Digestive System Anatomy Quiz

Questions and Answers

What are the two divisions of the skeleton?

Axial skeleton and appendicular skeleton

Name an example of a long bone.

Humerus

Name an example of a short bone.

Trapezoid

Name an example of a flat bone.

Sternum Signup and view all the answers

Name an example of a sesamoid bone.

Patella Signup and view all the answers

Name an example of an irregular bone.

Vertebra Signup and view all the answers

What do the cranial bones collectively protect?

The brain Signup and view all the answers

Name the four major facial bones.

Nasal, zygomatic, maxilla, mandible Signup and view all the answers

The vertebral column allows multidirectional movement of the torso.

True Signup and view all the answers

What are the three functions of the paranasal sinuses?

Reduce weight of the skull, help to resonate vocal sounds, warm and humidify air. Signup and view all the answers

Describe the function of intervertebral discs.

They absorb compressive force and permit movement of the vertebral column. Signup and view all the answers

What do true ribs attach to?

Sternum via the costal cartilage Signup and view all the answers

What is the function of the clavicle?

Transmits mechanical force from the upper limbs to the trunk. Signup and view all the answers

What are the two main types of bone tissue?

Compact bone and spongy bone Signup and view all the answers

Define osteoporosis.

A disease in which bone resorption by osteoclasts exceeds bone deposit by osteoblasts. Signup and view all the answers

What happens to bone mass over the lifespan.

From birth to adolescence, bone deposit exceeds resorption; in later life, bone resorption may exceed deposit. Signup and view all the answers

Describe how skeletal muscle contraction occurs.

Muscle fibers contract when stimulated by an action potential, leading to the sliding of actin and myosin filaments. Signup and view all the answers

What neurotransmitter causes skeletal muscle contraction?

Acetylcholine (Ach) Signup and view all the answers

What are the functions of the lymphatic system?

Drain excess interstitial fluid, transport dietary lipids, facilitate immune responses. Signup and view all the answers

What are the cells of lymph nodes?

B cells, T cells, macrophages Signup and view all the answers

Where do B and T cells mature?

B cells mature in the bone marrow, T cells mature in the thymus Signup and view all the answers

Name three areas of lymphatic nodules.

Peyer's patches, appendix, tonsils Signup and view all the answers

What are the functions of the spleen?

Removes damaged blood cells, stores platelets, produces blood cells during fetal life Signup and view all the answers

Describe the anatomical position of the spleen.

It is located in the left hypochondriac region, between the stomach and diaphragm. Signup and view all the answers

What is the difference between cancerous nodes and infected nodes?

Cancerous nodes are firm, enlarged, non-tender, and fixed; infected nodes are soft, enlarged, tender, and moveable. Signup and view all the answers

Which cells are involved in phagocytosis?

All of the above Signup and view all the answers

What is immunity?

The capacity of the immune system to defend against infections Signup and view all the answers

What type of immunity involves direct exposure to a microbe?

Natural, active Signup and view all the answers

What are the types of acquired immunity?

Natural, active; Natural, passive; Artificial, active; Artificial, passive Signup and view all the answers

What is selective toxicity?

The ability to kill a microbe without harming the patient. Signup and view all the answers

What is antibiotic resistance?

The ability of microbes to resist antimicrobial agents Signup and view all the answers

Bactericidal means it directly kills bacteria, whereas __________ inhibits the growth of bacteria.

bacteriostatic Signup and view all the answers

List four undesirable responses of the immune system.

Hypersensitivity reaction, autoimmune disorder, immuno-compromised patient, attack against transplanted tissues Signup and view all the answers

Name and label all organs of the digestive tract in the correct sequence from when food enters the mouth to the exit from the body.

Mouth, pharynx, oesophagus, stomach, pyloric sphincter, duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, anus. Signup and view all the answers

Name and describe the nine regions and four quadrants of the abdominopelvic cavities.

