Human Anatomy & Physiology II - Topic 9&10

Glomerulus

Tuft of capillaries surrounded by Bowman’s capsule; filters the blood based on size

Urinalysis

Analysis of urine to diagnose disease

Urochrome

Heme-derived pigment that imparts the typical yellow color of urine

Oliguria

Below normal urine production of 400-500 mL/ day

Anuria

Absence of urine produced; production of 50 mL or less per day

Polyuria/ diuresis

Urine production in excess of 2.5 L/day; may be caused by diabetes insipidus, diabetes mellitus, or excessive use of diuretics

Specific gravity

Weight of a liquid compared to pure water, which has a specific gravity of 1.0

Leukocyte esterase

Enzyme produced by leukocytes that can be detected in the urine and that serves as an indirect indicator of urinary tract infection

Urine osmolarity

It is the measurement of the concentration of particles in urine, reflecting the balance of water and electrolytes in the body

Osteomalacia

It is a condition characterized by softening of the bones due to impaired bone metabolism, primarily resulting from deficiencies in phosphate, calcium, and vitamin D

Renal fat pad

Adipose tissue between the renal fascia and the renal capsule that provides protective cushioning to the kidney

Renal cortex

Outer part of the kidney contains all of the nephrons

Nephrons

Functional units of the kidney that carry out all filtration and modification to produce urine

Medulla

Inner region of kidney containing the renal pyramids

Renal columns

Extensions of the renal cortex into the renal medulla; separates the renal pyramids; contains blood vessels and connective tissues

Renal papillae

Medullary area of the renal pyramids where collecting ducts empty urine into the minor calyces

Calyces

Cup-like structures receiving urine from the collecting ducts where it passes on to the renal pelvis and ureter

Renal hilum

Recessed medial area of the kidney through which the renal artery, renal vein, ureters, lymphatics, and nerves pass

Proximal convoluted tubules (PCTs)

Tortuous tubules receive filtrate from Bowman’s capsule; the most active part of the nephron is reabsorption and secretion

Distal convoluted tubules

Portions of the nephron distal to the loop of Henle that receive hypnotic filtrate from the loop of Henle and empty into collecting ducts

Loop of Henle

Descending and ascending portions between the proximal and distal convoluted tubules

Cortical nephrons

Nephrons with loops of Henle that do not extend into the renal medulla

Juxtamedullary nephrons

Nephrons are adjacent to the border of the cortex and medulla with loops of Henle that extend into the renal medulla

Interlobar Arteries

They are vessels of renal circulation that supply the renal lobes

Peritubular capillaries

Tiny blood vessels in the kidneys, supplied by the efferent arteriole, that travel alongside nephrons

Renal corpuscle

Consists of the glomerulus and Bowman’s capsule

Podocytes

Cells forming finger-like processes; form the visceral layer of Bowman’s capsule

Pedicels

Finger-like projections of podocytes surrounding glomerular capillaries

Fenestrations

Small windows through a cell, allowing rapid filtration based on size; formed in such a way as to allow substances to cross through a cell without mixing with cell contents

Juxtaglomerular apparatus (JGA)

Located at the juncture of the DCT and the afferent and efferent arterioles of the glomerulus; plays a role in the regulation of renal blood flow and GFR

Macula Densa

Cells found in the part of the DCT forming the JGA; sense Na + concentration in the forming urine

Juxtaglomerular cell

Modified smooth muscle cells of the afferent arteriole; secretes renin in response to a drop in blood pressure

Angiotensin I

Protein produced through the enzymatic action of renin on angiotensinogen; inactive precursor of angiotensin II

Angiotensin II

Protein produced by the enzymatic action of ACE on inactive angiotensin I; actively causes vasoconstriction and stimulates aldosterone release by the adrenal cortex

Angiotensinogen

Inactive protein in the circulation produced by the liver; precursor of angiotensin I ; must be modified by the enzymes renin and ACE to be activated

Brush border

Fuzzy appearance of the small intestinal mucosa created by microvilli

Aquaporin

Protein-forming water channels through the lipid bilayer of the cell; allows water to cross

Paracrine signal

It is a form of cell communication where a cell produces a signal in the form of chemicals to induce changes in nearby cells

Hydrophobic

Property of a substance that tends to repel or fail to mix with water

Urethra

Transports urine from the bladder to the outside environment

Trigone

Area at the base of the bladder marked by the two ureters in the posterior-lateral aspect and the urethral orifice in the anterior aspect oriented like points on a triangle

Internal urinary sphincter

Smooth muscle at the juncture of the bladder and urethra; relaxes as the bladder fills to allow urine into urethra

External urinary sphincter

Skeletal muscle; must be relaxed consciously to void urine

Destructor muscle

Smooth muscle in the bladder wall; fibers run in all directions to reduce the size of the organ when emptying it of urine

Micturition

Process of urination

Sacral micturition center

Groups of neurons in the sacral region of the spinal cord that controls urination

Pubic symphysis

It is the secondary cartilaginous joint located between the left and right pubic bones near the midline of the body

Paraplegia

Paralysis of the legs and lower body, typically caused by spinal injury or disease

Glomerular filtration rate (GFR)

The volume of fluid that filters through the glomerular capillaries into the Bowman’s capsule per unit of time, kidney function in the filtration of blood plasma

