Neurones can be structurally classified as multipolar, bipolar, or unipolar (pseudounipolar). Multipolar neurones have one axon and multiple dendrites and are common in the central nervous system. Bipolar neurones have one axon and one dendrite and are found in sensory View Diagram Structural Classifications of a Neurone
The olfactory epithelium contains three main cell types: basal cells, olfactory receptor neurons, and sustentacular cells. Basal cells act as stem cells and have the ability to regenerate new olfactory receptor neurons throughout life. Olfactory receptor neurons detect odor molecules View Diagram The Cells of the Olfactory Epithelium Basal Olfactory receptor and Sustentacular
The sliding filament model explains how muscle contraction occurs at the microscopic level. Within each sarcomere, thin actin filaments slide past thick myosin filaments. When stimulated, myosin heads bind to actin and pull them inward, shortening the sarcomere. This process View Diagram Sliding Filament Model Muscle Ultrastructure
The connective tissue layers of a neuron include the endoneurium surrounding individual axons, perineurium enclosing fascicles, and epineurium covering the entire nerve. These layers provide protection, structural support, and facilitate signal conduction. Knowledge of neural connective tissues is essential in View Diagram Connective Tissue Layers of a Neurone
Hemoglobin: Hemoglobin is a protein in red blood cells that binds oxygen in the lungs and releases it in tissues, playing a vital role in respiration and giving blood its red color.
Ketogenesis: Ketogenesis occurs in the liver when carbohydrate intake is low, producing ketone bodies from fatty acids to provide an alternative energy source for tissues like the brain and muscles.
Autosomal Dominant Inheritance: In autosomal dominant inheritance, a single copy of a mutated gene on a non-sex chromosome is sufficient to cause a genetic disorder, which can be passed from just one affected parent.
Aquaporins: Aquaporins are specialized membrane proteins that facilitate the rapid transport of water across cell membranes, playing vital roles in kidney function and water balance.
Alpha Beta T Cell Receptor: The ?? T cell receptor recognizes antigens presented on MHC molecules, allowing T cells to detect infected or abnormal cells and initiate an immune response.
Antigen Processing and Presentation: Antigen processing involves breaking down pathogens into fragments, which are then presented on MHC molecules by antigen-presenting cells to activate T lymphocytes.
Shape of Red Blood Cells: Red blood cells are biconcave discs, a shape that increases surface area for gas exchange and allows flexibility to navigate narrow capillaries.
Sickle Cells: Sickle cells are abnormally shaped red blood cells caused by a mutation in hemoglobin, leading to reduced oxygen transport and increased risk of blockage in blood vessels.
Erythroblastosis Fetalis: Erythroblastosis fetalis is a condition where maternal antibodies attack fetal red blood cells, typically due to Rh incompatibility, leading to anemia, jaundice, and potentially fetal death.
Protein Digesting Enzymes: Enzymes like pepsin in the stomach and trypsin, chymotrypsin, and carboxypeptidase in the small intestine break proteins into peptides and amino acids for absorption.
X linked Recessive Inheritance new: X-linked recessive disorders are caused by mutations on the X chromosome and primarily affect males, as they have only one X; females are often carriers unless both X chromosomes are affected.
Male Chromosomes: Males have one X and one Y chromosome, with the Y chromosome carrying genes essential for male sex determination and development, including the SRY gene responsible for testis formation.
Pseudostratified Epithelium: Pseudostratified epithelium appears layered due to nuclei at different heights but is a single layer of cells, commonly found in the respiratory tract with cilia.
X linked Dominant Inheritance new: X-linked dominant inheritance occurs when a single mutated gene on the X chromosome causes a disorder in both males and females, often more severe in males due to the absence of a second X.
Sperm Fertilization: Sperm must undergo capacitation before penetrating the eggs outer layers and fusing with the oocyte membrane, initiating fertilization and forming a zygote.
IgA Immunity: IgA is the main antibody found in mucosal surfaces like the respiratory and digestive tracts, playing a key role in neutralizing pathogens and preventing their entry into the body.