Regions include: Right Hypochondriac, Epigastric, Left Hypochondriac, Right Lumbar, Umbilical, Left Lumbar, Right Iliac, Hypogastric, and Left Iliac. Quadrants: Right Upper Quadrant, Left Upper Quadrant, Right Lower Quadrant, Left Lower Quadrant. Signup and view all the answers

Name and describe the six digestive system processes.

Ingestion, Propulsion, Mechanical Digestion, Chemical Digestion, Absorption, and Defecation. Signup and view all the answers

Name the four layers of the digestive tract in the correct sequence from innermost to outer layer.

Mucosa, Submucosa, Muscularis, Serosa. Signup and view all the answers

Describe the function of each layer of the digestive tract.

Mucosa - surrounds the lumen, protects and secretes; Submucosa - supports mucosa and contains nerves; Muscularis - responsible for peristalsis and segmentation; Serosa - provides a partition between internal organs and abdominal cavity. Signup and view all the answers

Name the three layers of the peritoneum in the correct sequence, deep to superficial.

Visceral Layer, Peritoneal Layer, Parietal Layer. Signup and view all the answers

State four functions of the tongue.

Tastes, Manipulates food for chewing, Aids swallowing, Articulates speech. Signup and view all the answers

State the health risks associated with tooth and gum disease.

Dental caries caused by plaque, gum inflammation, increased risk of heart disease and stroke. Signup and view all the answers

State two functions of saliva.

Softens, moistens and dissolves food; Cleans mouth and teeth. Signup and view all the answers

Name the four contents of saliva and give a function for each.

Water - dissolves food; Salivary Amylase - digests starch; Mucus - lubricates food; Lysozyme - helps destroy bacteria. Signup and view all the answers

State two situations that would reduce the production of saliva.

Dehydration; Stimulation of the sympathetic nervous system. Signup and view all the answers

Describe what would happen if saliva was not produced.

Difficulty chewing, moistening, and swallowing; saliva is required to initiate chemical digestion. Signup and view all the answers

State the location and function of the epiglottis.

Covers the larynx; directs food and fluids from the oropharynx to the oesophagus. Signup and view all the answers

State the function of the oesophagus.

Secretes mucus and transports food and fluid to the stomach through peristalsis. Signup and view all the answers

Define dysphagia.

Difficulty swallowing. Signup and view all the answers

State the major function of the stomach.

To compress, knead and mix food beginning the process of digestion. Signup and view all the answers

State the function of stomach juice and the specific function of HCl and mucus in the stomach.

HCl kills microbes and aids digestion; Mucus protects the stomach wall from damage. Signup and view all the answers

Describe the homeostatic imbalances that can occur with prolonged or severe vomiting.

Can lead to dehydration and disrupt electrolyte and pH balance. Signup and view all the answers

Describe the anatomical position of the liver.

Occupies most of the Right Hypochondriac and Epigastric regions. Signup and view all the answers

State the seven functions of the liver.

Bile production, phagocytosis, processing nutrients, storage, formation of clotting factors, detoxification, heat production. Signup and view all the answers

Name the two blood vessels that supply the liver & the vein that exits the liver.

Supply = Hepatic Portal Vein & Hepatic Artery; Exiting = Hepatic Vein. Signup and view all the answers

State the function of the stellate reticuloendothelial (Kupffer’s) cells.

Remove debris, bacteria, and worn-out blood cells from the blood. Signup and view all the answers

Name the cells that produce bile.

Hepatocytes. Signup and view all the answers

Name the structure that stores bile and describe the main function of bile.

Gallbladder; neutralizes acid from the stomach and emulsifies fat. Signup and view all the answers

Describe the anatomical position of the pancreas.

Posterior to the stomach in the epigastric region. Signup and view all the answers

State one exocrine function of the pancreas.

Produce pancreatic juice which flows into the duodenum. Signup and view all the answers

Name the three portions of the small intestine in correct sequence.

Duodenum, Jejunum, Ileum. Signup and view all the answers

Describe two functions of the small intestine.

