Human Biology: Blood, Excretion, Nutrition, and More
Human Biology: An Overview
Blood Composition and Function
Blood is composed of plasma and three types of cells:
- Erythrocytes: Red blood cells without a nucleus, responsible for oxygen transport.
- Leukocytes: White blood cells that defend the body against infections.
- Platelets: Involved in blood coagulation.
Diastole refers to the relaxation of the heart chambers, while systole refers to their contraction.
Excretion and the Kidneys
Excretion is the process of eliminating waste substances from the blood.
The
Read MoreDarwinian Evolution: Natural Selection, Speciation, and Mechanisms
Lesson 1: Darwin and Natural Selection
Evidence for Evolution:
- Selection is a plausible mechanism for species change.
- The fossil record shows species change over time (e.g., whale hind legs).
- Homology of forelimb structure and comparative embryology suggest common ancestry.
- Biogeography showed patterns of distribution of organisms consistent with ancestor-descendant relationships (e.g., beak sizes).
Evolution of drug resistance and viruses is important to our health and society.
The State of Knowledge
Read MoreMolecular Biology: DNA Transcription, Translation, and Genetics
DNA Transcription and RNA Synthesis
During transcription, an RNA molecule, called messenger RNA (mRNA), is synthesized. This mRNA is complementary to the DNA fragment that carries the information for a specific protein. This molecule provides the information necessary for ribosomal protein synthesis. Cells produce proteins, such as enzymes and structural proteins, that may not always be needed. This can lead to a progressive deterioration of cellular functions and activities.
Peptide Mutations
a) AAT
Read MoreJoint and Muscle Proprioceptors: Types and Movements
Anatomical Classification of Joints
Based on the tissue that is located between joint surfaces. Types:
- Syndesmosis: A union made of fibrous connective tissue or dense fibrous elastic tissue. Examples of dense fibrous tissue are the interosseous membranes that unite the diaphyses of the two bones of the forearm and leg. An example of binding elastic tissue are the yellow ligaments that join the vertebral arches to each other.
- Synchondrosis: Here the tissue is hyaline cartilage. As an example, we have
Cellular Structures and Genetic Processes: An In-Depth Look
Nucleus
The nucleus contains genetic information. It can be single or multiple, round, cubic, or poly-lobed. It’s located either centrally or laterally within the cell. We distinguish between the interphase nucleus and the nucleus undergoing mitosis.
Parts:
- Nuclear membrane: Double membrane (external and internal).
- Nuclear pores: Formed by the nuclear pore complex, an octagon of 8 subunits of nuclear pore proteins with a central granule. It allows the exchange of molecules in both directions.
- Matrix:
Human Nutrition: Essential Nutrients and Balanced Diet
Food and Nutrition
Nutrition describes the set of processes by which an organism obtains energy and matter necessary to develop its own structures and perform vital functions. Nutrition is an involuntary process that involves various organs and systems. Food makes up our diet and is necessary for our nutrition. Food is a conscious and voluntary act.
Types of Nutrients
- Inorganic nutrients: These can come from animal and plant sources, and also from non-organic sources. Examples include water and mineral