MORE APHY 102 flashcards from topics to focus on i got from person on reddit

what are the phases of the cardiac cycle?

Atrial systole → Ventricular systole (isovolumetric contraction → ventricular ejection) → Ventricular diastole (isovolumetric relaxation) → Atrial diastole → Passive filling

Trace blood flow through the heart.

Superior/Inferior Vena Cava

↓

Right Atrium

↓

Tricuspid Valve

↓

Right Ventricle

↓

Pulmonary Semilunar Valve

↓

Pulmonary Trunk

↓

Pulmonary Arteries

↓

Lungs

↓

Pulmonary Veins

↓

Left Atrium

↓

Mitral (Bicuspid) Valve

↓

Left Ventricle

↓

Aortic Semilunar Valve

↓

Aorta

↓

Body

The time period when the heart is contracting is called…? (ventricles contract to eject blood)

systole

The time period when the heart is relaxing is called…? (heart fills with blood)

diastole

What is the correct order of the heart's electrical conduction system?

SA node → AV node → Bundle of His → Right and Left Bundle Branches → Purkinje fibers

Where are the SA and AV nodes located?

SA node — in the right atrial wall near the SVC entrance. AV node — in the interatrial septum near the coronary sinus

What are the AV valves? Name them and their locations.

Tricuspid valve — between right atrium and right ventricle. Bicuspid (mitral) valve — between left atrium and left ventricle. They prevent backflow into the atria during ventricular contraction.

What are the semilunar valves?

Pulmonary valve — between right ventricle and pulmonary trunk. Aortic valve — between left ventricle and aorta. They prevent backflow into the ventricles during relaxation.

List the main parts of the kidney (external to internal).

Renal capsule → renal cortex → renal medulla (renal pyramids) → renal pelvis → ureter

What are the parts of a nephron in order?

Bowman's capsule (glomerular capsule) → proximal convoluted tubule (PCT) → loop of Henle (descending → ascending) → distal convoluted tubule (DCT) → collecting duct

What is glomerular filtration?

Blood pressure forces water, ions, glucose, and small molecules from the glomerulus into Bowman's capsule. Large proteins and blood cells stay in the blood.

What is GFR? Normal range?

Glomerular Filtration Rate — the volume of filtrate formed per minute. Normal: ~90–120 mL/min.

race the flow of blood through the nephron.

Afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries (or vasa recta around loop of Henle) → venules → renal vein

Trace the flow of filtrate through the nephron.

Bowman's capsule → PCT → descending loop of Henle → ascending loop of Henle → DCT → collecting duct → minor calyx → major calyx → renal pelvis → ureter → bladder

Where does sperm production occur? What is it called?

In the seminiferous tubules of the testes. The process is spermatogenesis.

Where does egg production occur? What is it called?

In the ovaries. The process is oogenesis.

What are the stages of meiosis I?

Prophase I (homologous chromosomes pair up and crossing over occurs) → Metaphase I (homologous pairs line up at equator) → Anaphase I (homologous chromosomes separate) → Telophase I (two haploid cells form)

What are the stages of meiosis II?

Prophase II → Metaphase II (chromosomes line up) → Anaphase II (sister chromatids separate) → Telophase II (four genetically unique haploid cells)

Why is crossing over important?

It exchanges genetic material between homologous chromosomes during Prophase I, creating new combinations of alleles → increases genetic diversity in offspring.

Define the early developmental stages in order.

Zygote (fertilized egg) →Cleavage (rapid cell divisions, no growth) →Morula (solid ball of cells, ~16 cells) → Blastocyst (hollow ball with inner cell mass) → Gastrula – formation of three germ layers (ectoderm, mesoderm, endoderm) → Embryo (from implantation through week 8) → Fetus (week 9 onward)

Describe the mechanics of inhalation.

Diaphragm contracts (flattens) + external intercostals contract → thoracic cavity volume increases → intrapulmonary pressure drops below atmospheric pressure → air flows in.

Describe the mechanics of exhalation.

Diaphragm relaxes (moves up) + external intercostals relax → thoracic volume decreases → intrapulmonary pressure rises above atmospheric → air flows out. Forced exhalation uses internal intercostals and abdominals.

What is Boyle's Law?

Pressure and volume of a gas are inversely proportional at constant temperature. This is the physical principle behind ventilation.

What are the key lung volumes?

Tidal volume (TV) — normal breath (~500 mL). Inspiratory reserve volume (IRV) — extra you can inhale. Expiratory reserve volume (ERV) — extra you can exhale. Residual volume (RV) — air left after maximal exhalation. Vital capacity (VC) = TV + IRV + ERV.

What is pulmonary ventilation?

the mechanical movement of air in and out of the lungs (breathing).

What is external respiration?

Gas exchange between the alveoli and the blood (O₂ in, CO₂ out).

What is internal respiration?

Gas exchange between the blood and the body's tissues (O₂ out, CO₂ in).

What is cellular respiration?

The metabolic process inside cells that uses O₂ to produce ATP from glucose, releasing CO₂ as a byproduct.

What is an endocrine gland? Example?

Secretes hormones directly into the bloodstream (ductless). Example: thyroid, pituitary, adrenal glands.

What is an exocrine gland? Example?

Secretes substances through ducts to a surface or cavity. Example: sweat glands, salivary glands, pancreas (digestive enzymes).

What are paracrine secretions signaling?

A cell releases chemical signals that act on nearby neighboring cells (not through the bloodstream). Example: histamine in inflammation.

What are autocrine secretions signaling?

affect only the cells that secrete them

What does ADH (antidiuretic hormone) do?

Increases water reabsorption in the collecting ducts of the kidneys → concentrated urine, decreased urine output. Released when the body is dehydrated.

In short: causes the kidneys to conserve water

What does parathyroid hormone (PTH) do?

Increases blood calcium levels by: stimulating osteoclasts (bone breakdown), increasing calcium reabsorption in kidneys, and activating vitamin D (increases calcium absorption from gut).

In short: Increases calcium and phosphate levels in the blood

What does oxytocin do?

Stimulates uterine contractions during childbirth and milk ejection (let-down reflex) during breastfeeding. Also involved in bonding/social behavior.

In short: affects muscle contraction of uterus and mammary glands

What is the alimentary canal? List its organs in order.

The continuous tube from mouth to anus. Mouth → pharynx → esophagus → stomach → small intestine (duodenum → jejunum → ileum) → large intestine (cecum → colon → rectum) → anus

What is a bolus?

A soft, rounded mass of chewed food mixed with saliva, formed in the mouth and pushed into the pharynx by the tongue during swallowing.

What is gastrin?

A hormone released by G cells in the stomach lining in response to food (especially proteins). It stimulates gastric acid (HCl) secretion and stomach motility.

What does salivary amylase do?

An enzyme in saliva that breaks down starch (polysaccharides) into maltose (disaccharides). Begins carbohydrate digestion in the mouth. It gets inactivated by stomach acid.