Nutrient Distribution and the Circulatory System
The Distribution of Nutrients and the Circulatory System
The body needs to distribute nutrients and oxygen to cells and remove waste products like CO2, which will be eliminated by the excretory organs. This is the primary function of the circulatory system.
Components of the Circulatory System
- Blood: The means of transport for nutrients, oxygen, and waste.
- Blood Vessels: A network of tubes through which blood circulates.
- Heart: An organ that acts as a pump, making blood circulate.
Blood Vessels
- Arteries:
Ecosystem Dynamics and Nutrient Cycles
- Keystone species exert strong control on a community by their ecological roles, or niches.
- In contrast to dominant species, they are not usually abundant in a community.
- Ecosystem engineers (or “foundation species”) cause physical changes in the environment that affect community structure.
- Beaver dams can transform landscapes on a very large scale.
- The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or transformed.
- Energy enters an ecosystem as solar
Endocrine System: Hormones, Function, and Disorders
The Endocrine System
The endocrine system is distinct from the nervous system. It consists of a series of glands located throughout the body, called endocrine glands or glands of internal secretion. These glands secrete substances directly into the bloodstream. Endocrine glands are composed of specialized secretory cells that synthesize chemicals called hormones. Once produced, hormones are discharged into the blood and transported throughout the body via blood vessels. However, they only exert their
Read MoreHealth and Wellness: Occupational Illnesses, Nutrition, and Infections
Occupational Illnesses
Occupational illnesses are a serious problem for working people due to workplace-specific hazards. Sources of occupational illness include:
- Paint industries
- Cement industries
- Coal industries
- Pesticide industries
- Pharmaceutical industries
- Radioactive manufacturing industries
- Mineral extraction (heavy metal extraction)
Occupational Diseases
- Skin disorders: Allergic reactions, dermatitis, skin rashes, itching, skin cancer
- Respiratory disorders: Shortness of breath, chest pain, chest tightness,
Spinal Cord, Invertebrate & Vertebrate Hormones, and Nervous System
Spinal Cord
The spinal cord extends from the base of the brain to the second lumbar vertebra. The bone presents a very narrow cavity (ependyma). Inside the spinal cord, nerve cell bodies are clustered, bearing gray matter on its collaboration. Axons originate from the white matter surrounding the gray matter, forming longitudinal beam currents leading to the brain and sensory-motor currents from the brain to the muscles and glands. The gray matter is shaped like a butterfly, and their ends are called
Read MoreHuman Sensory System: Stimuli, Receptors, and Common Disorders
The Human Sensory System
A stimulus is a change in our environment or within us that we perceive and which provokes a response from our body. Coordination involves electrochemical processes and nerve impulses, producing high-speed electrochemical responses. Endocrine coordination involves glands discharging substances (hormones) into the blood when receiving nerve impulses or chemical information from the internal environment. Responses executed by muscles and glands are coordinated by the endocrine
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