The Abdomen 3 Flashcards

Question

How long in the anal canal? Surrounded by what?

Answer 1

The Anal Canal * About 4 cm in length * Surrounded by a thickened band of circular smooth muscle fibres * These smooth muscle fibres form the internal anal sphincter * The internal anal sphincter is surrounded by a band of skeletal muscle which forms the external anal sphincter

Answer 2

* **Carbohydrate metabolism** – maintaining a normal blood glucose level * **Lipid metabolism** – stores triglycerides breaks down fatty acids into acetyl coenzyme A etc hepatocytes synthesize cholesteral and use it to make bile salts etc * **Protein metabolism** – death would occur in a few days without this. * **Removal** of **drugs** and **hormone**s * **Excretion of bilirubin** – absorbed from blood and secreted into bile * **Synthesis of bile salts** – used in small intestine emulsification and absorption of lipids * **Storage** – glycogen, vitamins and minerals * **Phagocytosis** * **Activation of vitamin d**

Answer 3

Pancreas and biliary tree

Answer 4

The Biliary System * Bile is secreted by the liver * About 800 – 1000 ml are secreted each day * pH range 7.6 - 8.6

Answer 5

The Biliary System * The function of the biliary system is to store and concentrate bile until it is needed * Bile is transported from the liver to the small intestine along the common bile duct * If bile is not needed for digestion the sphincter of Oddi (sphincter of the hepatopancreatic ampulla) which is around the ampulla of Vater (hepatopancreatic ampulla) closes • •Bile backs up and overflows along the cystic duct into the gallbladder for storage

Answer 6

Pancreas connected to duodenum by the larger pancreatic duct (through the hepatopancreatic ampulla) and the smaller accessory duct (through the duct of Santorini)

Answer 7

Digital Subtraction Angiography

Answer 8

Oxygenated blood from the hepatic artery and deoxygenated (containing – newly absorbed nutrients, drugs and possibly microbes and toxins from the GI tract) from hepatic portal vein

Answer 9

The Spleen * Lies in left hypochondriac region of the abdomen * Lies between diaphragm and fundus of stomach * About 12 cm long, 7 cm wide and 3 – 4 cm thick * Largest single mass of lymphatic tissue

Answer 10

Functions 1. Phagocytosis 2. Erythropoiesis 3. Lymphopoiesis 4. Immune response 5. Erythrocyte storage

Answer 11

A form of **endocytosis** in which the cell **engulfs large solid** **particles**, such as worn-out cells, whole bacteria, or viruses. Only a few body cells, termed **phagocytes**, are able to carry out phagocytosis. Two main types of phagocytes are **macrophages**, located in many body tissues, and **neutrophils**, a type of white blood cell. Phagocytosis begins when the particle **binds to a plasma membrane receptor** on the phagocyte, causing it to extend **pseudopods**, projections of its plasma membrane and cytoplasm. Pseudopods **surround the particle** outside the cell, and the membranes fuse to **form a vesicle** called a **phagosome**, which enters the cytoplasm. The phagosome **fuses with one or more lysosomes**, and lysosomal enzymes **break down the ingested material**.

Answer 12

The **production of RBCs**, starts in the red bone marrow with a precursor cell called a **proerythroblast**. The proerythroblast **divides several times**, producing cells that begin to synthesize haemoglobin. Ultimately, a **cell** near the end of the development sequence **ejects its nucleus** and **becomes a reticulocyte**. Loss of the nucleus causes the center of the cell to **indent**, producing the red blood cell’s distinctive biconcave shape. Reticulocytes **retain some mitochondria, ribosomes, and endoplasmic reticulum**. They **pass from red bone marrow** into the **bloodstream** by **squeezing between the endothelial cells of blood capillaries**. Reticulocytes **develop** into mature red blood cells **within 1 to 2 days after their release** from red bone marrow. **In the early fetus**, erythropoiesis takes place in the **mesodermal cells of the yolk sac**. By the **third or fourth month**, erythropoiesis moves to the **spleen and liver.**

Answer 13

The generation of lymphocytes, one of the five types of white blood cell (WBC). It is more formally known as lymphoid hematopoiesis.

Answer 14

Nodes- Oval or bean shaped structures located along the length of lymphatic vessels. 1-25mm long, scattered throughout the body usually in groups eg in mammary glands, axillae and groin.

Answer 15

Flow – Arteries (blood plasma)\> Blood capillaries (blood plasma) \> Interstitial spaces (as interstitial fluid, then excess approx 3 litres per day) \> Lymphatic capillaries (lymph) \> Lymphatic ducts (lymph) \> Subclavian veins (blood plasma).

Answer 16

Lymph Flow Is due to: 1. •The pressure of fluid in the tissues 2. •Muscle action during movement – squeezing lymph vessels with the valves preventing backflow 3. •The pulsation of the arteries which also squeezes the lymph vessels 4. •Respiratory motion 5. •Contraction of smooth muscle in the larger vessels (under sympathetic control)

Answer 17

* Lymph flow is slow, about 2 – 4 litres a day passes through the thoracic duct into the venous system (contrast this with the cardiac output of about 5 litres per minute) * Lymph fluid passes through a series of regional lymph nodes before reaching the blood stream * Lymph fluid from the thyroid gland, oesophagus & parts of the liver passes directly into the thoracic duct * The cisterna chyli (or Cysterna chyli, receptaculum chyli) is a dilated sac at the lower end of the thoracic duct into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow.