section 3 Flashcards
What is the process of filtration in the urinary system?
Blood passes through a filter that retains blood cells, proteins, and other large solutes but allows small molecules, ions, and urea to pass through.
What is reabsorption in the context of kidney function?
Selective ions and molecules are taken back into the bloodstream from the filtrate to maintain homeostasis.
What is secretion in the urinary system?
Select ions and end products of metabolism (e.g., K+, H+, NH3) that remain in the blood are added to the filtrate for removal from the body.
What is the nephron?
The nephron is the filtration unit of the metanephric kidney, consisting of structures that perform filtration, secretion, and absorption.
What is the function of the glomerular capsule (Bowman’s capsule)?
It is the initial filtration apparatus of the nephron and is located in the outermost region of the kidney.
List the important functions of the kidneys.
- Helps get rid of harmful substances
- Gets rid of waste
- Helps maintain pH of blood
- Maintains osmotic balance
What happens during the tension reflex response related to urination?
As the urinary bladder fills with urine, tension increases in its smooth muscle walls, leading to a reflex response that relaxes sphincter muscles at the entrance of the urethra.
What is the renal pyramid?
It is part of the kidney structure where the outer region is the cortex, and it leads to the renal pelvis.
What is the main goal of the collecting duct in the nephron?
To reabsorb more water, especially in response to antidiuretic hormone (ADH), which helps concentrate the urine before it is excreted.
What is countercurrent multiplication?
It involves a transmembrane protein which is a symporter, pushing one ion out while sending another ion in the opposite direction, causing water to be pushed out for reabsorption.
What role does saliva play in digestion?
Saliva contains enzymes that begin breaking down food.
What is the role of pepsin in the stomach?
Pepsin breaks down proteins and is stored as an inactive precursor, pepsinogen, which is activated by hydrochloric acid.
Where does fat digestion begin and end?
Fat digestion begins and ends in the intestines.
What enzyme is responsible for fat digestion?
Lipase, which is secreted by the pancreas.
What is the primary site of nutrient absorption in the digestive system?
Capillaries in the small intestine.
What is the main function of the large intestine?
It absorbs water and packages waste for expulsion from the body.
What is segmentation in digestion?
Mixing of digestive contents to enhance nutrient absorption.
What do sphincters do in the digestive tract?
Regulate movement through the digestive tract.
What are the gastric phases of digestion?
- Cephalic: brain prepares for digestion
- Gastric: stomach activity
- Intestinal: food moves to intestines
What do chief cells in the gastric glands secrete?
Pepsinogen, which is activated by HCl into pepsin for protein digestion.
What is the exocrine function of the pancreas?
Secretes digestive enzymes into the common bile duct to aid in digestion of lipids.
What is the endocrine function of the pancreas?
Produces insulin, which facilitates glucose uptake from the blood.
What is the primary function of the liver?
Responsible for metabolic processes, including converting stored sugars to glucose.
What is the duodenum?
The first section of the small intestine that acts as a buffer to neutralize stomach acid.
