Search Results

Medullary osmotic gradient: countercurrent multiplier, urea recycling & vasa recta countercurrent exchange

By: HWC, Views: 8452

▪ The primary cause of the medullary osmotic gradient is the active transport of solutes. • In the ascending limb of the loop, active transport of Na+ ions drives passive reabsorption of Cl- ions. • Addition of these ions to the interstitial fluid of the medulla increases its osmolarity...

Forming urine ( influencing factors), Forming dilute urine & Forming concentrated urine

By: HWC, Views: 8231

• The amount of urine produced by the nephron depends on : • Body fluid volume. • Body fluid composition. • Dilute urine is formed when the body is normally hydrated. • The medullary osmotic gradient determines the osmolarity of the filtrate. • Filtrate osmolarity increase...

Neuron structure and function - sensory neurons, association neurons & motor neurons

By: HWC, Views: 7675

• The primary function of the nervous system is to provide rapid communication within the body to maintain homeostasis. • This function underlies behaviors, thinking and control of organ functions. • The basic functions of the nervous system are provided by: • Sensory neurons • ...

System organization - PPM system types (Somatic, Autonomic & Enteric) and Reflex arc types

By: HWC, Views: 7881

• The PNS consists of all nervous tissue outside of the CNS. • It is divided into three functional components: • Somatic nervous system (SNS) • Autonomic nervous system (ANS) • Enteric nervous system (ENS) • The SNS consists of: • Sensory neurons from skeletal muscles ...

Requirements for nervous signals

By: HWC, Views: 7696

• The function of neurons is to allow communication between cells, thereby maintaining homeostasis. • Electrical signals, called membrane potentials, travel along the membranes of the neurons. • Voltage variability and distance traveled determine the type of nervous signal. 1. Graded...

Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 7864

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...

Resting membrane potential - electrical polarity and maintenance requirements

By: HWC, Views: 7487

• A resting membrane potential exists when there is a buildup of: 1. positive ions outside the membrane. 2. negative ions inside the membrane. • Membranes with opposing charges are said to be polarized. • The difference in charge applies only to the small distance across the membran...

Graded potentials - electrical characteristics and types

By: HWC, Views: 8002

• A graded potential occurs when a gated channel is opened or closed, altering ion flow through the membrane. • Changes in ion and charge distributions cause voltage changes to the resting membrane potential. • The strength of the stimulus determines the number of gated channels affect...

Action potentials - electrical characteristics and generation

By: HWC, Views: 7589

• An action potential is the nervous impulse or signal for long distance communication. Each action potential is generated at the cell's trigger zone. • Action potentials are considered an all-or-nothing phenomena because they are either generated or not. • The generation of an action...