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T cell receptors

By: HWC, Views: 7402

• T cells are responsible for cell-mediated immunity. • Each T cell contains a unique form of T cell receptor (TCR) on its membrane. • These T cell receptors are produced through a process of genetic recombination which is able to produce millions of different variations. • Each T ce...

Acid-base imbalances - respiratory acidosis and alkalosis

By: HWC, Views: 7983

• The individual mechanisms involved in regulating pH work in concert with each other to ensure that blood pH is maintained within the normal range. • The two categories of pH imbalance are: • Respiratory • Metabolic • Both types of imbalances can cause either acidosis or alka...

Frequency of stimulation and force (Recruitment of motor units and force)

By: HWC, Views: 8043

• Muscle tension depends on the frequency of stimulation. • Muscle twitch: First stimulus. • Wave summation: When a second stimulus excites a partially relaxed muscle, producing a stronger contraction. • Unfused tetanus: Successive stimulations at the same frequency, producing a se...

Introduction to Insulin

By: Administrator, Views: 11824

The islets of Langerhans are composed of three major types of cells: Alpha cells secrete glucagon, elevating blood sugar. Beta cells secrete insulin, maintaining normal blood sugar. Delta cells secrete somatostatin, which suppresses release of glucagon and insulin. Hyposecretion or inadequa...

Junction Types - Tight and Adherens Junctions

By: HWC, Views: 8024

Many tissues contain in tercellular junctions between cells. 1. Tight junction 2. Adherens junction 3. Desmosome 4. Hemidesrnosome 5. Gap junction 1. Tight junction • Web-like strips of proteins fuse together adjacent plasma membranes. • Tight junctions prevent the transport...

Component of feedback systems & Communication and regulation of body systems

By: HWC, Views: 7846

• Primary responsibility for communication and regulation in the body is shared by the nervous and endocrine systems. • The two systems work alone or together in specialized physiological processes called feedback systems to maintain homeostasis. • Feedback systems - or loops - are ...

What is an ecosystem?

By: HWC, Views: 7560

An ecosystem is a community of organisms and their environment. The community forms the living component of the ecosystem. These are called the 'biotic' factors, which means all of the living things in the ecosystem. The environment forms the nonliving component of the ecosystem, such as ...

Nerve Impulse Transmission Animation

By: Administrator, Views: 11096

How nerves transmit impulses. Stimulation of a nerve occurs at a receptor. Sensory receptors Specialized to specific types of stimulation such as heat, cold, light, pressure, or pain. React by initiating a chemical change or impulse. All-or-none principle Means that no transmission occ...

Dendrite Animation

By: Administrator, Views: 11207

Dendrites (from Greek δένδρον déndron, "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimula...