!

Shell-protects the embryo/gives air/moisture for the chick with it's pores
Shell membrane- protects the embryo from bacteria, outside elements
Albumen-(white) protects embryo/provides embryo with water
Chalazae-Protects the embryo from vibrations and holds yolk in place (like a seatbelt)
Yolk-Provides food for embryo(vitamins, minerals, fat)
Air Cell-A sac of air at the bottom of the shell
Germ spot- the white spot on the yolk where an embryo starts to grow

Cells

This week we have been discussing cells. We looked at the difference between plant and animal cells. Students should note animal cells DO NOT have cell walls, central vacuoles, and chloroplasts.

We talked about the cell parts and what they do, particularly that nucleus is the largest of the organelles and contains the chromatin (DNA).

We have been learning about sex cells, also called gametes, in the human body. Each sex cell carries 23 chrosomes in its nucleus. This is the genetic material that will be needed to make a new individual with a total of 46 chromosomes (what most people have).
Sperm are the sex cells made by the male reproductive organ.

Eggs (ova) are the sex cells made by the female reproductive organ.

We are learning about the difference in sexual and asexual reproduction. Sexual reproduction is when two sex cells join to produce a new individual. It is called fertilization the moment the sperm and egg cell meet. Asexual reproduction is when one cell makes more cells that are genetically identical to it. Types of asexual reproduction are: budding, regeneration, and fission.

Our body cells have similarities and differences. The differences are the size, shape, and function. The similarities are their needs, waste, and parts. Every cell needs water, food, and oxygen to survive. These are carried to the cells all over the body by our arteries. All cells produce waste from the food, water, and oxgen called urea and carbon dioxide. This waste is carried away from the cells by veins. The main parts of a cell are also similar. All cells have a nucleus, cytoplasm, cell membranes, and organelles.