final exam A&P II

intraperitoneal

Organs located within the peritoneal cavity.

retroperitoneal

Organs located behind the peritoneum.

intraperitoneal organs

stomach, colon, liver, spleen,

retroperitoneal organs

ureter, duodenum, aorta, bladder, pancreas, kidneys

tissue lining outer wall of abdominal cavity

parietal peritoneum

serosa of stomach

visceral peritoneum

lining of outer wall of thoracic cavity

parietal pleura

attached to surface of heart

visceral pericardium (epicardium)

What is found between the visceral and parietal layers of a serous membrane?

serous fluid

Structures that food passes through from the mouth to the anus

1-Mouth (Oral Cavity)

2-Pharynx (Oropharynx, Laryngopharynx)

3-Esophagus

4-Stomach

5-Small Intestine

6-Large Intestine

7-Rectum

8-Anus (via Anal Canal)

accessory structures of the GI tract

1-Teeth

2-Tongue

3-Salivary Glands (Parotid, Submandibular, Sublingual)

4-Liver

5-Gallbladder

6-Pancreas

The four histological layers of organs in the GI, respiratory, urinary, and reproductive tracts

1-Mucosa (innermost)

2-Submucosa

3-Muscularis (or Muscularis Externa)

4-Serosa or Adventitia (outermost)

Name the three parts of the mucosa

1-Epithelium (lines the lumen)

2-Lamina Propria (loose connective tissue)

3-Muscularis Mucosae (thin layer of smooth muscle)

When does an organ have an adventitia instead of a serosa?

An organ has an adventitia when it is retroperitoneal

Explain the process of peristalsis

Wave-like smooth muscle contractions that propel food through a tubular organ.

which part of the autonomic nervous system increases peristalsis in GI tract

parasympathetic nervous system

Which tissues are necessary for peristalsis?

Smooth muscle

Organs that undergo peristalsis in the Digestive System?

Esophagus, Stomach, Small Intestine, Large Intestine.

Amylase function/origin?

Digests starch; Origin: Salivary glands, Pancreas.

Pepsin function/origin?

Digests proteins; Origin: Stomach.

Which enzymes are released as zymogens (proenzymes)?

Pepsin (as Pepsinogen, activated by HCl) and Trypsin/Chymotrypsin (activated by Enterokinase)

Is bile an enzyme? What is its function?

No, it is not an enzyme. Function is to emulsify fats.

Key structure where bile and pancreatic ducts merge before entering the small intestine?

Hepatopancreatic Ampulla.

Main chemical digestion in the Stomach?

Protein (Pepsin).

Main chemical digestion in the Small Intestine?

All (Carbohydrates, Proteins, and Lipids).

Main mechanical digestion in the Small Intestine?

Segmentation (mixing).

Where does the majority of absorption occur?

Small Intestine (Jejunum).

Name the three key surface area modifications in the small intestine.

Circular folds, Villi, Microvilli.

Form of carbohydrates/proteins when absorbed?

Monosaccharides and Amino acids.

Vessel that carries absorbed monosaccharides and amino acids to the liver?

Hepatic Portal Vein.

What is a chylomicron?

A lipoprotein particle that transports absorbed lipids into the lymphatic system.

Where do fats go once they are absorbed?

They are packaged into chylomicrons, enter the lacteals in the villi, and travel through the lymphatic system before entering the bloodstream near the heart.

Name two other types of lipoproteins and their functions.

1- LDL (Low-Density Lipoprotein): Transports cholesterol from the liver to peripheral tissues ("bad cholesterol").

2- HDL (High-Density Lipoprotein): Transports excess cholesterol from peripheral tissues back to the liver ("good cholesterol").

Describe the function of the Liver.

Produces bile (for fat emulsification), processes absorbed nutrients, detoxifies blood

What is the function of the Salivary Gland?

Produces saliva which contains amylase for carbohydrate digestion and lubricates food for swallowing.

What is the function of the Gallbladder?

Stores and concentrates bile.

What is the function of the Pancreas?

Produces digestive enzymes (lipase, amylase, proteases) and bicarbonate to neutralize stomach acid in the duodenum.