Hydrostatic pressure

Pressure exerted by a fluid against a wall, caused by its own weight or pumping force

Interstitial tissues

They are the connective and supporting tissues that are situated outside the blood and lymphatic vessels and the parenchyma of organs

Afferent capillaries

They are the blood vessels that bring blood into the glomerulus, a network of small blood vessels in the kidney for filtration

Autoregulation

This is an internal adaptive mechanism in many biological systems that adjusts the system’s response to stimuli, maintaining a stable state

Electrochemical gradient

It is the difference in electrical potential and chemical concentration across a membrane for an ion

Homeostasis

Biological systems maintain stability and optimal conditions for survival

Peritubular capillaries

These are tiny blood vessels in the renal system supplied by the efferent arteriole

Isotonic fluids

Solutions that have the same concentration of solutes as cells and blood

Vasa recta

Branches of the efferent arterioles that parallel the course of the loops of Henle, form a portal system

Paracellular route

The transfer of substances across an epithelium by passing through the intercellular space between cells

Hypertonic

A solution that has a higher osmotic pressure or a greater concentration of solute particles than another solution

Principal cell

Found in collecting ducts and possess channels for the recovery or loss of sodium and potassium

Intercalated cell

Specialized cell of the collecting ducts that secrete or absorb acid or bicarbonate; important in acid-base balance

Basolateral membrane

Part of the cell membrane that faces outwards towards the interstitium and away from the lumen, particularly in polarized cells like epithelial cells and neurons

Exocytosis

Process that transports materials from inside the cell to the external part of the cell using energy, making it a type of active transport

Myogenic mechanism

Mechanism by which smooth muscle responds to stretch by contracting

Tubuloglomerular feedback

Feedback mechanism involving the JGA; a paracrine signaling mechanism utilizing ATP, adenosine, and nitric oxide (NO)

Celiac plexus

Network of nerves in the abdomen that distributes nerve fibers to the abdominal organs

Splanchnic nerves

Paired visceral nerves that help innervate internal organs

ACE( Angiotensin converting enzyme)

Not a hormone but it is functionally important in regulating systemic blood pressure and kidney function

Antidiuretic Hormone (ADH)

Known as vasopressin , a hormone that increases the volume of water absorbed from the collecting tubules of the kidney

Prostaglandins

Hormone-like compounds found in nearly all tissues, derived from arachidonic acid

Hydroxylation

A chemical process that introduces a hydroxyl group ( - OH) into an organic compound

Congestive heart failure

Chronic progressive condition that occurs when the heart is unable to pump blood efficiently, leading to a buildup of fluid within the heart and inefficient pumping

Renin

Enzyme produced by Juxtaglomerular cells in response to decreased blood pressure or sympathetic nervous activity

Diuretic

Compounds that increase urine output, leading to decreased water conservation

Carotid sinus

Neurovascular structure located at the bifurcation of the common carotid artery

Cardiomyocytes

Cardiac muscle cells that build up the muscle walls of both the atria and the ventricles

Anti-hypertensive

Medication used to manage hypertension or high blood pressure

Aneurysm

Bulge or dilation in the wall of an artery, often resulting from a weak area in the artery wall

Buffer

Solution that resists changes in pH when small amounts of an acid or a base are added

Electrical Gradient

Potential that moves ions due to ion imbalance

Hematocrit

Volume percentage of red blood cells in blood, measured as part of a blood test

Pharmacokinetics

Branch of pharmacology that describes how the body affects a specific substance after administration

Glucosuria

Condition characterized by the presence of glucose in the urine, typically due to high blood sugar levels or kidney dysfunction

Renal Threshold

Blood concentration level of a substance at which the kidneys begin to excrete it into the urine

Pleural fluid

Substance that acts as a lubricant for the visceral and parietal layers of the pleura during the movement of breathing

Synovial fluid

It is a viscous, lubricating substance found in the cavities of synovial joints that helps reduce friction between the articulating surfaces of bones

Cerebrospinal fluid (CSF)

It is a clear, colorless fluid that circulates in and around the brain and spinal cord, providing essential cushioning and protection for these vital organs

Meticulous regulation

Involves precise and careful control of biological processes to maintain stability and proper function, such as hormonal balance or enzyme activity in the body

Hydrostatic pressure

Pressure exerted by a fluid against a wall, caused by its own weight or pumping force

Vasodilators

Substances or medications that widen or relax the blood vessels, leading to increased blood flow and reduced blood pressure

Cirrhosis

It is a late stage of scarring (fibrosis) of the liver caused by long-term liver damage and inflammation, leading to a loss of liver function

Subclavian Veins

Large blood vessels located beneath the collarbones that play a crucial role in draining blood from the arms and upper body to the heart

Plasma osmolality

Ratio of solutes to a volume of solvent in the plasma; reflects a person’s state of hydration

Hyponatremia

Lower-than-normal levels of sodium in the blood

Hypernatremia

Abnormal increase in blood sodium levels

Hypokalemia

Abnormally decreased blood levels of potassium

Hyperkalemia

Higher-than-normal blood potassium levels

Hypochloremia

Lower-than-normal blood chloride levels

Hyperchloremia

Higher-than-normal blood chloride levels