Raspatory and Urinary System

What is the functional unit of the kidney?

Nephron

What is the outer region of the kidney?

Renal cortex

What is the inner region of the kidney?

Renal medulla

What is the kidney hilus?

The area where blood vessels, nerves, and the ureter enter or leave

What do the ureters do?

Carry urine from the kidneys to the bladder

What does the urethra do?

Carries urine from the bladder out of the body

What is the main function of the glomerulus?

Filters water and small solutes from the blood

What surrounds the glomerulus?

Bowman's capsule

What does the afferent arteriole do?

Carries blood into the glomerulus

What does the efferent arteriole do?

Carries blood away from the glomerulus

What is the main function of the proximal convoluted tubule?

Reabsorbs most filtered water, nutrients, and other useful substances

What is the function of the Loop of Henle?

Creates a concentration gradient that helps the kidneys conserve water

What does the distal convoluted tubule do?

Adjusts electrolyte levels and the final composition of urine

What does the collecting duct do?

Collects filtrate and helps regulate water reabsorption

Where are the renal pyramids located?

Renal medulla

What does renin help regulate?

Blood pressure

What does erythropoietin (EPO) stimulate?

Red blood cell production

What is osmosis?

Movement of water across a selectively permeable membrane

Which ion is especially important in regulating extracellular fluid balance?

Sodium

What is glomerular filtration?

Movement of water and small solutes from blood into the nephron

What is tubular reabsorption?

Movement of useful substances from the nephron back into the blood

What is tubular secretion?

Movement of selected substances from blood into the nephron tubule

What are the main functions of the urinary system?

Remove wastes and regulate water, electrolytes, and acid-base balance

What usually happens to urine output when the body is dehydrated?

Urine output decreases as the kidneys conserve water

Why does urine output decrease when the body needs to conserve water?

More water is reabsorbed into the blood

How does the circulatory system help the urinary system?

Carries blood and metabolic wastes to the kidneys

What does retroperitoneal mean?

Located behind the peritoneum

What helps protect and hold the kidneys in place?

Renal capsule, surrounding fat, and renal fascia

What is uremia?

Accumulation of urea and other wastes in the blood

What is anuria?

Little or no urine production

What is urinary incontinence?

Involuntary loss of urine

Why are women more susceptible to urinary tract infections?

The urethra is shorter and its opening is closer to the anus

What is the path of urine after the collecting ducts?

Renal pelvis → ureter → bladder → urethra

Why are blood cells normally absent from kidney filtrate?

They are generally too large to pass through the filtration barrier

What is urea?

A nitrogen-containing waste product removed from the blood by the kidneys

What is the main function of the urinary bladder?

Temporarily stores urine

What receives urine before it enters the ureter?

Renal pelvis

What is an electrolyte?

A substance that forms electrically charged ions in solution

Why is electrolyte balance important?

It helps maintain fluid balance and normal cell function

What is the difference between a ureter and a urethra?

Ureters carry urine to the bladder; the urethra carries urine outside the body

What is active transport?

Movement of substances against their concentration gradient using energy

What is the primary function of the respiratory system?

Exchange oxygen and carbon dioxide

What happens to the diaphragm during inhalation?

It contracts, flattens, and moves downward

What happens to thoracic cavity volume during inhalation?

It increases

What happens to lung pressure during inhalation?

It falls below atmospheric pressure, allowing air to enter

What happens during normal exhalation?

Thoracic volume decreases, lung pressure rises, and air moves out

Which intercostal muscles assist inhalation?

External intercostal muscles

What is the windpipe called?

Trachea

Which structure is shared by the respiratory and digestive systems?

Pharynx

What is the glottis?

The opening of the larynx into the airway

What does the epiglottis do?

Helps keep food and liquid out of the airway during swallowing

What can happen if food enters the trachea?

Aspiration, which can cause choking or lung complications

What are the two main branches of the trachea?

Right and left primary bronchi

What is the pathway of air into the lungs?

