Human Body Systems: Nerves, Senses, and Hormones
The Nervous System and Environmental Interaction
The nervous system interacts with both internal and external environments. This interaction allows the body to detect changes and provides appropriate responses to them. Sensory receptors are specialized cells that detect these changes. A detectable change is known as a stimulus.
The Path of a Nerve Impulse
The journey of a nerve impulse from stimulus to response follows a specific sequence:
- A stimulus occurs.
- Sensory receptors detect the stimulus.
- Sensory
Human Respiratory and Digestive Systems & Illnesses
Human Respiratory and Digestive Systems
The respiratory system exchanges gases with the external environment. It takes oxygen (O₂) from the air and transfers it to the bloodstream, while taking carbon dioxide (CO₂) from the blood and expelling it from the body.
The Respiratory System
Components of the Respiratory Tract
- Nasal passages
- Pharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
These tubes carry air from outside the body into the lungs and vice versa.
The Lungs
Spongy organs located in the rib cage and separated
Read MoreAnimal Digestive System Parts and Function
Digestive Tract Parts and Function
The digestive tract consists of:
The Mouth: Initial Digestion
The mouth is the entry zone for food. It performs two types of digestion:
- Mechanical Digestion: This is the chewing done by teeth. Depending on the animal, the dentition is different and adapts to the type of feeding. For example, birds have no teeth but use their beak, tongue, and hard palate. Food is crushed in the gizzard. Carnivores have very developed canine teeth, while herbivores do not have them
Fundamental Biological Processes
Metabolic Phases
Phase Degraded (Catabolism)
A set of reactions aimed at obtaining energy and precursor molecules. The degradative and catabolic processes are energy-producing chemical reactions and are exergonic. The major catabolic pathways:
- Glycolysis: The pathway that degrades glucose to produce pyruvate.
- β-Oxidation: A set of reactions that occur in the oxidation of fatty acids to give rise to acetyl coenzyme A.
- Transamination and Deamination: The set of processes that take place in amino acid
Key Concepts in Health and Disease
Types of Diseases
Diseases can be categorized in various ways:
- Infectious and Parasitic Diseases: cholera, influenza.
- Tumors: benign tumors, cancer.
- Hemic and Immune System Diseases: anemia, coagulopathy.
- Mental and Behavioral Disorders: depression, intellectual disability.
- Nervous System Diseases: meningitis, neuropathies.
- Diseases of the Sense Organs: blindness, otitis.
- Respiratory System Diseases: bronchitis, asthma.
- Digestive System Diseases: caries, appendicitis.
- Skin Diseases: dermatitis, alopecia.
- Congenital
Understanding Disease and Evolutionary Biology
Disease Concepts and Control
Re-emerging and Emerging Diseases
Re-emerging diseases: Caused by germs in an unknown state that may have been hidden for a long time and then appear suddenly, like Ebola or tuberculosis.
Emerging diseases: Mutations may occur. Includes past illnesses that remain with us, such as cholera, tuberculosis, dengue, malaria.
Infectious Agents
Infectious agents: Pathogenic microorganisms that cause diseases. They are those that invade our body, called the host, and reproduce within
Read More