Why is it important that stomach juice is acidic?

1. Activates the enzyme pepsinogen into active pepsin.

2. Denatures proteins, making them easier to digest.

3. Kills most ingested bacteria.

What nervous systems control digestion?

Enteric nervous system and Autonomic nervous system.

What is the intrinsic nervous system of the GI tract called?

Enteric Nervous System (ENS).

Which part of the ANS increases motility and secretion in the GI tract?

Parasympathetic Nervous System.

Which cranial nerve is involved in GI regulation?

Vagus Nerve (Cranial Nerve X).

What is the function of Cholecystokinin (CCK) and where is it made?

Function: Stimulates the gallbladder to contract (releasing bile) and the pancreas to secrete enzymes.

Made in: Small Intestine (Duodenum/Jejunum).

What is the function of Secretin and where is it made?

Function: Stimulates the pancreas and liver to secrete bicarbonate-rich fluid to neutralize chyme.

Made in: Small Intestine (Duodenum).

What is the function of Gastrin and where is it made?

Function: Stimulates stomach chief cells and parietal cells to secrete HCl and pepsinogen. Made in: Stomach (G-cells).

What is the primary function of the large intestine regarding absorption?

Primarily absorbs water and electrolytes.

What is the function of colonic bacteria (Gut Flora)?

They digest residual fiber/carbohydrates and synthesize essential Vitamins K and some B vitamins.

What is the process of defecation?

Mass movements push feces into the rectum, stimulating stretch receptors, triggering a reflex contraction of the rectum and relaxation of the internal anal sphincter. Defecation occurs when the external anal sphincter is consciously relaxed.

What are enzymes?

Biological catalysts that speed up specific chemical reactions without being consumed.

How does an enzyme differ from a hormone?

A hormone is a chemical signal transported in the blood to target cells, regulating physiological processes.

What type of organic compound are enzymes typically?

Proteins.

Why are enzymes specific to one type of reaction?

Due to their specific 3D structure, only the correct substrate can fit into the enzyme's active site.

Why are enzymes active at an optimal pH and temperature range?

Extreme pH or temperature can denature the enzyme's protein structure, destroying the active site.

What is the overall reaction for cellular respiration?

C₆H₁₂O₆ + 6O₂ → 6CO₂ +6H₂O + 38ATP + heat

What does 'oxidation of glucose' mean?

It is the complete breakdown of the glucose molecule, releasing energy by removing hydrogen atoms (electrons) and combining them with oxygen.

Which hormone influences the rate of cellular respiration?

Thyroid Hormone (regulates body metabolic rate).

Is cellular respiration anabolic, catabolic, or both?

Primarily Catabolic (breaking down glucose into smaller molecules, CO₂ and H₂O).

Steps of Glycolysis

Glucose -> 2 pyruvic acids, 2NADH, 2ATP

Where does glycolysis occur?

cytoplasm

Steps of krebs cycle

2 acetyl-CoA -> 6NADH, 2FADH, 2ATP

where does krebs occur

mitochondrial matrix

Steps of Electron Transport Chain

10NADH, 2FADH2 -> 34ATP, H2O

Is the conversion of Pyruvic Acid to Acetyl CoA aerobic or anaerobic?

Aerobic (requires oxygen, as it must occur in the mitochondria).

Is the conversion of Pyruvic Acid to Acetyl CoA reversible?

No (Acetyl CoA cannot be converted back to Pyruvic Acid).

Can Acetyl CoA be converted to pyruvic acid?

No, because the reaction is irreversible.

When does ketogenesis occur?

when Acetyl CoA accumulates often from low carbohydrates, starvation, or diabetes.

What is the role of Acetyl CoA in ketogenesis?

Acetyl CoA is diverted to make ketone bodies

What is the significance of niacin in cellular respiration?

Niacin is necessary to synthesize NAD+.

What is NADH and its role in cellular respiration?

NADH is the reduced form of NAD+, acting as an electron carrier that delivers high-energy electrons to the Electron Transport Chain to drive ATP synthesis.

What is the process of making ATP from glucose under anaerobic conditions?

