Circulatory, Nervous & Reproductive Systems: Key Functions and Terms

Circulatory System

1. Define the circulatory system

The circulatory system is constituted by the heart, blood, and blood vessels by which blood is distributed throughout the body.

2. What is blood plasma?

Plasma is a yellowish liquid composed of about 91% water and the remaining ~9% consisting of salts, proteins, lipids, glucose, and urea.

3. Origin and types of blood cells

Blood cells originate in the bone marrow. The main types are:

• Red blood cells (erythrocytes)
• White blood cells (leukocytes)
• Platelets (thrombocytes)

4. Anemia

The main symptoms are fatigue and loss of vitality; these are direct consequences of decreased oxygen delivery to the body's cells. The most common form is iron-deficiency anemia. It is usually corrected by a sufficient and balanced diet rich in iron-containing foods.

5. Define arteries, veins and heart chambers

Arteries: Conduits that carry blood from the heart to the organs.

Veins: Vessels that carry blood from the organs back to the heart.

Atria (auricles): The superior chambers where blood enters the heart.

Ventricles: The inferior chambers that pump blood from the heart into the arteries.

6. Cardiac cycle

Atrial systole: The atria contract and push blood into the ventricles.

Ventricular systole: The ventricles contract, forcing blood into the arteries by opening the pulmonary and aortic valves.

Diastole: The heart muscle relaxes; valves prevent arterial blood from returning to the heart.

Nervous System and Coordination

1. What function does the peripheral nervous system perform?

Its function is to transmit sensory and motor information to and from the central nervous system, and to deliver commands from the central nervous system to the organs and tissues responsible for implementing them.

2. Cerebrum and cerebellum

Cerebrum: Divided into two hemispheres, the cerebral cortex receives sensory information and prepares responses.

Cerebellum: Located below the cerebrum, it coordinates movements (such as walking or manipulating objects) and helps maintain balance.

3. What is the structure of a neuron?

A neuron is distinguished into several parts: the cell body (soma), dendrites, and the axon. The axon may be covered by myelin, and nerves are bundles of these nerve fibers.

4. Alzheimer's

Alzheimer's disease is a degenerative disorder caused by the destruction of nerve tissue in the cerebral cortex, leading to progressive memory loss and cognitive decline.

5. What types of glands do we have?

Endocrine glands: Produce and release substances called hormones into the blood (examples: pituitary, thyroid).

Exocrine glands: Secrete their products outside the body or into body cavities (examples: sweat glands, salivary glands, and secretions from the liver such as bile into ducts).

Human Reproduction

1. What are gametes?

Gametes are specialized cells responsible for transmitting hereditary information. The male gamete is the sperm and the female gamete is the ova (egg).