Cellular Communication, Reflexes, and Sensory Receptors: A Comprehensive Overview
Cell-to-cell communication works through synapses. Two parts: the axon terminal of the presynaptic cell and the membrane of the postsynaptic cell. Postsynaptic cells may be neurons or non-neuronal cells. Presynaptic axons are next to either the dendrites or the cell body of the postsynaptic neuron.
Electrical synapses pass signals directly from the cytoplasm of one cell to another through gap junctions. They can flow in both directions. They occur mainly in the CNS. They are found in glial cells,
Read MorePathogenic Substances, Infections, and Viruses: A Comprehensive Guide
Pathogenic Substances Produced by Streptococcus Pyogenes
1. What are the pathogenic substances produced by Streptococcus pyogenes?
- Invasive &pygenic infection:
- Streptococcal sore throat
- Streptococcal pyoderma
- Cellulitis
- Subacute endocarditis
- The most common bacterial cause of sore throat
- Intoxication
- Poststreptococcal sequelae.
Mechanism of Cholera Toxin
2. Explain the mechanism of cholera toxin?
- Produce the symptoms of cholera.
- A-B type ADP-ribosylating toxin
Sub unit A: ADP-ribosylating activity.
Sub unit
Read MoreCommon Pediatric Surgical Conditions
Acute Hematogenous Osteomyelitis (AHO)
Pathophysiology
Bacteremia leads to bacteria localizing in the venous sinuses of long bones due to turbulent blood flow. This increases the risk of clotting and subsequent infection within the bone.
Progression of Infection Inside the Bone
- Phlegmon (inflammatory exudate) formation in the bone marrow
- Subperiosteal spread of the phlegmon (within 2-3 days)
- Spread to the nearest joint
- Spread of the phlegmon to soft tissue
- Sequestrum formation (dead bone tissue)
Septic Arthritis
AHO
Read MoreNervous Tissue: Structure, Function, and Types
Nervous Tissue: Structure, Function, and Types
Nervous tissue is a specialized tissue responsible for communication within the body. It originates from the ectoderm and consists of two main cell types: neurons and glial cells.
Functions of Nervous Tissue
- Detection and Transmission of Nerve Impulses: Neurons receive stimuli through receptors and transmit these impulses to the central nervous system (CNS). They also carry responses back to effector organs.
- Support and Protection: Glial cells provide structural
Genetics and Biotechnology: A Comprehensive Guide
Genetics and Biotechnology
Genome
The genome is the set of genes from one species. Genes are arranged on the chromosome that corresponds to it and the height of the chromosome that corresponds also (map of genes).
Gamete
A gamete is a reproductive cell that has the number of chromosomes halved. Humans have 46 chromosomes. Eggs and sperm are gametes with 23 chromosomes each.
Centromere
The centromere is the point on a chromosome where the two chromatids are joined. When a cell divides, the chromosome divides
Read MoreImmune System: Mechanisms of Specific Immune Response
Mechanisms of Specific Immune Response
Types of Leukocytes
- Basophils: Involved in allergic reactions, release heparin in tissues
- Lymphocytes: Responsible for specific immune response
- Monocytes: Phagocytose bacteria, dead cells, and organic matter; become macrophages in tissues
Types of Specific Immunity
- Antibody-Mediated Immunity (Humoral Response): Involves the production of antibodies by B lymphocytes
- Cell-Mediated Immunity (Cellular Response): Involves the activity of T lymphocytes and macrophages