Volcanoes

Female Reproductive System
The female reproductive system make eggs and gives them a place to develop. Eggs are the cells of females and can be fertilized by sperm. When a egg and a sperm join a new life begins.
The eggs aremande in ovaries , the ovaries are the female reproductive organs that produce eggs and the hormoes estrogen and progesterone. The eggs begin to mature when a girl reachespuberty. One egg matures about every 28 days. The process by which the ovaries realse mature eggs is called ovulation.
Eggs are fertilized in the fallopian tubes that es a female reproductive organ that connects an ovary to the uterus.
Fertilized eggs develop in the uterus, wich is a muscular organ about the size of a fist.
The cérvix es the narrow base of the uterus, the lining of the uterusor the endometrium , the endometrium are tiny blood vessels , the blood vesels will carr away the baby wasteds. This Exchange happens via the placenta: a blood vesel rich tissue that forms ina mother uterus.

The vagina es the reproductive organ that conects the uterus to the outisde body. If a egg es not feritlized the endometrum break down, blood that bulit up in the uterus flow out of thebody through the vagina in a process called mesntruation.

The menstrual cycle is amonthly series of hormone controlled changes that mature an egg and prepare the uterus for pregnancy.

Muscular System

Muscular Sytem : The human body contains more than 650 individual muscles which are attached to the skeleton, which provides the pulling power for us to move around. The main job of themuscular system is to provide movement for the body. The muscular system consist of three different types of muscle tissues : skeletal, cardiac, smooth. Each of these different tissues has the ability to contract, which then allows body movements and functions. There are two types of muscles in the system and they are the involuntary muscles, and the voluntary muscles. The muscle in which we are allowto control by ourselves are called the voluntary muscles and the ones we can control are the involuntary muscles. The heart, or the cardiac muscle, is an example of involuntary muscle.

Muscles are made of , bundles or special cells called muscle fibers . Muscule fibers are made up of long paired strands of proteins. We have three types of muscles tissue in the body. Skeletal muscle, Striatedmuscle, is the tupe that you can move voluntary. Smooth muscles cause the involuntary movements of the eyelids.

Circulatory Sytem:
The circulatory system moves the blood all trhough the body. The heart and circulatory system (also called the cardiovascular system) make up the network that delivers blood to the body's tissues. With each heartbeat, blood is sent throughout our bodies, carryingoxygen and nutrients to all of our cells. The circulatory system is composed of the heart and blood vessels, including arteries, veins, and capillaries.
Blood: is a tissue that is made up of cells, fluid, and other substances, blood carries oxygen , carbon dioxde, and nutrients in the body through tubes called blood vessels. The heart is the organ that pumps the blood through the body.

Thehemeoglobin is the oxygen carrying pigment in the red bood cells of the blood.

The heart beats constantly blood that carries carbon dioxide returns form the body and enters the right atrium of the heart.
The atrium is a chamber of the heart that recives blood from the body.The atrium is pushed to a ventricle that is one of the two large muscular chambers that pump blood out of the heart.
Theheartbeat is a rhythmic contraction of the heart. Signals that begin a t the top of the heart cause the hartbeat.
A group of cells at the top of the right atrium are called the cardiac pacemaker starts a signal.

There are three types of vessels :
Arteries: are blood vessels that carry the blood away form the heart to all parts of the body.
Veins: are blood vessels that carry the blood form...