Chemical digestion and mechanical digestion. Signup and view all the answers

Name the four structural features of the small intestine and state their overall function.

Circular folds, Villi, Microvilli, Length. Signup and view all the answers

State the function of intestinal juice.

Contains enzymes that convert disaccharides to monosaccharides and peptides into amino acids. Signup and view all the answers

State four functions of the large intestine.

Absorbs water, produces vitamins, moves contents to the rectum, forms feces. Signup and view all the answers

Name the main cranial nerve involved in regulating the digestive system.

The vagus nerve (CNX). Signup and view all the answers

State the autonomic system that stimulates the digestive system.

The enteric nervous system. Signup and view all the answers

Name the two main reflexes that affect motility in the intestines.

Gastroileal Reflex and Gastrocolic Reflex. Signup and view all the answers

Describe the defecation reflex using the components of the reflex arc.

Stimulus: faeces distending the rectum; Control center: sacral spinal cord; Effectors: colon & rectal wall contract; Response: elimination of faeces. Signup and view all the answers

Name the six types of nutrients.

Water, Carbohydrates, Lipids, Proteins, Minerals, Vitamins. Signup and view all the answers

State the major source of energy for the body.

Carbohydrates. Signup and view all the answers

Name the three monosaccharides that are absorbed.

Glucose, Fructose, Galactose. Signup and view all the answers

State the end products of digestion of triglycerides.

Monoglyceride and 2 fatty acids. Signup and view all the answers

State five types of lipids and describe the major function for each type.

Fatty Acid - energy; Triglyceride - energy storage; Phospholipids - cell membranes; Steroids - hormones; Prostaglandins - local hormones. Signup and view all the answers

State the overall function of lipoproteins.

To transport lipids in the blood. Signup and view all the answers

Name the three different types of lipoproteins and describe the specific function for each type.

HDL - collects excess cholesterol; LDL - delivers cholesterol to tissues; VLDL - delivers triglycerides to adipose tissue. Signup and view all the answers

Describe the clinical significance of raised LDL.

High LDL can lead to cholesterol buildup in arteries, increasing the risk of heart disease and stroke. Signup and view all the answers

State the end product of the digestion of proteins and describe the overall function of these units.

Amino acids; used to manufacture proteins in the body. Signup and view all the answers

Name seven different types of proteins and give one function for each type.

Structural protein - provides strength; hormones - regulate body functions; contractile protein - muscle movement; antibodies - immune defense; hemoglobin - oxygen transport; enzymes - accelerate reactions. Signup and view all the answers

Name the four fat-soluble vitamins and describe one main function of each.

Vitamin A - vision; Vitamin D - calcium absorption; Vitamin E - antioxidant; Vitamin K - blood clotting. Signup and view all the answers

Explain the function of antioxidant vitamins.

They protect cells from damage caused by free radicals. Signup and view all the answers

Name and describe a main function for the minerals listed in the lecture notes.

Calcium - bone health; Iron - oxygen transport; Potassium - fluid balance. Signup and view all the answers

Define the three different drug names.

Chemical Name - describes composition; Generic Name - used for prescriptions; Trade Name - marketed name. Signup and view all the answers

Define the term pharmacodynamics.

what the drug does to the body Signup and view all the answers

Define the terms agonist and antagonist.

Agonist - activates a receptor; Antagonist - blocks a receptor. Signup and view all the answers

Define the term pharmacokinetics.

How the body affects a specific drug after administration. Signup and view all the answers

Name and describe the four pharmacokinetic processes in correct sequence.

Absorption - medication into the blood; Distribution - movement to tissues; Metabolism - chemical modification; Excretion - removal from the body. Signup and view all the answers

State five ways that drugs can be excreted.

Bile, Faeces, Expired air, Sweat, Breast milk. Signup and view all the answers

Explain hepatic first pass effect.

Orally administered drugs are metabolized by the liver before entering systemic circulation. Signup and view all the answers

Explain drug bioavailability.

the amount of drug that has an active effect enters the systemic circulation Signup and view all the answers

State six functions of the skeletal system.

