A&P ii study guide two

List the structures of the alimentary canal. (MPESSLA)

• Mouth

• Pharynx

• Esophagus

• Stomach

• Small intestine

• Large intestine

• Anal canal/anus

List the accessory digestive organs. (TTSLGP)

• Teeth

• Tongue

• Salivary glands

• Liver

• Gallbladder

• Pancreas

what are the four specialized stomach cells

Mucous neck cells

parietal cells

chief cells

enteroendocrine cells

What do mucus neck cells produce?

Acidic mucus that helps protect the stomach lining.

What do parietal cells secrete?

Hydrochloric acid (HCl)

Intrinsic factor (needed for Vitamin B12 absorption)

What do chief cells secrete?

Pepsinogen (inactive pepsin)

Activated by HCl into pepsin

What do enteroendocrine cells secrete? (GHSSC)

• Gastrin

• Histamine

• Serotonin

• Somatostatin

• Cholecystokinin (CCK)

Which enzyme digests starch and carbohydrates?

Salivary amylase and pancreatic amylase.

Which enzyme digests proteins? (PTPCAD)

• Pepsin

• Trypsin

• Proteases

• Carboxypeptidase

• Aminopeptidase

• Dipeptidase

Which enzyme digests fats?

• Lingual lipase

• Gastric lipase

• Pancreatic lipase

Which enzyme digests lactose?

Lactase.

Which enzymes digest sucrose and maltose?

• Sucrase

• Maltase

List the pathway food takes through the digestive tract.

Mouth → Pharynx → Esophagus → Stomach → Duodenum → Jejunum → Ileum → Cecum → Ascending Colon → Transverse Colon → Descending Colon → Sigmoid Colon → Rectum → Anal Canal → Anus

What are the components of bile?

• Bile salts

• Bile pigments

• Cholesterol

• Neutral fats

• Phospholipids

• Electrolytes

What is the function of bile?

Emulsifies fats into small droplets to increase surface area for lipase.

List the four layers of the digestive tract.

1. Mucosa

2. Submucosa

3. Muscularis externa

4. Serosa

What are the three layers of the mucosa?

• Epithelium

• Lamina propria

• Muscularis mucosae

Function of rugae?

Allow stomach expansion.

Function of villi?

Increase surface area for nutrient absorption.

Function of microvilli?

Further increase absorptive surface area (brush border).

Function of haustra?

Allow mixing and slow movement of feces.

Function of the greater omentum?

Stores fat, supports abdominal organs, carries blood vessels, nerves, and lymphatics.

Function of the lesser omentum?

Connects the stomach to the liver.

Name the regions of the stomach.

• Cardia

• Fundus

• Body

• Pylorus

What stimulates the cephalic phase?

Sight, smell, taste, or thought of food.

What stimulates the gastric phase?

Stomach distension and proteins.

What stimulates the intestinal phase?

Chyme entering the duodenum.

What does gastrin do?

Stimulates HCl secretion and gastric motility.

What does secretin do?

Stimulates bicarbonate secretion and inhibits stomach activity.

What does CCK do?

stimulates pancreatic enzymes, gallbladder contraction, and causes satiety.

What does VIP do?

Inhibits stomach secretion and slows gastric emptying.

Segmentation vs. Peristalsis

Segmentation: Mixes food.

Peristalsis: Moves food forward.

Compare the digestive membranes.

• Parietal peritoneum = lines cavity

• Visceral peritoneum = covers organs

• Mesentery = suspends organs

• Greater omentum = fat apron

• Lesser omentum = connects liver and stomach

How does the stomach keep from digesting itself?

• Thick bicarbonate mucus

• Tight junctions

• HCl-impermeable lining

• Rapid epithelial replacement

Locate the cystic, hepatic, and pancreatic ducts.

• Hepatic duct → drains liver

• Cystic duct → drains gallbladder

• Common bile duct → formed by hepatic + cystic ducts

• Pancreatic duct joins common bile duct before entering the duodenum

label these

A- hepatic duct

B- bile duct

C- pancreatic duct

D- cystic duct

Micelles vs. Chylomicrons

Micelles

• Bile salt droplets

• Deliver lipids to intestinal cells

Chylomicrons

• Lipoproteins formed inside intestinal cells

• Transport absorbed fats through lymph

Front: What are the three stages of cellular respiration?

• Glycolysis

• Krebs Cycle

• Electron Transport Chain

What happens during glycolysis?

Occurs in cytoplasm.

Produces:

• 2 ATP

• 2 NADH

• 2 Pyruvate

What happens during the Krebs cycle?

Occurs in mitochondrial matrix.

Produces:

• 2 ATP

• 8 NADH

• 2 FADH₂

What happens during the Electron Transport Chain?

Uses NADH and FADH₂ to produce approximately 34 ATP using oxygen.

What are NADH and FADH₂?

Electron carriers that transport high-energy electrons to the ETC.

What is NAD⁺?

Oxidized electron carrier recycled to continue glycolysis.

ATP produced aerobically?

Approximately 38 ATP (theoretical maximum).

ATP produced anaerobically?

2 ATP.

Byproducts of fat metabolism?

Ketone bodies (may cause ketoacidosis).

Byproducts of protein metabolism?

Ammonia (NH₃), converted to urea.

