PCB3713C - Final

Circulatory System Function

Transport system of nutrients, wastes, and others

Driving Pressure

Pressure difference of two points in a vessel causing flow of blood

Transmural Pressure

Pressure difference between the inside and outside of the vessel

Cardiac Output

Volume of blood pumped by the heart per unit of time. 5L/min

Hagen-Poiseuille Equation

Equation that equates flow to the change of volume, fluid viscosity, and time

Turbulent Flow

Noisy flow in a tube due to viscosity and driving pressure. Calculated using Reynolds number (Re)

Capillary Exchange

Movement of a solute through the capillary due to concentration and permeability

Fick’s Law

The rate of diffusion is proportional to how steep the concentration gradient is

Transcapillary hydrostatic pressure difference

Difference in hydrostatic pressure driving water out the capillary

Oncotic pressure difference

Difference in oncotic pressure in the capillary that attracts water in the capillary

Net Filtration Pressure (NFP)

Driving force across a capillary by hydrostatic and oncotic pressures

Lymphatics

System that collects fluid filtered by capillaries that are not reabsorbed

Sinoatrial Node (SA Node)

A pacemaker cell at the top of the heart that regulates hearbeat

Atrioventricular Node (AV Node)

Cell that delays and relays the electrical signal form the atria to the ventricles

Na+ Current

Inward current responsible for rapid depolarization of the heart

Ca2+ Current

Inward current responsible for slow depolarization of the heart

K+ Current

Outward current responsible for repolarization of the heart

Abnormal Cardiac Rhythms

Arrythmias of the heart that result in issues with conduction or automaticity

Atria

Blood receiving chambers of the heart

Ventricles

Large blood pumping chambers of the heart

Cardiac Valves

Passively opens to allow blood to flow one way based on pressure difference

Ventricular Filling

AV valves open to allow blood to fill

Isovolumetric Contraction

Heart contracts to increase pressure. Valves are still closed.

Ventricular Ejection

Semilunar valves open to eject blood out the heart

Isovolumetric Relaxation

Valves close to decrease pressure in the heart

Pressure-volume loop

Diagram depicting the pressure and volume in the LV at certain times of the heart

Mean Arterial Pressure (MAP)

Pressure exerted on the arteries that is universal along the entire body

Neural MAP Regulation

Use of neural pathways for short-term control of MAP

Baroreceptors

Stretch-sensitive mechanoreceptors in the blood vessel walls that increase firing rate based on MAP

Chemoreceptors

PO2 and PCO2 receptors that cause a change in heart rate and vasoconstriction

Low-Pressure Baroreceptors

Stretch-sensitive mechanoreceptors that detect changes in blood volume and causes changes in cardiac output

Integrated Cardiovascular Homeostasis

Vasoconstriction and other cardiovascular adjustments due to physical and mental changes

Hemorrhage Compensation

Loss of blood causing the body to vasoconstrict and start quick RBC production to return to normal MAP

Nephron

Function filtration unit of the kidney

Bowman’s Capsule

A nephron structure of a nephron that surrounds the glomerulus and collects fluid filtered from blood

Glomerular Filtration Barrier

Fenestrations in the glomerular membrane that helps solutes permeate the membrane

Glomerular Filtration Rate (GFR)

Volume of fluid filtered into Bowman’s capsule per unit of time

Ultrafiltration

Process of separating solutes by forcing a solution through a semipermeable membrane

Starling Forces

Fluid forces (Hydrostatic forces and oncotic force) that dictate the filtration of fluid

Renal Blood Flow (RBF)

Blood flow through the renal system. Dictated by constriction of arterioles

Peritubular capillaries

Renal tubules that reabsorb fluid and solutes in the interstitial space

Myogenic Constriction

An increase in pressure causes Ca2+ release that leads to the smooth muscle to contract and resist pressure

Renin-Angiotensin-Aldosterone Axis (RAAS)

A hormonal system activated by low blood pressure or low sodium that increases blood volume and blood pressure through vasoconstriction (angiotensin II) and sodium/water retention (aldosterone

Kidney Na+ Reabsorption

Reabsorption of Na through the proximal tubule and loop of Henle

Transcellular Reabsorption

Ion reabsorption through facilitated diffusion across the apical membrane and an pump out the cell. Remember the charges.

