Human Digestive System Overview

<p>As glucose (C)</p> Signup and view all the answers

<p>Oxygenated blood (A)</p> Signup and view all the answers

<p>Facilitate gas exchange between blood and tissues (A)</p> Signup and view all the answers

<p>Right atrium (A)</p> Signup and view all the answers

<p>Breaks down proteins (A)</p> Signup and view all the answers

<p>Tongue's movement to the back of the mouth (D)</p> Signup and view all the answers

<p>To activate pepsin and keep it functioning (C)</p> Signup and view all the answers

<p>Molars (D)</p> Signup and view all the answers

<p>Peristalsis (B)</p> Signup and view all the answers

<p>It is the primary site for nutrient absorption (A)</p> Signup and view all the answers

<p>Parietal cells (B)</p> Signup and view all the answers

<p>Salivary amylase (B)</p> Signup and view all the answers

<p>Diffusion across the plasma membrane (A)</p> Signup and view all the answers

<p>Contraction of external intercostal muscles and diaphragm (B)</p> Signup and view all the answers

<p>Stimulates a decrease in blood pH (B)</p> Signup and view all the answers

<p>Hemoglobin in red blood cells (B)</p> Signup and view all the answers

<p>Insulin secretion from the pancreas (B)</p> Signup and view all the answers

<p>Alveoli (D)</p> Signup and view all the answers

<p>To sense changes in blood PCO2 and influence breathing rate (B)</p> Signup and view all the answers

<p>Glucagon triggers glycogen breakdown (A)</p> Signup and view all the answers

<p>Reabsorption of water and electrolytes (C)</p> Signup and view all the answers

<p>Villi and microvilli (C)</p> Signup and view all the answers

<p>Neutralizes acidic chyme with bicarbonate (D)</p> Signup and view all the answers

<p>It has a larger diameter but is shorter than the small intestine. (C)</p> Signup and view all the answers

<p>It contracts to release bile in response to fatty food. (A)</p> Signup and view all the answers

<p>Small intestine, large intestine (A)</p> Signup and view all the answers

<p>Trypsin, chymotrypsin, and pancreatic amylase (A)</p> Signup and view all the answers

<p>Produce vitamin K for blood clotting (A)</p> Signup and view all the answers

The process of breaking down food into usable nutrients for the body.

The small intestine is the primary location for absorbing nutrients from digested food.

Transportation of oxygen, nutrients, and waste products throughout the body.

Blood flows through arteries, capillaries, and veins, ultimately returning to the heart.

Carbohydrates are absorbed as simple sugars (monosaccharides).

Proteins are absorbed as individual amino acids.

The heart consists of four chambers that pump blood through the body.

Deoxygenated blood is pumped from the body to the lungs by the right ventricle of the heart.

The esophagus is a muscular tube that connects the mouth to the stomach. It uses peristalsis, wave-like muscle contractions, to move food down.

The stomach has 3 types of cells: Mucus-secreting cells (for lubrication), Parietal cells (secrete HCl), and Chief cells (secrete pepsinogen, an inactive protein-digesting enzyme)

Saliva moistens and lubricates food, helps you taste, and contains salivary amylase, an enzyme that starts starch digestion.

Swallowing starts voluntarily, but continues involuntarily. Your tongue pushes food back, the soft palate seals off the nose, and your larynx raises to block the airway.

Carnivores have pointed teeth that lack flat grinding surfaces, designed for tearing meat.

Herbivores have large flat teeth, perfect for grinding the cellulose cell walls found in plants.

Hydrochloric acid (HCl) denatures proteins in food, which makes it easier for pepsin to digest them.

Pepsin is an enzyme that breaks down proteins into smaller peptides, a key step in digestion.

A semi-liquid mixture of food and gastric juices that leaves the stomach.

A muscular valve at the bottom of the stomach that controls the flow of chyme into the small intestine.

The small intestine is divided into three sections: the duodenum, jejunum, and ileum.

Tiny finger-like projections called villi and microscopic projections called microvilli cover the small intestine, increasing the surface area for nutrient absorption.

The large intestine mainly absorbs water, electrolytes, and vitamin K, and prepares waste for elimination.

The pancreas secretes enzymes that break down proteins, carbohydrates, and fats into smaller molecules.

The liver produces bile, detoxifies harmful substances, and metabolizes ingested alcohol and drugs.

The gallbladder stores and concentrates bile, releasing it into the small intestine when needed.

Obtaining enough oxygen and eliminating excess carbon dioxide.

Gases diffuse across the membranes of respiratory organs, driven by concentration differences and solubility.

Tiny air sacs in mammalian lungs where gas exchange occurs.

The chest cavity expands due to muscle contractions, creating negative pressure that draws air into the lungs.

Chemosensitive neurons detect blood CO2 levels and send signals to the brain to adjust breathing rate.

Plasma.

Red blood cells responsible for oxygen transport.

The pigment in red blood cells that binds and transports oxygen.