Support, Protection, Movement, Storage, Blood cell production. Signup and view all the answers

Study Notes

Digestive System Overview

Digestive tract sequence: Mouth → Pharynx → Oesophagus → Stomach → Pyloric Sphincter → Duodenum → Jejunum → Ileum → Cecum → Ascending Colon → Transverse Colon → Descending Colon → Sigmoid Colon → Anus.

Abdominopelvic Regions and Quadrants

Nine regions: Right Hypochondriac, Left Hypochondriac, Epigastric, Right Lumbar, Left Lumbar, Umbilical, Right Iliac, Left Iliac, Hypogastric.
Four quadrants: Right Upper Quadrant, Left Upper Quadrant, Right Lower Quadrant, Left Lower Quadrant. Each quadrant contains various organs including intestines, liver, pancreas, and reproductive organs.

Digestive System Processes

Ingestion: Taking food into the mouth.
Propulsion: Moving food through the digestive tract via swallowing and peristalsis.
Mechanical Digestion: Physical breakdown of food (chewing, churning in the stomach).
Chemical Digestion: Breakdown of food molecules into their building blocks.
Absorption: Nutrient transfers into blood or lymph from the digestive tract.
Defecation: Elimination of indigestible substances from the body.

Layers of the Digestive Tract

Mucosa: Epithelium; protects and secretes.
Submucosa: Dense, irregular connective tissue; supports mucosa and contains nerves.
Muscularis: Circular and longitudinal muscle; responsible for peristalsis and segmentation.
Serosa: Areolar connective tissue; separates internal organs from the abdominal cavity.

Peritoneum Layers

Visceral Layer: Covers organs.
Peritoneal Layer: Contains serous fluid.
Parietal Layer: Lines the abdominopelvic cavity.

Tongue Functions

Tastes food.
Manipulates food for chewing.
Aids in swallowing.
Articulates speech.

Tooth and Gum Disease Risks

Dental caries: Caused by bacterial plaque.
Plaque formation can lead to chronic inflammation, increasing heart disease and stroke risks.

Saliva Functions

Softens and moistens food.
Cleanses the mouth and teeth.
Composition: Water (solvent), Salivary Amylase (starch digestion), Mucus (lubrication), Lysozyme (bacterial destruction).
Reduced saliva production: Occurs with dehydration or sympathetic nervous system stimulation.

Epiglottis and Oesophagus Functions

Epiglottis: Covers the larynx, directing food into the oesophagus.
Oesophagus: Secretes mucus and transports food to the stomach via peristalsis.

Stomach Functions

Compresses, kneads, and mixes food to initiate digestion.
Stomach juice: HCl (kills microbes) and mucus (protects stomach lining).

Homeostatic Imbalances

Prolonged vomiting can cause dehydration and electrolyte/pH imbalance.

Liver Position and Functions

Anatomical position: Right Hypochondriac and Epigastric regions.
Functions include bile production, RBC phagocytosis, nutrient processing, storage, clotting factor production, detoxification, and heat production.

Blood Flow to the Liver

Supplied by: Hepatic Portal Vein and Hepatic Artery.
Exits via: Hepatic Vein.

Bile Production and Function

Produced by: Hepatocytes.
Stored in: Gallbladder.
Main functions: Neutralizes stomach acid, emulsifies fats, removes waste.

Pancreas Position and Function

Located posterior to the stomach in the epigastric region.
Exocrine function: Produces pancreatic juice for digestion.

Small Intestine Structure and Function

Portions: Duodenum, Jejunum, Ileum.
Functions: Chemical digestion and mechanical digestion (via peristalsis).

Small Intestine Features

Circular folds: Slow chyme transit for absorption.
Villi: Contain blood capillaries and lacteals for fat absorption.
Microvilli: Secrete enzymes; increase absorption surface area.

Large Intestine Functions

Completes absorption of water/ions.
Produces Vitamins B and K.
Facilitates movement of contents and formation of feces.

