An Overview of Human Tissues
1. Types of Tissues
Tissues are distinct materials in animals and plants, made of specialized cells and their products. There are four main types:
1.1 Epithelial Tissue
These tissues cover body surfaces, line passageways and cavities, and form glands.
1.2 Connective Tissue
Found throughout the body, connective tissues primarily connect and support other structures.
1.3 Muscle Tissue
Located in skeletal muscles, hollow organs, the heart, and places like the iris, muscle tissue enables movement.
1.4 Nervous
Read MoreUnderstanding Infectious Diseases: Causes, Transmission & Antibiotic Resistance
Bacterial Diseases
Cholera – Vibrio cholerae
To reach their site of action in the small intestine, Vibrio cholerae bacteria must first pass through the stomach. If the stomach’s contents are sufficiently acidic (pH less than 4.5), the bacteria are unlikely to survive. However, if they reach the small intestine, they multiply and secrete a toxin called choleragen. This toxin disrupts the functions of the epithelium lining the intestine, causing salts and water to leave the blood. This leads to severe
Read MoreThe Human Brain: Structure, Function, and Clinical Significance
The Hemispheres of the Cerebrum
Left and Right Hemispheres
The cerebrum is divided into two hemispheres, the left and right hemispheres.
Neural Cortex
The gray matter on the surface of the cerebrum is called the neural cortex.
Functions of the Cerebrum
True: Conscious thoughts, sensation, intellect, intelligence, rationalization, and complex movement all originate in the cerebrum.
True: The highest level of information processing occurs in the cerebrum.
True: The cerebrum controls higher mental functions.
Read MoreHormonal Regulation, Renal Physiology, and Reproductive Health: An In-Depth Guide
Hormonal Regulation of Renal Sodium Reabsorption
Question: Mention two hormones that would increase renal Na+ reabsorption. What are their effects and mechanisms of action? Which segments of the renal tubules do they affect?
Answer:
Two hormones that are secreted to increase Na+ reabsorption are:
1. Aldosterone
Aldosterone stimulates Na+ reabsorption in principal cells of the distal convoluted tubule (DCT) and cortical collecting duct (CCD). It increases Na+ reabsorption in exchange for K+ secretion.
Read MoreHuman Biology and Nutrition
Sense Organs
Hearing
Hearing consists of three parts: the external ear, middle ear, and inner ear.
External Ear
This is formed by the pinna, the ear canal, and the eardrum.
- It is in charge of collecting and transmitting sound waves into the middle ear.
- The ear canal contains small hairs and wax-producing glands that are responsible for protecting the inside.
- The eardrum is a membrane that separates the outer ear and middle ear.
Middle Ear
This is formed by the tympanic cavity, which contains three holes.
Read MoreUnderstanding Cells and Tissues: A Comprehensive Overview
Chapter 3: Exploring the Cell
What is a Cell?
The cell is the fundamental structural and functional unit of the body. It is the smallest living unit.
Three Main Regions of a Cell
- Cell Membrane: The outer boundary of the cell.
- Cytoplasm: Includes the cytosol (watery fluid) and organelles.
- Nucleus: The control center of the cell.
Structure of the Cell Membrane
The cell membrane is a phospholipid bilayer, composed of two layers of phospholipids. Embedded within this bilayer are proteins and cholesterol. Carbohydrates
Read More