Human Body Structure and Organization
Levels of Human Body Organization
The human body is composed of many elements, atoms, molecules, cells, tissues, organs, and systems.
- Elements: Basic substances that make up matter.
- Atoms: The smallest units of elements that form living organisms.
- Molecules: Components from which cells build their structures.
- Cells: The basic unit of living beings.
- Tissue: A group of specialized cells associated to perform a specific function.
- Organs: Formed by different tissues working together for a specific function.
Hormonal Imbalances: Causes, Effects, and Key Endocrine Concepts
Endocrine Disorders and Hormonal Imbalances
Cushing’s Disease
Cushing’s disease is characterized by the excessive breakdown of tissue proteins and lipid reserves, and impaired glucose metabolism.
- Primary Cause: Overproduction of glucocorticosteroids.
Diabetes Insipidus: Key Symptoms
Polyuria
Polyuria is excessive urination associated with diabetes insipidus.
- Cause: Underproduction of ADH (Anti-Diuretic Hormone).
Polydipsia
Polydipsia is excessive thirst associated with diabetes insipidus.
- Cause: Associated
Biological Evolution: Core Theories and Evidentiary Support
Unit 5: Understanding Evolution
Evolution explains the origin of diverse life forms as a result of changes in their genetic makeup. It posits that all species descended from other, distinct, pre-existing species. Natural processes, including mechanisms like natural selection, have shaped life on Earth over vast periods, long before Darwin’s pivotal contributions.
1. Fixist Theories
These theories propose that living beings were created by God and have experienced no changes or modifications (remaining
Read MoreKey Concepts in Cardiovascular and Respiratory Physiology
Fluid Dynamics and Capillary Exchange
Factors Affecting Capillary Fluid Shift
- Hemorrhage: Leads to a decrease in capillary hydrostatic pressure, causing a fluid shift towards absorption from the interstitium.
- Exercise: Increases capillary hydrostatic pressure, promoting a fluid shift towards filtration into the interstitium.
- Malnutrition: Results in decreased plasma protein concentration (and thus decreased plasma oncotic pressure), leading to a fluid shift towards filtration.
Pressure Gradients in Capillary
Read MoreHuman Body Systems and Functions
The Senses
The Sense of Sight
Components of the eye:
- Extraocular muscles
- Sclera
- Choroid
- Optic nerve
- Crystalline lens
- Iris
- Cornea
- Aqueous humor
- Vitreous humor
- Retina
The Sense of Hearing
Components of the ear:
- Pinna
- External auditory canal
- Eardrum
- Semicircular canals
- Cochlea
- Auditory nerve
- Eustachian tube
- Ossicles (chain of bones)
Coordination Systems
Nervous System
This system receives and transmits information rapidly by electrical impulses, through sensory neurons.
Endocrine System
This system consists of glands that secrete
Read MoreUnderstanding Cholesterol and Protein for Better Health
Cholesterol
Cholesterol can be synthesized by the body, absorbed by the intestine, and causes excess cardiovascular problems.
HDL cholesterol collects in the arteries and transports it to the liver. Exercise and moderate alcohol consumption increase HDL, while smoking decreases it.
Functions of Cholesterol
- Synthesis of steroid hormones
- Synthesis of bile acids necessary for the absorption of fats
- Synthesis of vitamin D
- Formation of cell membranes
Protein
A protein is considered more complete the more amino