Digestive Tract Control

Vagus nerve (CNX) regulates the digestive system.
Enteric nervous system controls gastric secretion and motility.
Stress may inhibit GI function due to sympathetic activation.

Motility Reflexes

Gastroileal Reflex: Triggered by stomach distension, increases peristalsis to caecum.
Gastrocolic Reflex: Initiated by stomach distension, promotes mass peristalsis in the colon.

Defecation Reflex

Stimulus: Rectal distension from feces.
Control center: Sacral spinal cord.
Effectors: Lower colon contraction, relaxation of internal anal sphincter.

Ageing Effects on Digestive System

Slower digestion.
Decreased enzyme production.
Reduced blood flow to organs.
Changes in taste and appetite.
Slower peristalsis.

Nutrients Overview

Six types: Water, Carbohydrates, Lipids, Proteins, Minerals, Vitamins.
Major energy source: Carbohydrates.
Monosaccharides absorbed: Glucose, fructose, galactose.
Triglyceride digestion produces: Monoglyceride and 2 fatty acids.

Lipid Types and Functions

Fatty Acid: Energy production, triglyceride synthesis.
Triglyceride: Insulation, energy storage.
Phospholipids: Cell membrane structure.
Steroids: Precursor for various hormones.
Prostaglandins: Mediators of inflammation and pain responses.

Lipoproteins Overview

Function: Lipid transport in blood.
Types: HDL (cholesterol removal), LDL (cholesterol delivery), VLDL (triglyceride delivery).
High LDL levels correlate with increased cardiovascular risk.

Protein Digestion

End product: Amino acids used for protein synthesis.
Protein types include structural, hormonal, contractile, antibodies, hemoglobin, enzymes, neurotransmitters.

Fat-Soluble Vitamins

A (vision), D (calcium metabolism), E (antioxidant), K (blood clotting).

Antioxidant Vitamins Function

Protect cells from oxidative damage.

Mineral Functions Overview

Essential for various bodily functions including bone health, nerve conduction, and metabolic reactions.

Pharmacology Overview

Drug Names: Chemical name, Generic name, Trade name (marketed name).
Pharmacodynamics: Study of drug interaction and response.
Agonist vs Antagonist: Agonist activates; antagonist deactivates receptors.
Pharmacokinetics: Study of body’s effect on drugs (absorption, distribution, metabolism, excretion).

Pharmacokinetic Processes

Absorption: Medication passage into bloodstream, influenced by blood flow and surface area.
Distribution: Drug movement from blood to tissues, affected by blood supply and binding.
Metabolism: Chemical modification of drugs, primarily in the liver.
Excretion: Drug removal from the body via various routes.

Drug Excretion Routes

Drugs can be excreted through bile, feces, expired air, sweat, and breast milk.

Hepatic First Pass Effect

Orally taken drugs undergo metabolism in the liver before entering systemic circulation, affecting bioavailability.

Drug Bioavailability

Refers to the proportion of a drug that enters circulation; IV drugs are 100% bioavailable due to bypassing first-pass metabolism.

Musculoskeletal System Functions

Support and framework.
Protects vital organs.
Assists movement.
Mineral storage.
Houses red bone marrow for blood cell production.

Skeleton Divisions

Axial Skeleton: Provides support/protection (skull, vertebral column).
Appendicular Skeleton: Facilitates movement (limbs and girdles).

Bone Types and Examples

Long (Humerus), Short (Trapezoid), Flat (Sternum), Sesamoid (Patella), Irregular (Vertebra).

Cranial and Facial Bones

Cranial: Frontal, occipital, temporal, parietal; protect the brain.
Facial: Nasal, zygomatic, maxilla, mandible; framework for face and cavities for sensory organs.

Paranasal Sinuses Functions

Reduce skull weight.
Assist in vocal resonance.
Warm and humidify inhaled air.