Trachea → bronchi → bronchioles → alveoli

Where does most gas exchange occur?

Alveoli

What are alveoli?

Tiny air sacs surrounded by pulmonary capillaries

Which direction does oxygen diffuse at the alveoli?

From alveolar air into the blood

Which direction does carbon dioxide diffuse at the alveoli?

From blood into alveolar air to be exhaled

What is external respiration?

Gas exchange between alveoli and pulmonary blood

What is internal respiration?

Gas exchange between blood and body tissues

What is pulmonary ventilation?

Movement of air into and out of the lungs

What is tidal volume?

Amount of air inhaled or exhaled during a normal breath

What is inspiratory reserve volume?

Extra air that can be inhaled after a normal inhalation

What is expiratory reserve volume?

Extra air that can be forcibly exhaled after a normal exhalation

What is residual volume?

Air remaining in the lungs after maximal exhalation

What is dead space air?

Air in conducting passages that does not directly participate in gas exchange

Which is largest in diameter: trachea, bronchiole, alveolar duct, or alveolus?

Trachea

What do nasal conchae help accomplish?

Warm, humidify, and filter inhaled air by creating turbulence

What is the function of respiratory mucus?

Traps dust, particles, and pathogens

What do respiratory cilia do?

Move mucus and trapped particles toward the throat

What does surfactant do?

Reduces alveolar surface tension and helps prevent alveolar collapse

Why is the large surface area of alveoli important?

It allows efficient gas exchange

What do pulmonary arteries carry?

Oxygen-poor blood from the heart to the lungs

What do pulmonary veins carry?

Oxygen-rich blood from the lungs toward the heart

What is a major function of the larynx?

Conducts air and houses the vocal cords

What keeps the trachea from collapsing?

C-shaped rings of cartilage

Why are the tracheal cartilage rings important?

They help keep the airway open

What are bronchioles?

Small branching airways within the lungs

What are lung lobules?

Small subdivisions of lung tissue supplied by smaller airways

What happens to blood carbon dioxide during breath-holding?

It generally increases

What happens to blood pH as carbon dioxide increases?

It generally decreases, making the blood more acidic

How can increased carbon dioxide lower blood pH?

Carbon dioxide forms carbonic acid, which releases hydrogen ions

What usually happens to blood carbon dioxide during hyperventilation?

It decreases

How does hyperventilation usually affect blood pH?

It raises pH, potentially causing respiratory alkalosis

What is emphysema?

Damage to alveolar walls that reduces gas-exchange surface area

What can contribute to emphysema and lung damage?

Smoking, secondhand smoke, and inhaled irritants

What is chronic bronchitis?

Chronic airway inflammation often associated with excess mucus production

What happens during an asthma attack?

Airways become inflamed and narrowed, making breathing difficult

What type of cells commonly give rise to lung cancers?

Epithelial cells lining respiratory passages or other lung tissues

How does smoking harm the respiratory system?

Damages airway tissues and cilia and increases chronic lung disease and cancer risk

What separates the thoracic and abdominal cavities?

Diaphragm

What happens to the diaphragm during quiet exhalation?

It relaxes and moves upward

What moves oxygen from alveoli into pulmonary blood?

Diffusion down a partial-pressure gradient

What is the difference between ventilation and respiration?

Ventilation moves air; respiration refers to gas exchange

What happens to air pressure when thoracic volume increases?

Pressure decreases

What happens to air pressure when thoracic volume decreases?

Pressure increases

What is the main purpose of pulmonary circulation?

Moves blood between the heart and lungs for gas exchange

Why does oxygen move from alveoli into the blood?

Alveolar oxygen partial pressure is higher than in incoming pulmonary blood

Why does carbon dioxide move from blood into alveoli?

Blood carbon dioxide partial pressure is higher than in alveolar air

How does the respiratory system help regulate blood pH?

By adjusting how much carbon dioxide is exhaled