Apical Cotransporters

Usage of a downhill electrochemical gradient to uptake another solute uphill in the same direction

Apical Exchangers

Usage of a downhill electrochemical gradient to uptake another solute uphill in the opposite direction

Aquaporin (AQP)

Channel that allows for water to more readily permeate a membrane

Urea Transport

Passive movement of urea through the nephron to aid in water reabsorption

Glucose Reabsorption

Reclaim of filtered glucose in the Proximal Tubule

Potassium Kidney Transport

Highly regulated potassium is filtered and only essential amount of it is reabsorbed

Water diuresis

High water volume causing kidneys to produce a large volume of dilute urine

Antidiuresis

Low water volume causing kidneys to produce small volume of concentrated urine

Kidney Water Transport

Use of salts to passively move water across membranes

Interstitial Osmolality

Increase in osmolality on the inner side of the medulla due to high Na, Cl, and urea concentrations

Urea Recycling

Reabsorption of urea due to the reabsorption of water causing urea concentration to increase

Bicarbonate

Blood pH buffer used to neutralize acids

Urine Acid Secretion

Excess H+ ions are excreted into urine

Bicarbonate Reabsorption

Secretion of H+ into urine consumes bicarbonate, which causes a new bicarbonate to appear in blood

Respiratory Acidosis

Production of bicarbonate to compensate for increased H+ secretion

ECF Volume

Amount of fluid in the extracellular matrix and primarily controlled by adjusting the total-body NaCl content

ECF Osmolality

Amount of salts in liquid in the extracellular matrix, regulated by adjusting the total-body water content

Hormones

Signaling molecules released by an endocrine tissue into the extracellular fluid

Carrier Proteins

Allows for hydrophobic hormones such as steroid and thyroid hormones to move in the blood

Hypothalamic-pituitary axis

Hypothalamus control over the production of pituitary hormones responsible for growth, stress, reproduction, and metabolism

Tropic Hormones

Gland stimulating hormone to produce further hormones

Trophic Hormones

Growth promoting hormones

Anterior Pituitary

Produces and releases tropic hormones responsible for stimulation of other glands

Posterior Pituitary

Releases AVP to control water balance, and oxytocin

Peptide Hormones

Hormones responsible for signal-transduction systems

Amine Hormones

Small, amino acid–derived hormones that typically act rapidly via second messengers (catecholamines) or alter metabolic rate (thyroid hormones)

Steroid Hormones

Fat-soluble hormones that change gene expression for slow, long-term effects (e.g., cortisol, aldosterone, sex hormones)

Thyroid hormones

Lipid-soluble amine hormones that boost metabolism and support growth and development

Somatotrophs

Growth hormone secreting and producing glands

Thyroid Receptors

Nuclear receptors that alter gene transcription by diffused thyroid hormone

Hypothalamic-pituitary-thyroid axis

Synthesis and secretion of thyroid hormones through a cascade of TRH, TSH, and thyroid hormones

Hypothalamic-pituitary-adrenocortical axis

CRH → ACTH → Adrenal Cortex; the body's main stress hormone pathway

Renin–angiotensin–aldosterone (RAA) axis

Renin → angiotensin I → angiotensin II → aldosterone; increases blood pressure and blood volume.

Islets of Langerhans

Endocrine glands of the pancreas

Pancreatic A Cells

Cells that secrete glucagon

Pancreatic B cells

Cells that secrete proinsulin and insulin

Pancreatic D Cells

Cells that secrete somatostatin

Glucagon

Increases blood glucose by stimulating glycogenolysis and gluconeogenesis

Parathyroid Hormone (PTH)

Increases blood calcium via bone resorption, kidney Ca²⁺ retention, and vitamin D activation

Intestine Wall Anatomy

Structured with a mucosal epithelial layer with layers of smooth muscle outside, and then complete with connective tissue

Digestion

Conversion of food into absorbable products

Absorption

Intake of food and nutrients into the body

Enteric Nervous System (ENS)

A specialized division of the autonomic nervous system embedded in the GI tract that can control digestion independently, regulating motility, secretion, and blood flow

Brain-Gut Axis

Bidirectional system of ENS, GI Hormones, and Immune System components that control GI function

Stomach

A muscular organ that stores, mixes, and digests food using acid and enzymes (HCl, pepsin), protected by mucus, and regulates emptying into the small intestine

Parietal Cell Acid Secretion

CO2 from the basolateral membrane catalyze to form bicarbonate and H+. Results in active transport of HCl across the apical membrane

Pepsinogens

Chief-cell enzyme precursor activated by acid into pepsin for protein digestion. Regulated by ACh

Gastric Acid Neutralization

The use of bicarbonate to neutralize stomach acid prior to the duodenum

Pancreas

Secretes juices that neutralize gastric acidity and secretes digestive enzymes (proteases, amylases, lipases, and nucleases)

Villi

Intestinal microprojections that aid in nutrient and electrolyte absorption. Increases surface area for absorption

Crypts

Base of villi that aid in electrolyte and water secretion

Intestinal Apical Na Absorption

Facilitated transport downhill using the electrochemical gradient

Intestinal Basolateral Na Absorption

Active transport into the ECF using Na-K pumps

Bile

Fluid produced by the liver that aids in lipid digestion and allows excretion of liver byproducts

Sex Determining Region Y (SRY Gene)

A gene on the Y chromosome responsible for determining sex