Vertebral Column Functions

Allows multi-directional torso movement.
Supports trunk weight transfer to lower limbs.
Protects spinal cord and provides muscle attachment points.### Vertebral Column and Curves
Five sections: Cervical (7 vertebrae), Thoracic (12), Lumbar (5), Sacrum, Coccyx
Normal curves: Cervical, Thoracic, Lumbar, Sacral Curves

Spinal Abnormalities

Scoliosis: Abnormal lateral curvature, typically in the thoracic region
Kyphosis: Exaggerated thoracic curve characterized by a hunched back
Lordosis: Increased lumbar curvature, often leading to an arched lower back

Vertebrae Structure and Features

Vertebra components: Body, vertebral arch, processes for muscle and ligament attachment
Vertebral foramen: Contains the spinal cord
Intervertebral foramen: Contains spinal nerves

Intervertebral Discs

Located between vertebrae
Functions: Absorb compressive forces, allow vertebral column movement

Thoracic Cage

Protects heart, lungs, great blood vessels
Supports shoulder girdles and upper limbs
Provides muscle attachment points for the neck, back, chest, and shoulders

Ribs

Total ribs: 24; 1-7 are true ribs (attached), 8-10 are indirectly attached, 11 & 12 are floating
True ribs connect to the sternum via costal cartilage; floating ribs have cartilage embedded in lateral body wall muscles

Clavicle and Scapula Functions

Clavicle: Transmits mechanical force from upper limbs to trunk
Scapula: Provides attachment points for muscles; glenoid cavity articulates with humerus for shoulder mobility

Upper Limb Bones

Upper limb bones (proximal to distal): Humerus, Radius, Ulna, Carpals, Metacarpals, Phalanges

Pelvis

Functions: Supports vertebral column and abdominal organs
Joints: Pubic symphysis (anterior), Sacroiliac (posterior)

Lower Limb Bones

Lower limb bones (proximal to distal): Femur, Patella, Tibia, Fibula, Tarsals, Metatarsals, Phalanges
Calcaneus: Located at the heel

Long Bone Structure

Components: Diaphysis, epiphysis, periosteum
Periosteum functions: Protects bone, attachment for ligaments/tendons, nourishes bone tissue, aids in fracture repair

Bone Tissue Types

Compact Bone: External surface of bones; contains osteons for strength
Spongy Bone: Inside bones and ends of long bones; consists of trabeculae housing bone marrow

Cartilage Types

Articular Cartilage: Inside joint cavities; reduces friction and allows smooth movement
Fibrocartilage: In intervertebral discs and pubic symphysis; strength and compressibility

Bone Tissue Components

Bone tissue consists of connective tissue, cells, matrix, mineral salts, and collagen fibers

Bone Remodelling

Continuous process involving bone resorption and formation, influenced by factors like mechanical stress and hormones (e.g., calcitonin, parathyroid hormone)

Fracture Repair Process

Step 1: Hematoma formation; blood leaks, causing swelling and inflammation.
Step 2: Formation of fibrocartilaginous callus; bridging of broken ends using collagen and cartilage.
Step 3: Bony callus formation; fibrocartilage converts to spongy bone.
Step 4: Bone remodelling; replacement of spongy bone with compact bone results in a thicker, stronger repair site.

Factors Affecting Bone Healing

Delays can occur from: Tissue fragments, poor blood supply, misalignment, mobility of bone ends, and health factors (illness, malnutrition, aging).

Bone Mass Changes Over Lifespan

Bone deposition exceeds resorption from birth to adolescence; equal in young adults; females experience increased loss after age 30, while males do so after age 60.

Osteoporosis

Defined as an imbalance where bone resorption exceeds deposition, leading to decreased bone density.
Risk factors: Age, hormonal changes, inadequate calcium, and activity levels.

Progressive brittleness, thinner articular cartilage, reduced height due to intervertebral disc thinning, and increased rigidity in the thoracic cage.

