Digestive, Excretory, and Plant Physiology Vocabulary

Vocabulary flashcards covering major terms in digestion, excretion, and plant physiology from the lecture notes.

Digestive system

Body system responsible for breaking down food, absorbing nutrients, and eliminating undigested waste.

Mechanical digestion

Physical breakdown of food by chewing or churning.

Chemical digestion

Breakdown of food using enzymes and acids.

Enzyme

Protein catalyst that speeds up chemical reactions in the body.

Amylase

Digestive enzyme that begins starch digestion.

Ingestion

Taking food into the mouth.

Digestion (process step)

Conversion of food into simpler, absorbable substances.

Absorption

Uptake of digested nutrients into the bloodstream.

Assimilation

Utilization of absorbed nutrients by body cells.

Egestion

Removal of undigested material from the body.

Bolus

Moist ball of chewed food formed in the mouth.

Mastication

Chewing; first stage of mechanical digestion.

Saliva

Fluid containing salivary amylase that moistens food.

Esophagus

Muscular tube connecting mouth to stomach.

Peristalsis

Wave-like muscular contractions that move food through the digestive tract.

Stomach

J-shaped organ where food is mixed with gastric juices.

Chyme

Semi-fluid mixture of partially digested food and gastric juice.

Liver

Organ that produces bile and detoxifies blood.

Bile

Green fluid that emulsifies fats.

Gall bladder

Small organ that stores bile.

Small intestine

Long tube where most digestion and nutrient absorption occur.

Duodenum

First section of the small intestine where most chemical digestion begins.

Jejunum

Middle section (≈2.5 m) of the small intestine for absorption.

Ileum

Final section of the small intestine leading to the large intestine.

Large intestine

Organ that absorbs water and forms feces; includes caecum, colon, rectum.

Secretion

Production and release of digestive enzymes or acids.

Excretory wastes

Unwanted metabolic by-products such as urea, uric acid, ammonia, CO₂, salts, and water.

Excretory system

Body system that removes metabolic wastes.

Kidneys

Bean-shaped organs that filter blood and form urine.

Lungs (excretory)

Organs that excrete carbon dioxide and water vapor during breathing.

Liver (detox)

Organ that removes toxins and breaks down nitrogenous compounds.

Skin (sweat glands)

Releases excess water and salts through perspiration.

Urea

Main nitrogenous waste formed from protein breakdown.

Uric acid

Nitrogenous waste produced from DNA/RNA breakdown.

Nephron

Functional filtering unit of the kidney.

Renal artery

Blood vessel delivering oxygenated blood to the kidneys.

Renal vein

Blood vessel carrying filtered blood away from the kidneys.

Glomerulus

Cluster of capillaries in a nephron where filtration occurs.

Bowman’s capsule

Cup-shaped structure that encases the glomerulus.

Filtration (kidney)

First step in urine formation where plasma is filtered into Bowman’s capsule.

Reabsorption

Return of useful substances from nephron back to blood.

Excretion (kidney process)

Removal of remaining waste and water as urine.

Ureter

Tube carrying urine from kidney to urinary bladder.

Urinary bladder

Organ that stores urine until excretion.

Urethra

Tube that carries urine from bladder to outside the body.

Sphincter (urinary)

Circular muscle controlling urine release at the urethral opening.

Photosynthesis

Process by which plants convert light energy, CO₂, and water into glucose and oxygen.

Xylem

Vascular tissue transporting water and minerals upward; turns red in dyed water experiments.

Phloem

Vascular tissue that distributes sugars from leaves to other plant parts.

Plant transport

Movement of water, minerals, and sugars throughout a plant via xylem and phloem.

Root hair

Extension of a root cell that increases surface area for absorption.

Root

Underground organ anchoring plant and absorbing water/nutrients.

Stem

Structural axis supporting leaves and transporting substances.

Leaf

Plant organ where photosynthesis occurs; produces food.

Vascular bundle

Ring-arranged group of xylem and phloem in stems.

Cambium

Layer of actively dividing cells between xylem and phloem that contributes to secondary growth.