Human Body Defenses and Disease Classifications
Natural Body Defenses
Constitutive Defenses
- Genetic Resistance: Our system lacks the specific receptors necessary for the entry of certain microorganisms.
- Anatomical Barriers: Prevent the entry of pathogenic agents into the body.
- Inflammatory Response: An increase in temperature induces an immune response, phagocytosis, and vasodilation, facilitating the arrival of defenses.
- Phagocytic Defense: Phagocytes destroy pathogens.
Induced Defenses
These are specific defense responses triggered by the presence
Read MoreUnderstanding Iron Metabolism, Hemostasis, and Blood Clotting
Iron Metabolism (Fe)
Iron is constantly lost through urine, approximately 1 mg/day. Iron consumption can be in ferrous or ferric form. Only about 10% of consumed iron is absorbed, necessitating a daily intake of 10 mg. This minimum iron intake should be doubled or tripled during pregnancy or menstruation.
Total iron reserves in the body are between 4-5 grams. 70-75% of this iron is in the form of hemoglobin, 15-20% as transferrin, 5% as myoglobin, and 1% in various other forms.
Iron is consumed in
Read MoreCellular Transport, Metabolism, Photosynthesis & Respiration
Cellular Energy and Material Exchange Processes
Cellular Transport
Cellular transport refers to the exchange of substances between the cell interior and the exterior environment through the plasma membrane, or the movement of molecules within the cell.
Metabolism: Catabolism and Anabolism
Catabolism
Catabolism is the part of metabolism involving the transformation of complex biomolecules into simpler molecules. This process releases chemical energy, which is stored in the phosphate bonds of ATP molecules.
Read MoreProkaryotic and Eukaryotic Cells: Structure, Function, and Medical Significance
Prokaryotic and Eukaryotic Cells
Endospore Formation
- Spores formed many millions of years ago (mya) are still viable.
- Looking for these is what that phase contrast microscope was for.
Endospore Formation
- Stimuli for sporulation
- Depletion of nutrients
- Chemical signals
- Are there a lot of me around?
- Only a subset sporulate → rest wait it out (or try)
- Vegetative cell → sporangium
- Sporangium → endospore
- Hardiest of all life forms
- Withstand extremes in:
- heat, drying, freezing, radiation, and chemicals
- Regulated
- Withstand extremes in:
Human Sexual Reproduction: Stages, Fertilization, and Development
Human Sexual Reproduction
In sexual reproduction, two cells unite (sperm and egg), each from one individual of the opposite sex, to form a zygote. The zygote develops and produces an offspring that is genetically different from the parents.
Puberty and Adolescence
Puberty: The acquisition of sexual maturity during adolescence.
- Primary Sexual Characteristics: Reproductive organs.
- Secondary Sexual Characteristics: Hair, voice changes, etc.
Adolescence: The stage from approximately 9 to 18 years of age,
Read MoreUnderstanding the Human Digestive System: Organs, Glands, and Processes
The Human Digestive System: An Overview
The digestive system is a complex network of organs working together to break down food and absorb nutrients. It consists of the following:
- Mouth: Where digestion begins with saliva.
- Pharynx: The throat, a passageway for food and air.
- Esophagus: A muscular tube that carries food to the stomach.
- Stomach: An organ that churns food and mixes it with gastric juices.
- Small Intestine: The primary site for nutrient absorption.
- Large Intestine: Absorbs water and forms stool.