Joint Types

Three types: Fibrous (little movement), Cartilaginous (small movement), Synovial (free movement)
Examples: Sutures (fibrous), Symphysis pubis (cartilaginous), Knee (synovial)

Synovial Joints

Types: Hinge joints (elbow), Ball and socket joints (shoulder)
Synovial membrane: Lines joint surfaces, produces synovial fluid for lubrication.

Synovial Fluid Functions

Reduces friction, absorbs shock, supplies nutrients to cartilage, contains immune cells.

Joint Movements

Types of movement include flexion, extension, hyperextension, rotation, and eversion/inversion, among others.

Arthritis Types

Osteoarthritis: Degenerative, non-inflammatory affecting weight-bearing joints.
Rheumatoid arthritis: Autoimmune, inflammatory leading to joint fusion.

Muscle Tissue Functions

Generates movement, maintains posture, regulates organ volumes, transports substances, produces heat, and protects structures.

Muscle Characteristics

Electrically excitable, contracts upon stimulation, stretches without damage, elastic, returning to original shape.

Muscle Types

Skeletal muscle: Moves skeleton, attached to bones; Cardiac muscle: Causes heart contractions; Smooth muscle: Changes organ diameters, organs' walls.

Neuromuscular Junction

Site where nerve impulses initiate muscle contractions through neurotransmitters like Acetylcholine (Ach).

Muscle Contraction Mechanism

Actin and myosin are contractile proteins that interact during muscle contraction.

Atrophy and Hypertrophy

Atrophy: Muscle wasting due to disuse or nerve issues; Hypertrophy: Increase in muscle size from repetitive activity.

Tendons vs. Ligaments

Tendons connect muscles to bones; ligaments connect bones to other bones.

Muscle Aging

Progressive loss of muscle mass and strength begins at age 30; regular exercise can combat effects.

Pelvic Floor Muscles

Supports pelvic organs, acts as sphincters for urethra, vagina, and rectum.

Intramuscular Injection Sites

Common sites: Gluteus Medius, Vastus Lateralis, Deltoid.

Lymphatic System Functions

Drains excess fluid, transports lipids from intestines, and plays a role in immune response.

Lymph Nodes Cells

B Cells and T Cells: Stimulate immune responses; Macrophages: Phagocytose foreign materials.

Lymphatic Nodules Locations

Peyer’s patches, appendix, tonsils are key concentrations of lymphatic tissues providing immune functions.

Spleen Functions

Removes damaged cells, stores platelets, produces blood cells in fetal life, fulfills immune roles.

Cancer and Infection Spread

Nodes can become overwhelmed with pathogens or cancer cells, leading to multiplication and infections.

Differences in Lymph Nodes

Cancerous nodes: Firm, enlarge, non-tender; Infected nodes: Soft, tender, moveable.

Defence Mechanisms

First line (innate/non-specific): Skin, tears, mucus, and cilia protect against microorganisms entering the body.### Friendly Bacteria and Immune Response
Friendly bacteria contribute to maintaining a balanced microbiome, which plays a role in preventing harmful infections.

Phagocytosis Overview

Key cells involved: Neutrophils, Monocytes, and Macrophages.
Phagocytosis functions to engulf and digest pathogens or cellular debris, serving as an essential mechanism of innate immunity.

Inflammation

Overall functions include:
- Destroying microbes and their by-products.
- Preventing spread of infection through formation of a fibrin wall.
- Clearing dead tissue and microbes from the affected area.
- Facilitating tissue repair.

Stages of Inflammation

Vasodilation and increased permeability of blood vessels to allow fluid and immune cells to enter.
Phagocyte migration to the damaged area, where they consume pathogens and debris.
Tissue repair processes begin following clearance of infection.

Fever in Inflammatory Response

Fever is a systemic response triggered by pyrogens, which reset the hypothalamic thermostat to a higher temperature.
Benefits of fever include slowing bacterial growth, enhancing immune responses, and facilitating recovery.

