The Digestive System the Renal System Spring 2016

IUB Dr. Mustafa H. Chowdhury 1

Biomedical Electronics

Lecture – 6

Spring 2016

Faculty

Dr. Mustafa Habib Chowdhury

The Digestive System

and

the Renal System

EEE 541

Spring 2016

There are at least three processes

involved in the digestive system:

(1) The movement of food through

the digestive tract.

(2) The secretion of digestive

juices.

(3) The absorption of the food

providing nutrients.

The digestive system provides

water, electrolytes, and nutrients to

the body when the food moves

along the digestive tract.

IUB Dr. Mustafa Chowdhury 2

The Digestive System EEE541_L6

Spring 2016



Spring 2016



Spring 2016

The mouth, also called the oral cavity is lined with mucous membrane. The tongue

palate (soft and hard), cheek, and lips are part of this cavity. It’s main function

include taste, the breakdown of food by mastication, and the chemical digestion of

food by the salivary enzyme. Saliva also lubricates the food and control bacteria.

The salivary glands consist of three pairs of glands: the parotid, the

submandibular, and the sublingual. They each secrete saliva into the oral cavity.

The parotid glands are the largest salivary glands and are located on both sides of

the face, in front and below the ears. The submandibular glands are located below

the parotid glands near the lower jaw. Sublingual glands are the smallest and are

located under the sides of the tongue.

The esophagus secretes mucus and transports food to the stomach. Smooth

muscle contractions (peristalsis) push the food through the esophageal sphincter.

The stomach is the upper part of the abdominal cavity, located below the

diaphragm. The stomach can be divided into an upper part (called the fundus), a

middle part (called the body), and a lower part (called the pylorus). Hydrochloric

acid and gastric juices are released in the mucus layers of the stomach walls.


Parts of the Digestive SystemSpring 2016


The liver is the largest organ of the body and is divided into left and right

lobes. The liver is an essential organ that transforms poisons into less harmful

substances. It stores excess carbohydrates as well as copper, iron and

several types of vitamins.

The gallbladder stores the bile and releases it into the small intestine. The

pancreas releases enzymes into the small intestine. Bile emulsifies fats and

enzymes break down fats, proteins and carbohydrates.

The intestinal tract (digestive tract) consist of the small intestine and the

large intestine. The small intestine consists of duodenum, and the ileum. Final

absorption of food occurs in the small intestine. The ileum empties the semi-

liquid food into the large intestine.

The large intestine consists of the ascending colon, the transverse colon, the

descending colon, the sigmoid colon, the rectum, and the anal canal. The

colons absorb water and nutrients and excrete food residue.

Parts of the Digestive SystemSpring 2016


The Renal System EEE541_L6

Spring 2016


The renal system consists of all the organs involved in formation and release

of urine. It includes the kidneys, ureters, bladder, and urethra.

The kidneys are bean-shaped organs, which help the body produce urine to

get rid of unwanted waste substances. When urine is formed, tubes called

ureters transport the urine to the urinary bladder, where it is stored and

excreted via the urethra. The kidneys are also important in regulating our

blood pressure and helping produce red blood cells.

The kidneys perform two major functions: (1) They excrete the end products

of body metabolism; (2) The control the concentration of body fluids.

The kidneys contain millions of nephrons. The nephrons form urine by three

processes: filtration by the glomerulus, re-absorption within the renal tubules,

and secretion by the tubular cells.

Parts of the Renal SystemSpring 2016


Parts of the NephronSpring 2016

• The typical pressures in different parts of

the nephron range from 100 mm Hg

before the glomerulus to 0 mm Hg at the

pelvis.

• The blood flow through both kidneys is

about 12 percent to 30 percent of the

cardiac output in a resting person. If the

cardiac output is 5,600 ml/min, then the

blood flow through the kidneys is about

1,200 ml/min.

• The important parts of a nephron are the

glomerulus, peritubular capillaries, vasa

recta, loop of Henle, and the collecting

duct.

EEE541_L6


Structure and Function of the NephronSpring 2016


Structure and Function of the NephronSpring 2016


Parts of the NephronSpring 2016

• The glomerulus filters water and dissolved

substances from the plasma of the blood.

There is an increased blood pressure in the

glomerulus that allows the filtration process.

Large proteins are not filtered.

• The filtrate is mostly water and the

dissolved substances are sodium,

potassium, calcium, magnesium, glucose,

urea, uric acid, and other negatively

charged ions .

• The process of reabsorption of water and

substances occurs throughout the renal

tubule. The pertibular capillaries transport

substances back into the blood. The

descending loop of Henle reabsorbs

water by osmosis, and the ascending

loop reabsorbs sodium, potassium, and

ions by active transport.

EEE541_L6

IUB Dr. Mustafa H. Chowdhury 13

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Documents

The Digestive System the Renal System Spring 2016