List the lymphatic organs. (LTTSMP)

• Lymph nodes

• Tonsils

• Thymus

• Spleen

• MALT

• Peyer's patches

How is lymph moved?

• Skeletal muscle pump

• Respiratory pump

• Smooth muscle contraction

• One-way valves

Describe the two drainage routes.

Thoracic duct → left subclavian vein

Right lymphatic duct → right subclavian vein

Functions of the lymphatic system?

• Return fluid

• Return proteins

• Absorb fats

• Immune defense

Compare lymphatic and blood capillaries.

Lymphatic

• Dead-ended

• More permeable

• Mini-valves

• Collect proteins/pathogens

Blood

• Continuous circulation

• Less permeable

Humoral vs. Cell-mediated immunity

Humoral = B cells → antibodies

Cell-mediated = T cells → destroy infected cells

Functions of inflammation

• Limit infection

• Remove debris

• Promote tissue repair

Components of inflammation

• Macrophages

• NK cells

• Histamine

• Interferon

• Complement

• Pyrogens

Four types of T cells

• Helper (CD4)

• Cytotoxic (CD8)

• Regulatory

• Memory

Which T cell does HIV infect?

Helper T cell (CD4).

Compare VLDL, LDL, and HDL.

VLDL: Delivers triglycerides.

LDL: Delivers cholesterol ("bad").

HDL: Removes cholesterol ("good").

Absorptive vs. Postabsorptive state

absorptive

Absorptive

• Insulin

• Uses dietary nutrients

• Glycogenesis

• • Lipogenesis

post absorptive

Postabsorptive

• Glucagon

• Uses stored fuels

• Glycogenolysis

• Lipolysis

• • Gluconeogenesis

Four types of immunity with examples.

Natural Active: Chickenpox infection

Natural Passive: Maternal antibodies

Artificial Active: Vaccination

Artificial Passive: Antibody injection (immunoglobulin therapy)

lymph

fluid from capillaries headed back to circulary system

Vessel system

collects the interstitial fluid and returns it to the cardiovascular system.

functions of lymph

• Draining excess interstitial fluid at a rate of ~ 3 L/day

• Return leaked proteins to blood.

• lipid absorption

Capillaries

Dead ended, permeable capillaries, slightly larger than blood capillaries.

mini valves

big openings that allow proteins and water to enter

Lymph collecting vessels

• Similar to veins, but thinner, more permeable.

• Lots of internal one-way valves.

thoracic duct

rains lymph from lower body and upper left of body.

Drains into the left subclavian vein

right lymphatic duct

drains lymph from upper right of body

Drains into the right subclavian vein.

Lymph Transport

blood capillaries to interstitial space to lymphatic capillaries to lymph vessels to lymphatic ducts to subclavian veins

muscle pump

Movement of muscles squeezes vessels and forces lymph forward.

respiratory pump

Pressure changes during respiration pushes lymph forward (inhalation = less pressure in thoracic cavity then abdominal region)

rhythmical contractions of smooth muscle

• Fluid moves slowly, but activity increases speed.

• Inflamed areas benefit from massage and muscle contraction.

• Badly infected areas should be immobilized to decreased movement of materials and pathogens.

lymphoid cells

• lymphocytes (T, B, macrophages)

How do lymphoid cells fight pathogens

1. Directly killing them

2. Activating other immune cells

3. Phagocytize cell debris

lymphoid tissue

(reticular connective tissue): surveillance, lack a capsule.

Diffuse lymphatic tissue

scattered reticular tissue that is in the lamina propria of mucous membrane – lymphocytes cycle in and out.

lymphatic follicles

can form and go away as needed to fight local infections

nodes

1. 600 along the system, usually grouped.

2.Largest clusters in inguinal, axillary and cervical regions.

nodes function

1. Filter pathogens from the lymph.

2. Monitor the pathogens and activate the inflammatory response is necessary.

3. Immune system activation.

tonsils

Simplest lymphoid organ (5 total)

adenoid tonsils

on the posterior wall or nasopharanyx.

palatine tonsils

on the posterior regions of the oral cavity (tonsillectomy)

lingual tonsils

at the base of the tongue.

• Trap an enormous number of pathogens.

• Sacrificial lamb of the lymphatic system.

• Creates memory cells that fight common pathogens.

• Seldom last a life-time because it sees so many pathogens

thymus

important early in life, only lymphoid organ that does not DIRECTLY fight pathogens.

Houses T lymphocytes.

Spleen

site where lymph cells proliferate, receives huge blood supply.

Function of spleen

• Cleanses blood

• Removes old and defective RBCs

• Stores Platelets

White pulp

lymphatic tissue

red pulp

blood filled sinuses

MALT

mucosa associated lymphatic tissue in passages open to the exterior.

Peter patches

• located in the distal small intestine.

• set up to destroy harmful intestinal bacteria.

Metastasis

spread of disease from one area to another by way of the lymph system.

Innate immune system

(non-specific)

• Surface

• Internal

Adaptive immune system

(specific)

• Humoral (B-cell)

• Cellular (T-cell)

1st line of defense

integumentary (skin)

parts of the skin

• Keratin

• Enzymes

• Acidic level of pH of skin (3-5)

• Lysozymes in sweat

2nd line of defense

inflammation

signs of inflammation

redness

swelling

heat

pain

function of inflammation

• Limit the spread of the pathogen.

• Clean up damaged tissue.

• Tissue repair.