Implications of Fever Treatment

Benefits include:
- Slowed bacterial growth and improved immune efficiency.
- Shorter infection duration with enhanced tissue repair.
Complications can occur in vulnerable populations, like older adults, including dehydration, tachycardia, and potential seizures in children.

Immunity and Adaptive Immunity Cells

Immunity is the immune system's ability to defend against infectious agents.
Key cells include T lymphocytes (T cells) and B lymphocytes (B cells), both originating from bone marrow stem cells.

Categories of Adaptive Immunity

Antibody Mediated (Humoral):
- B cells proliferate and produce plasma cells to create antibodies.
Cell Mediated:
- T cells bind to and destroy infected cells displaying pathogens.

Immune Response: Primary vs. Secondary

Primary Response:
- Initial exposure to an antigen results in the production of antibodies.
Secondary Response:
- Faster and more robust immune response upon re-exposure to the same antigen, critical for effective long-term immunity.

Antibody Classes and Clinical Significance

IgG:
- Most abundant, triggers complement response, crosses the placenta, offers long-lasting immunity.
IgA:
- Found in secretions like saliva and breast milk, prevents tissue invasion by pathogens.
IgM:
- First antibody produced during infection, indicating recent exposure.
IgE:
- Involved in allergic reactions, binds to mast cells and basophils.

Major Histocompatibility Complex (MHC)

MHC proteins on cells identify them as "self" to prevent immune attacks on the body's own cells.
Unique to individuals and essential in organ transplantation to prevent rejection.

Types of Acquired Immunity

Natural Active:
- Exposure to pathogens initiates immune response, may provide lifelong immunity.
Natural Passive:
- Maternal antibodies (IgG and IgA) transferred to child through the placenta and breast milk.
Artificial Active:
- Vaccination prompts immune response without causing disease.
Artificial Passive:
- Injection of pre-formed antibodies for immediate but short-term immunity.

Vaccine Types

Live Attenuated:
- Contains weakened live pathogens, usually lifelong immunity (e.g., MMR).
Inactivated:
- Killed microbes, requires boosters (e.g., Influenza).
Subunit:
- Contains parts of the pathogen, needs multiple boosters (e.g., Hib).
Toxoids:
- Inactivated toxins to produce immunity, often requires boosters (e.g., DTaP).

Herd Immunity

Concept where a high percentage of the population is immunized, thereby providing indirect protection to non-immune individuals.

Immune System Undesirable Responses

Hypersensitivity reactions.
Autoimmune disorders.
Immune compromise conditions.
Reactions against transplanted tissues.
Chronic inflammation leading to tissue damage.

Newborns develop immunity through microbial exposure; excessive antibiotic use can hinder normal development.
Older adults experience reduced vaccine responses, increased auto-antibody production, and heightened infection susceptibility.

Selective Toxicity

Ability to target and kill pathogens without harming host cells by attacking structures unique to microbes.

Bactericidal vs. Bacteriostatic

Bactericidal:
- Kills bacteria directly.
Bacteriostatic:
- Inhibits bacterial growth, allowing the immune system to clear the infection.

Broad Spectrum vs. Narrow Spectrum Antibiotics

Broad Spectrum:
- Effective against a wide array of bacteria, useful in emergencies but may disrupt normal flora.
Narrow Spectrum:
- Targets specific pathogens, minimizing side effects and preserving normal flora.

Antimicrobial Mechanisms

Interference with cell wall synthesis.
Disruption of DNA replication.
Inhibition of protein synthesis.
Interruption of vital metabolic reactions.

Antibiotic Resistance

Occurs when microbes acquire the ability to withstand antimicrobial agents, such as MRSA and VRE.

Reducing Antibiotic Resistance Strategies

Avoid inappropriate prescription of antibiotics.
Complete full courses of treatment.
Use specific antibiotics rather than broad-spectrum when possible.

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Description

Test your knowledge of the digestive system by naming and labeling all the organs in the correct sequence from the mouth to the anus. Additionally, describe the nine regions and four quadrants of the abdominopelvic cavity, including the organs contained within each area.