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What is ingestion?

Taking food and water into the mouth

What is secretion in digestion?

Release of mucus, enzymes, acid, and hormones

What is propulsion?

Moving food through the GI tract, including by peristalsis

What is mechanical digestion?

Physical breakdown and mixing of food

What is chemical digestion?

Enzymes breaking chemical bonds in food molecules

What is absorption?

Movement of nutrients, water, and ions into blood or lymph

What is defecation?

Elimination of indigestible material as feces

What is the alimentary canal?

The continuous digestive passage from mouth to anus

What is the difference between parietal and visceral peritoneum?

Parietal lines the body wall

visceral covers abdominal organs

What is the function of mesenteries?

Support organs and carry vessels, lymphatics, and nerves

What is the greater omentum?

An apron

What are the four GI wall layers, inside to outside?

Mucosa, submucosa, muscularis externa, serosa or adventitia

What three parts make up the mucosa?

Epithelium, lamina propria, and muscularis mucosae

What does the lamina propria contain?

Connective tissue, vessels, glands, and immune tissue

What is the main role of the submucosa?

Supports vessels, glands, and the submucosal nerve plexus

What does the submucosal plexus regulate?

Local secretions and blood flow

What does the myenteric plexus regulate?

GI motility and muscular contractions

How are GI muscularis externa layers arranged?

Usually inner circular and outer longitudinal muscle

How do serosa and adventitia differ?

Serosa is a lubricating outer membrane

adventitia anchors tissues

How do sympathetic and parasympathetic activity affect digestion?

Sympathetic generally inhibits

parasympathetic stimulates

How do short and long digestive reflexes differ?

Short reflexes use local ENS circuits

long reflexes involve the CNS

What is a bolus?

A moist, chewed mass of food ready for swallowing

What is the oral vestibule?

Space between lips or cheeks and teeth or gums

What is the oral cavity proper?

Space inside the dental arches, behind the teeth

What is the lingual frenulum?

Fold attaching the tongue to the floor of the mouth

How do intrinsic and extrinsic tongue muscles differ?

Intrinsic change tongue shape

extrinsic change its position

Which tongue papillae do not contain taste buds?

Filiform papillae

they provide a rough gripping surface

What causes dental caries?

Bacterial acids from sugar metabolism damage tooth enamel

Where are the parotid glands and what do they secrete?

Near the masseter, produces saliva

watery serous saliva

Where are the submandibular glands?

Beneath the mandible

produce mostly serous saliva

Where are the sublingual glands?

Under the tongue

produce mostly mucous saliva

How do serous and mucous salivary cells differ?

Serous secrete watery enzyme

mucous secrete lubricant

What does salivary amylase do?

Begins carbohydrate digestion

What do lysozyme and secretory IgA do in saliva?

Help protect the oral cavity against pathogens

What stimulates salivation?

Parasympathetic reflexes involving taste or smell and acetylcholine

Which pharynx regions carry swallowed food?

Oropharynx and laryngopharynx

What occurs during the voluntary swallowing phase?

The tongue pushes the bolus toward the oropharynx

What occurs during the pharyngeal phase?

Reflexes protect the airway and propel the bolus downward

What occurs during the esophageal phase?

Peristalsis moves the bolus toward the stomach

What is the muscle arrangement along the esophagus?

Upper skeletal, middle mixed, lower smooth muscle

What are the four major stomach regions?

Cardia, fundus, body, and pyloric region

What does the cardia do?

Receives food entering from the esophagus

What does the fundus do?

Provides storage space, including for swallowed gas

What does the stomach body do?

Stores and churns food with gastric secretions

What does the pylorus do?

Controls chyme passage into the duodenum

Why does the stomach have an extra oblique muscle layer?

To churn food effectively into chyme

What do surface mucous cells in gastric pits do?

Secrete protective mucus against gastric acid and enzymes

What do parietal cells secrete?

Hydrochloric acid and intrinsic factor

Why are HCl and intrinsic factor important?

HCl activates pepsinogen

intrinsic factor enables vitamin B12 absorption

What do chief cells and G cells secrete?

Chief cells secrete pepsinogen

G cells secrete gastrin

What is the difference between catabolism and anabolism?

Catabolism breaks molecules down and anabolism builds molecules

Where does glycolysis occur?

In the cytosol

What does glycolysis produce from one glucose molecule?

Two pyruvate molecules and a net gain of two ATP

Where does the citric acid cycle occur?

In the mitochondrial matrix

What is the main purpose of the citric acid cycle?

To produce electron carriers such as NADH and FADH2

Where does oxidative phosphorylation occur?

At the inner mitochondrial membrane

What does the electron transport chain create?

A hydrogen ion gradient across the inner mitochondrial membrane

How does ATP synthase produce ATP?

Hydrogen ions flow through it and provide energy for ATP synthesis

Why is oxygen necessary for the electron transport chain?

It acts as the final electron acceptor

What is lipolysis?

Breaking triglycerides into glycerol and fatty acids

What is beta oxidation?

Breaking fatty acids into acetyl CoA while producing electron carriers

What is ketogenesis?

Production of ketone bodies from acetyl CoA in the liver

Why can ketone bodies be useful?

They provide an alternative fuel for certain tissues

What is glycogenesis?

Conversion of glucose into stored glycogen

What is glycogenolysis?

Breakdown of glycogen to release stored glucose

What is gluconeogenesis?

Production of new glucose from noncarbohydrate substances

Where does gluconeogenesis mainly occur?

In the liver and certain kidney cells

What is lipogenesis?

Synthesis of fatty acids for energy storage

Where are the kidneys located?

Behind the peritoneum against the posterior abdominal wall

Why is the right kidney lower than the left?

The liver occupies space above it

What are the three protective kidney layers?

Renal fascia, adipose capsule, and renal capsule

What is the renal cortex?

The outer kidney region containing renal corpuscles and tubules

What is the renal medulla?

The inner region containing renal pyramids

What are renal columns?

Cortical tissue between the renal pyramids

What is a renal papilla?

The tip of a pyramid that drains urine into a minor calyx

What is the urine pathway after the renal papilla?

Minor calyx, major calyx, renal pelvis, ureter, bladder, urethra

What is the renal hilum?

The medial opening for blood vessels, nerves, and ureter

What is the functional unit of the kidney?

The nephron

What forms the renal corpuscle?

The glomerulus and glomerular capsule

Where does glomerular filtration occur?

In the renal corpuscle within the cortex

Which arteriole enters and which exits the glomerulus?

The afferent arteriole enters and the efferent arteriole exits

What normally remains in blood during filtration?

Blood cells and most plasma proteins

What does protein in urine suggest?

Possible damage to the glomerular filtration barrier

What is tubular reabsorption?

Movement of substances from filtrate back into blood

What is tubular secretion?

Movement of substances from blood into tubular filtrate

What is the main function of the PCT?

Bulk reabsorption of water, electrolytes, glucose, and amino acids

Why does the PCT have microvilli?

They increase surface area for reabsorption

What happens in the descending nephron loop?

Water leaves and filtrate becomes more concentrated