MHC, Immunity, and Immune Response: A Comprehensive Look
Major Histocompatibility Complex (MHC)
MHC proteins are located in the plasma membrane of cells. They distinguish between foreign entities and the body’s own cells. This group of genes has high variability, making it highly improbable that two individuals will have the same set of proteins.
There are two types:
- MHC Class I: Present in all cells of the organism. Involved in antigen presentation to cytotoxic T cells (MHC Class I).
- MHC Class II: Present only in antigen-presenting cells (APCs) of the immune
Essential Concepts in Biology: A Comprehensive Review
Essential Concepts in Biology
What is Science?
Science is a body of knowledge and a process for generating that knowledge.The Scientific Method
The steps include:- Observations
- Hypothesis: “If… then…”
- Predictions
- Test (Observations and Experiments)
Observation Defined
A description, measurement, or record of any object or scientific phenomenon.Hypothesis: Definition and Testing
An informed, logical, and plausible explanation for observations of the natural world. It should be possible to show that
Understanding the Central Nervous System: Structure and Function
Understanding the Central Nervous System
The central nervous system (CNS) is responsible for analyzing sensory information, storing it, and initiating specific actions.
Spinal Cord
The spinal cord processes spinal reflexes. It conducts sensory nerve impulses to the brain and motor nerve impulses from the brain to effectors.
Brain Stem
Medulla Oblongata
The medulla oblongata contains the cardiovascular center (which monitors heart rate, force, and blood vessel diameter) and the respiratory center.
Pons
The
Read MoreAnimal and Plant Nutrition: Processes and Systems
Nutrition encompasses the substances that living organisms use and convert into energy and matter through their own processes. These substances, found in living foods, are composed of single units.
Nutrients
Nutrients are direct and simple substances that reach the cells.
Animal Nutrition
Digestive Processes
This involves breaking down food substances into simpler forms that the body can use and transport to cells via the blood.
Gas Exchange
This is the process of taking in oxygen for metabolism and expelling
Read MorePeptic Ulcer Disease: Causes, Symptoms, and Treatment
Peptic Ulcer Disease
Peptic ulcer disease corresponds to the focal loss of tissue in segments of the digestive tract mucosa that are in contact with HCl and pepsin. It involves at least the entire thickness of the mucosa and submucosa. Duodenal ulcers are 3 to 4 times more common than gastric ulcers.
Erosion (Acute Ulcer): Affects the mucosa and submucosa. Aspirin use can cause multiple and superficial erosions with minimal inflammation or fibrosis. Stress can also be a factor. These ulcers typically
Read MoreSpermatogenesis and Oogenesis: Key Facts
Key Facts About Spermatogenesis and Oogenesis
Spermatogenesis:
- The stage of spermatogenesis that lasts about one day is meiosis.
- Sperm is stored and continues its journey in the epididymis.
- Vasectomy is performed on the vas deferens.
- Characteristics of the seminal glands:
- They are organs that secrete 60% of the volume of semen.
- Secretion of fructose and citric acid.
- Secretion of coagulating proteins.
- Characteristics of the prostate gland:
- It secretes 20% of the volume of semen.
- Secretion of clotting proteins.