Blood, Circulatory and Respiratory Systems Overview

These flashcards cover key concepts, facts, and definitions related to blood, circulatory, respiratory, and digestive systems as discussed in the lecture.

What are the major functions of blood?

Transport of nutrients, immune protection, and regulation of pH and temperature.

What role does albumin play in blood?

It contributes most directly to blood viscosity and osmolarity.

What is the soluble precursor to fibrin?

Fibrinogen.

How many oxygen molecules can each hemoglobin molecule carry?

Up to 4 oxygen molecules.

Why is blood type O considered the universal donor?

It has no antigens.

Which white blood cell releases histamine and heparin?

Basophil.

What does a high neutrophil count typically indicate?

Bacterial infection.

From what do platelets originate?

Fragments of megakaryocytes.

What differentiates agglutination from coagulation?

Agglutination is antibody-mediated.

What does the pulmonary circuit do?

Sends blood to the lungs and back.

What vessel does the right ventricle send blood into?

Pulmonary trunk.

What occurs during the 'lub' heart sound (S1)?

AV valves close.

How is stroke volume defined?

Blood pumped per beat.

What layers compose capillaries?

Tunica interna only.

What is primarily found in the tunica media?

Smooth muscle and elastic tissue.

Which blood vessel has the greatest capacity for blood storage?

Veins.

What is a function of the lymphatic system?

Absorption of lipids.

Which immune cell becomes a macrophage upon leaving the bloodstream?

Monocyte.

Which structure prevents backflow of blood into the atria?

AV valves.

What happens during ventricular systole?

Semilunar valves open.

What is the primary function of the respiratory system?

Gas exchange.

What does the mucociliary escalator do?

Moves mucus up toward the throat.

Why does the left lung have fewer lobes?

It accommodates the heart.

What does surfactant prevent?

Collapse of alveoli.

When does air flow into the lungs?

When intrapulmonary pressure decreases.

What muscles are used in quiet breathing?

Diaphragm and external intercostals.

What function does the VRG in the medulla serve?

It acts as the pacemaker of breathing.

What is the most potent stimulus for respiration?

pH.

What happens during hyperventilation?

CO₂ levels decrease.

What is the digestive system's main job?

Break down and absorb nutrients.

How does chemical digestion break down molecules?

By enzymatic hydrolysis.

What is the primary function of the stomach?

Stores food and begins protein digestion.

What do parietal cells secrete?

Intrinsic factor and HCl.

What do chief cells produce?

Pepsinogen.

Where does most chemical digestion and nutrient absorption occur?

In the small intestine.

What does the enteric nervous system control?

Motility and secretion in the gut.

What is the gut-brain axis?

Micobiome and ENS communication.

Which enzyme digests fats after activation in the stomach?

Lingual lipase.

What is the primary role of the large intestine?

Water absorption and compaction.

What does a buffer resist changes in?

pH.

What may cause respiratory acidosis?

Hypoventilation.

What does the urinary system regulate?

Blood volume, osmolarity, and pH.

What is the functional unit of the kidney?

Nephron.

Why is the afferent arteriole larger than the efferent arteriole?

To create high glomerular pressure.

What does the filtration membrane prevent from passing?

Large proteins and blood cells.

What does the PCT reabsorb?

~65% of filtrate including electrolytes, water, glucose.

What does the nephron loop create?

Osmotic gradient for water reabsorption.

What does aldosterone cause the DCT to do?

Reabsorb Na⁺ and water while secreting K⁺.

What is the function of natriuretic peptides?

Increase sodium and water excretion.

What does the collecting duct become increasingly concentrated due to?

Surrounding tissues having high osmolarity.

What drives glomerular filtration?

High blood pressure in glomerular capillaries.

What does tubular secretion remove?

Wastes, drugs, and excess ions.

Where does spermatogenesis occur?

In the seminiferous tubules.

What does the corpus luteum secrete?

Progesterone.

Where does fertilization usually occur?

In the uterine tube.

Which hormone maintains the uterine lining in early pregnancy?

HCG.

What is the primary function of amniotic fluid?

Cushion and protect the fetus.

What does a karyotype display?

Chromosome pairs.

Where are sex-linked traits typically carried?

On the X chromosome.