Understanding Human Digestion: Anatomy, Physiology, and Processes
Nutrition and the Digestive System
Nutrition plays a vital role in maintaining the activity of the body’s cells. It encompasses a series of processes:
- Obtaining substances from the external environment and transforming them to reach the cells.
- Utilizing nutrients and oxygen by cells to form new structures, repair tissues, and gain energy.
- Removing cellular waste products for elimination.
These processes involve the digestive, excretory, respiratory, and circulatory systems.
The Digestive System: An Overview
The
Read MoreHormones and Glands: Hypothalamus, Thyroid, and More
Hypothalamus and Pituitary Gland
The hypothalamus controls the body’s hormonal activity and acts as a liaison between the nervous and endocrine systems. Neurons in the hypothalamus receive information from other brain areas and hormones in the blood. They respond by secreting hormones that reach the pituitary gland, regulating its hormone production. The pituitary gland, an endocrine gland, controls the activity of many other endocrine glands and is itself controlled by the hypothalamus.
The pituitary
Read MoreUnderstanding Chromosomes, Cell Reproduction, and Mitosis
Chromosome Structure
Chromosome: These are stick-shaped structures representing chromatin condensation during mitosis. Their size varies according to species.
Centromere: This is the primary constriction point, marking the start of the distal arms. Telomeres may have secondary constrictions near them.
Kinetochore: This protein structure appears at the centromeres and acts as a microtubule organizing center, where the spindle fibers attach.
Telomeres: These are protective caps at chromosome ends, preventing
Read MoreRespiratory System: Anatomy, Function, and Gas Exchange
The Respiratory System: From Air to ATP
O2 intake transforms to ATP.
The Pathway of Air
Driving: Nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli.
Nose
Nares (nostrils): Yellow (smell), reddish (warms air).
Coana: Opening of communication between nostrils and rhino…
Respiratory System: Entrance inland O2 resp. to lungs.
Nasal mass begins, pharynx, larynx, trachea, bronchi,
Bronchioles and allows CO2 output through lungs,
Producing alveoli gas exchange. Via High: mouth, pharynx, larynx = syst.
Read MoreMicrobial Diversity and Roles in Ecosystems
F.1.8 Virus Structure and Diversity
A virus is a non-cellular agent consisting of a protein coat (capsid) and genetic material.
- The genetic material may be DNA (adenovirus) or RNA (retrovirus) and may be single-stranded or double-stranded.
- For some viruses, the protein coat may be exposed (naked capsid), while others may be covered in a membranous bilayer (enveloped capsid).
- Retroviruses have a reverse transcriptase component to allow for the production of viral DNA.
F.1.9 Microscopic Eukaryote Diversity
Examples
Read MoreUnveiling Paleontology: Fossils, Evolution, and Hominization
Paleontology: Unveiling the Past
Paleontology studies the remains of living beings that lived in the past. Since antiquity, fossil remains of animals have been discovered. To explain their existence, the diluvian theory was used, according to which such remains were those of animals now extinct as a result of “Noah’s Flood.” This scenario could not explain the progressive ratio found from fossils dating in older times to more recent times. Thus, the diluvian theory was replaced by the theory of catastrophes.
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