Lysosomes: Cell Digestion and Recycling Centers
Lysosomes: Cell Digestion and Recycling
Lysosomes are a set of structures whose function is to digest and lyse materials captured by the cell, including waste substances. These structures could be considered the digestive system of the cell. They are cytoplasmic vesicles, offering great polymorphism, surrounded by a unit membrane and a granular matrix that is dense and heterogeneous. Lysosomes act as digestive vacuoles and are present in all eukaryotic cells. The contents of the lysosome have an
Read MorePlant and Animal Hormones: Functions and Mechanisms
Hormones: Functions and Regulation
Hormones are substances that regulate chemical reactions. Hormones are produced in small quantities, synthesized where they are to act, and transported through the blood, saline, or air.
Phytohormones: Plant Growth Regulators
Phytohormones are organic compounds responsible for plant growth and development. They are synthesized in one part of the plant and typically act elsewhere, producing a physiological response at very low concentrations. Major stimuli affecting
Read MoreCirculatory and Lymphatic Systems: Functions & Components
The International Environment and the Circulatory System
The internal human environment consists of:
- International fluid (plasma): It surrounds and bathes the cells.
- Blood and lymph: They collect and distribute substances the cells need and eliminate waste from the cells through the circulatory system.
The circulatory system consists of two systems:
- The Blood Circulatory System: It carries nutrients and oxygen throughout the body and collects metabolic waste for elimination. The circulatory fluid is
Understanding Blood Vessels, Heart Anatomy, and Cardiac Cycle
Blood Vessels: Arteries, Veins, and Capillaries
There are three types of blood vessels:
- Arteries
- Veins
- Capillaries
Arteries
Arteries are blood vessels with thick, elastic walls. They carry blood from the heart to the organs and branch off into smaller arteries.
Veins
Veins are blood vessels with thinner and less elastic walls than arteries. They have valves that prevent blood from flowing backward. They channel blood from the organs to the heart and are formed by the joining of small veins called venules.
Read MorePlant Physiology: Processes and Mechanisms
Root Pressure
Root pressure is maintained by water accumulation in the root tissues. This generates pressure on xylem sap, pushing it upwards. Guttation is evidence of this phenomenon, typically in tropical jungles.
Gas Exchange
Stomata
Stomata are specialized structures of the epidermis formed by two kidney-shaped cells, called guard cells, which define a space between them, the ostiole. After entering the ostiole, CO2 diffuses into the intercellular spaces of the tissue, enters the cells, and reaches
Read MoreUnderstanding Supracondylar Humerus Fractures & Peptic Ulcers
Supracondylar Fractures of the Humerus
A supracondylar fracture involves the lower end of the humerus, usually affecting the thin portion through the olecranon fossa, just above the fossa, or the metaphysis.
- Most common elbow injuries in children.
- Makes up approximately 60% of elbow injuries.
- Becomes uncommon as age increases.
Fracture Complications
- Compartment syndrome
- Vascular injury/compromise
- Loss of reduction/Malunion – cubitus varus
- Loss of motion
- Pin track infection
- Neurovascular injury with pin placement