Understanding Dermal Structures, Thermoregulation, and Skin Cancer
Dermal Accessory Structures
Arrector pili: Makes hair stand up on skin to generate heat when cold.
Hair follicle: Protects the scalp.
Sweat (eccrine) gland: Secretes water to the surface of the skin, causing cooling by evaporation.
Adipose tissue: Stores energy, cushions, and insulates the body.
Sebaceous gland: Secretes sebum to waterproof and lubricate the skin.
Sensory receptors: Respond to stimuli and transmit data.
Dermal papillae: Nourish the epidermal layer.
Blood vessels: Provide nutrients and help
Read MoreBlood Components and Blood Vessel Structure: An Overview
Blood Components
Blood is a specialized connective tissue that consists of several components, each performing crucial functions in the body. These components include plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets. Here’s a detailed look at each:
1. Blood Plasma
Structure: Plasma is a pale yellow liquid that constitutes about 55% of the total blood volume. It is a complex mixture primarily composed of water (~90%), which serves as a solvent for various dissolved substances.
Comprehensive Medical Care: Respiratory, Metabolic, Infectious, & Related Diseases
General Medicine: Respiratory Diseases, Metabolic Diseases, Infectious Diseases, Deficiency Diseases, Endocrine Disorders, Digestive System Diseases, & Lymphatic System Diseases
Introduction
General medicine covers a wide range of diseases & treatments, focusing on the diagnosis, prevention, & management of illnesses affecting different organ systems. Among the most common medical concerns R respiratory diseases, which affect the lungs & airways, often caused by infections. Infections
Read MoreUnderstanding Photoreceptors, Eye Anatomy, and Common Vision Problems
Photoreceptors and the Sense of Vision
Humans see in 3 dimensions and color. The eyes are the organs where light-sensitive photoreceptors are located, allowing us to see.
Anatomy of the Eye
The eye is formed by organs and appendages attached to it, including:
- Eyelids
- Eyelashes
- Eyebrows
- Lacrimal glands (produce tears, lubricate, moisten, and clean the eyeball; tears also have bactericidal properties)
Eyeball Structure
- Sclera: A thick protective sheath, also called the white of the eye. The anterior portion
Human Circulatory and Respiratory Systems: Functions & Anatomy
The Circulatory System
The circulatory system is responsible for transporting substances throughout the body. It consists of:
- A pump (the heart)
- A liquid (blood)
- A series of ducts (blood vessels)
The heart pumps blood throughout the body, delivering oxygen and nutrients to cells while collecting tissue debris and carbon dioxide.
Composition of Blood
Blood consists of:
- Plasma: A thick, yellowish liquid primarily composed of water and other substances.
- Blood cells:
- Red blood cells: Cells that have lost their
Cell Secretion: Mechanisms, Types, and Glandular Organization
Cell Secretion: An Overview
Cell secretion is the process by which cells synthesize and release specific substances into their internal or external environment to perform various functions. This process is primarily carried out by epithelial cells, which form glandular epithelia. However, non-epithelial cells can also secrete substances such as the interstitial extracellular matrix, histamine, or antibodies. Some cells produce materials for their own use, and organs like the gonads, bone marrow,
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