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Factors that affect conduction rates (myelination, axon diameter & temperature)

By: HWC, Views: 7873

• Several factors determine the rate of conduction of action potentials: • Myelination • Axon diameter • Temperature • The step-by-step depolarization of an axon is called continuous conduction and occurs along unmyelinated axons. • Neurons in the PNS have many axons that ...

Structures that affect circulation - venous return

By: HWC, Views: 7592

• Venous return directly affects cardiac output. • Increased venous return leads directly to greater cardiac output whereas decreased return contributes to decreased output. • Venous return depends on: • Blood volume regulation by the kidneys. • Venous tone. • Skeletal muscl...

Kidney Stones

By: Administrator, Views: 10532

Kidney stones (renal lithiasis, nephrolithiasis) are hard deposits made of minerals and salts that form inside your kidneys. Kidney stones have many causes and can affect any part of your urinary tract — from your kidneys to your bladder. Often, stones form when the urine becomes concentrate...

Hormonal regulation of pregnancy - week 1

By: HWC, Views: 8044

• During pregnancy, hormones play a significant role in triggering changes in the mother and fetus. • Ormones : • Maintain the lining of the uterus and prevent menstruation. Prepare the mammary glands for lactation. • Increase flexibility of the pubic symphysis. • Affect the mot...

Structures that affect circulation - kidneys, blood volume and venous tone

By: HWC, Views: 7702

• Kidneys regulate blood volume and blood osmolarity via salt and water reabsorption. • Increased reabsorption increases blood volume and venous return (and CO). • Decreased reabsorption increases urine production, which decreases blood volume and venous return (and CO). • Systemi...

Hormonal regulation of blood pressure - RAA system

By: HWC, Views: 8172

■ Long-term regulation of MABP is under hormonal control. • Hormones that affect blood pressure and volume: the renin-angiotensin-aldosterone (RAA) system, antidiuretic hormone (ADM), and atrial natriuretic peptide (ANP). ■ Most important hormonal regulator of MABP. Activated by drop in...

Structures that affect circulation - arterioles and vasomotor responses

By: HWC, Views: 7450

■ Small arteries and arterioles determine SVR. ■ Blood pressure drops significantly as blood passes through arterioles. ■ Decreasing arteriole radius and decreased wall elasticity are the main reasons for increased SVR. ■ Small changes in arteriole radius can cause large changes in ...

Mutations and translation

By: HWC, Views: 4266

A mutation, which may arise during replication and/or recombination, is a permanent change in the nucleotide sequence of DNA. Damaged DNA can be mutated either by substitution, deletion or insertion of base pairs. Mutations, for the most part, are harmless except when they lead to cell death or t...

Male Reproductive System - The gonadotropin releasing hormone

By: HWC, Views: 8481

• Hormonal mechanisms that influence male reproductive function involve endocrine tissues contained in the: • Hypothalamus of the brain. • Anterior pituitary. • Testes. • In the hypothalamus, certain neurosecretory cells secrete gonadotropin- releasing hormone (GnRH). • GnRH ...