Human Respiration and the Circulatory System
Respiration
Respiration is the process by which air containing oxygen enters our body, and air rich in carbon dioxide is expelled. A living being can survive for several hours without eating, sleeping, or drinking water, but cannot stop breathing for more than three minutes. This fact highlights the importance of breathing for our lives.
Composition of Air
- Nitrogen (N2): 78.084%
- Oxygen (O2): 20.946%
- Argon (Ar): 0.9340%
- Carbon dioxide (CO2): 0.039%
- Neon (Ne): 0.001818%
- Helium (He): 0.000524%
- Inter alia
Respiratory
Read MoreHuman Biology: Digestion, Respiration, Circulation, and Excretion
Digestive Function
Ingestion: Intake of food into the digestive tract through the mouth. Food is crushed by the teeth, mixed with saliva, and begins digestion.
Digestion: Processing of food into nutrients that can be utilized by cells. This occurs through two types of actions:
- Mechanical: Physically breaking down food through cutting, grinding, and churning. This occurs in the mouth and stomach.
- Chemical: Transforming food into simpler compounds using substances that cause chemical changes. This starts
Animal Respiration and Digestion
Digestive System Evolution
Primitive organisms with extracellular digestion, like microphages, had a simple digestive system. Food particles entered a single opening, serving as both mouth and anus, where digestion and absorption occurred. Nematodes evolved two openings: a mouth for ingestion and an anus for egestion. Macrophages developed specialized structures like jaws or teeth for food intake and muscles for peristaltic movement along the digestive tract. Further developments increased digestive
Read MoreAnimal Physiology: Nutrition, Digestion, Respiration, Circulation, and Excretion
Animal Physiology: Key Systems
Nutrition
The process by which living organisms obtain energy and matter for growth, development, and vital functions. Animals use energy from organic matter catabolism.
- Ingestion and digestion of food to release nutrients.
- Distribution of nutrients to body cells.
- Absorption of oxygen and transport to cells.
- Cell metabolism
- Waste removal from cells.
- Waste excretion.
Digestion
Macromolecule transformation into smaller, absorbable molecules.
- Physical/Mechanical: Fragmenting food,
Human Body Functions: Metabolism, Respiration, and Excretion
Metabolism
- Formation of complex substances from simpler ones, e.g., protein synthesis from amino acids.
- Glucose and other organic compounds.
- Burning nutrients to release energy.
- Note: The term “consumption” is not accurate for energy, as it transforms (e.g., chemical energy in organic substances to heat).
- In winter, it’s colder.
- Chewing expends energy.
- Calculation example: (7.4 x 42 + 428 x 1.65 + 572 = 1589)
- Consuming a varied diet is important.
- Diseases: Beriberi, malaria, and rickets.
- Global distribution