Glycolysis occurs in the cytoplasm, producing 2 ATP and Pyruvic Acid, which is converted into Lactic Acid to regenerate NAD+, allowing glycolysis to continue.

How many ATP are formed anaerobically?

2 ATP per glucose molecule.

What is Gluconeogenesis and what hormone promotes it?

Gluconeogenesis is the synthesis of new glucose from non-carbohydrate sources. Promoted by Glucagon and Cortisol.

What is Glycogenesis and what hormone promotes it?

Glycogenesis is the synthesis of glycogen from excess glucose. Promoted by Insulin.

What is Glycogenolysis and what hormone promotes it?

Glycogenolysis is the breakdown of glycogen back into glucose. Promoted by Glucagon and Epinephrine.

How can proteins and amino acids be used to make ATP?

Amino acids are deaminated, and is converted into Pyruvate, Acetyl CoA, or Krebs Cycle intermediates, allowing entry into cellular respiration to produce ATP.

Why is deamination necessary when converting amino acids to glucose or ATP?

The amine group is toxic and must be removed before the carbon skeleton can be metabolized.

What excretory product does the liver produce when deaminating amino acids?

Urea.

How is urea eliminated from the body?

Urea travels through the blood to the kidneys, which filter it and excrete it in urine.

Why does the metabolism of fats lead to more ATP than glucose?

Fatty acids undergo beta-oxidation to produce a large number of Acetyl CoA molecules, which yield more NADH and FADH2 than a single glucose molecule.

Why are ketones formed when fat is broken down for ATP?

Excess Acetyl CoA is converted to ketone bodies when glucose levels are low, to keep the Krebs Cycle running.

Why can't fatty acids be converted into glucose?

The primary breakdown product of fatty acids is Acetyl CoA, which can't be converted into glucose bc the reaction is irreversible

What are the functions of the liver concerning clotting?

Synthesizes most clotting factors (e.g., fibrinogen, prothrombin).

What are the functions of the liver concerning urea?

Converts toxic ammonia (from amino acid deamination) into urea for excretion.

What are the functions of the liver concerning vitamin storage?

Stores fat-soluble vitamins A, D, E, K and vitamin B12.

What are the functions of the liver concerning normal growth?

Produces somatomedins (or insulin-like growth factors, IGFs) in response to growth hormone.

What are the functions of the liver concerning blood pressure?

Synthesizes angiotensinogen, a precursor for the hormone angiotensin II, which regulates blood pressure.

What are the functions of the liver concerning lipoproteins?

Synthesizes and regulates various lipoproteins (VLDL, HDL) for fat transport.

What are the functions of the liver concerning digestion?

Produces bile for fat emulsification.

What are the functions of the liver concerning toxic substances?

Detoxifies the blood by chemically altering substances like alcohol, drugs, and hormones.

What are the functions of the liver concerning red blood cells (RBCs)?

Breaks down old or damaged RBCs.

What does the liver do concerning bilirubin?

plays a crucial role in the metabolism of bilirubin

Why does the liver make bilirubin?

Bilirubin is a toxic yellow pigment from the breakdown of heme in worn-out red blood cells, and the liver processes it for excretion.

Name three important plasma proteins.

Albumin, Globulins, Fibrinogen (or Prothrombin).

What is the important function of plasma proteins concerning Immunity?

Globulins (specifically gamma globulins or antibodies) provide immune defense.

What is the important function of plasma proteins concerning Osmotic Pressure?

Albumin is the primary protein responsible for maintaining blood colloid osmotic pressure.

What is the important function of plasma proteins concerning Clotting?

Fibrinogen and Prothrombin are essential for blood coagulation.

What does it mean to say that blood osmotic pressure is high?

It means the concentration of solutes (primarily Albumin) in the blood plasma is high, causing water to move from the tissues into the blood via osmosis.

Where are red blood cells, white blood cells, and platelets made?

All are made in the Red Bone Marrow via hematopoiesis.

What is erythropoietin (EPO)?

A hormone that stimulates the production of red blood cells (erythrocytes).

Which organs make EPO and under what conditions?

Primarily the Kidneys (and some by the liver) in response to Hypoxia (low blood oxygen levels).