Lab Exam 2

Which organ is the primary site of raising an immune response?

Lymph nodes

What is the composition of the lymphatic system?

Lymph nodes, lymphatic vessels, spleen, thymus, tonsils, adenoids, bone marrow, and lymph fluid

Which cells recognize antigens and initiate the immune response?

Dendritic cells

What is the function of B cells in the immune response?

They are responsible for humoral immunity by producing pathogen-specific antibodies (immunoglobulins)

What type of immunity do B cells provide?

Humoral immunity

What do antibodies do?

Identify and neutralize foreign invaders like bacteria, viruses, and toxins

Antigen

Any substance - commonly proteins, polysaccharides, or lipids - that the immune system recognizes as foreign, triggering a targeted immune response such as antibody production

Antibody

Y-shaped proteins produced by B-cell white blood cells to identify and neutralize foreign invaders like bacteria, viruses, and toxins (antigens)

Humoral immunity

A branch of the adaptive immune system that defends against extracellular pathogens (bacteria, toxins, viruses) in body fluids. Mediated by B lymphocytes and antibodies, it involves B cells identifying pathogens, maturing into plasma cells, and secreting antibodies to neutralize or destroy them

Antigen-presenting cell (APC)

A specialized immune cell that engulfs pathogens, breaks them down into antigens, and displays these fragments on its surface using Major Histocompatibility Complex (MHC) proteins. By presenting these antigens to T cells, APCs initiate the adaptive immune response, acting as a crucial bridge between innate and adaptive immunity

Plasma cell

Specialized terminally differentiated B-lymphocyte white blood cells that act as “antibody factories” in the adaptive immune system, secreting large volumes of immunoglobulins to combat pathogens. They originate from B cells, typically reside in the bone marrow or lymphoid tissues, and are essential for long-term humoral immunity

Lymph node

Immune system, Filter and clean lymph fluid, house and activate white blood cells (lymphocytes), and launch targeted immune responses against infections

Spleen

Destroys pathogens, removes old red blood cells, and produces lymphocytes, has white pulp (immune cell production) and red pulp (filtration), stored blood cells and platelets for rapid immune response

What is the major site of nutrient absorption in the GI tract?

The small intestines

What is the mesentery attached to the inferior margin of the stomach called?

The greater omentum

What is the portion of the stomach closest to the duodenum called?

Pylorus or pyloric part

Which accessory organ produces digestive enzymes that act in the small intestine?

The pancreas - enzymes work specifically in the duodenum (amylase, lipase, and proteases)

Peristaltic waves occur in all GI organs EXCEPT which one?

The pharynx

What is the serous membrane that lines the thoracic walls called?

The parietal pleura

Which enzyme digests carbohydrates?

Primarily Amylase, also maltase, sucrase, and lactase

In fat digestion: what is the substrate? What is the enzyme?

Substrate - dietary fat (triglycerides, lipids), enzymes - lipase

Which protein-digesting enzyme works optimally at pH 1.5–2.0?

Pepsin

When proteins are digested, what molecules can be absorbed?

Amino acids, dipeptides, tripeptides

Peristalsis

A series of involuntary, wave-like muscle contractions that move food, liquids, and waste through the digestive tract

Mesentery

A fold of peritoneum which attaches the stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen, fan-shaped

Pylorus

The opening from the stomach into the duodenum (small intestine)

Greater Omentum

A large, apron-like fold of visceral peritoneum, often called the “policeman of the abdomen”, hangs from the stomach’s greater curvature, covering intestines

Parietal layer of the serous membrane

lines the walls of the body cavity

Visceral layer of the serous membrane

covers the organs inside the body cavity

Substrate

The specific molecule upon which an enzyme acts acting as the reactant that binds to the enzyme’s active site to form a product

Enzyme

A biological catalyst, usually a protein, that speeds up a specific chemical reactions within living cells without being consumed in the process

Oral cavity (mouth)

Function: initiates digestion through mastication, enzymatic chemical processing (saliva), facilitates swallowing, enables speech articulation, supports breathing, provides taste sensation, immunological defense against pathogens

Location: Lower part of the head, below nasal cavity

Esophagus

Function: transport food and liquid from the pharynx to the stomach using muscle contractions (peristalsis)

Location: in the chest, running behind the windpipe (trachea) and in front of the spine, extending from the throat through the diaphragm to the stomach

Stomach

Function: mechanical digestion (churns, mixes, and breaks down food through muscular contractions), chemical digestion (secretes HCl and enzymes, like pepsin, to break down food), formation of chyme, some absorption (water, caffeine)

Location: left upper quadrant, tucked under ribs and diaphragm between the esophagus and small intestines

Small intestine

Function: digestion (uses chyme, bile, and enzymes from the pancreas to break down food into liquid nutrients), absorption, immune defenses

Location: abdominal cavity, framed by large intestines, extending from stomach to the large bowel

Large Intestine (colon)

Function: absorb water, salts, and vitamins from undigested food, solidify waste into stool, propel waster into the rectum for elimination

Location: abdominal cavity, framing the small intestine in an inverted “U” shape from the right pelvic region to the anus

Rectum/Anus

Function: store fecal matter until defecation, manage the elimination process, and absorb remaining electrolytes

Location: pelvic cavity between the sigmoid colon and the anal canal, directly in front of the sacrum

Liver

Function: detoxifying blood, producing bile, metabolizing nutrients, storing energy

Location: upper right quadrant, tucked beneath the diaphragm and behind the rib cage

Gallbladder

Function: store and concentrate bile, release it into the small intestine (duodenum)

Location: upper right abdomen, tucked directly under the liver

Pancreas

Function: endocrine and exocrine gland, enzyme production (amylase, lipase, proteases), and hormone production (insulin, glucagon)

Location: upper abdomen, behind stomach, extending horizontally from the curve of the duodenum to the spleen

Salivary Glands

Function: moisten food for swallowing, initiate starch digestion (via amylase), protect oral mucosa, aid in taste, and maintain hygiene

Location: in and around the mouth and throat, near the ears, and under the jaw

Appendix

Function: safe house for beneficial gut bacteria and contains immune cells to support gut health

Location: lower right abdomen, attached to the cecum where the small and large intestines meet

What are the functions of the nasal cavity?

Filters, warms, and humidifies inhaled air before it reaches the lungs, acts as a primary immune defense by trapping particles in mucus, and provides a sense of smell

What does the larynx do?

Directs food into the esophagus and away from choking, contains vocal cords which create sound for speech, breathing regulation, assists in coughing to clear the airway of mucus of foreign debris

What is the flap of elastic cartilage that forms a lid over the larynx?

The epiglottis

What is the function of the epiglottis?

Closes over the trachea during swallowing, directing food and liquids into the esophagus and preventing aspiration into the lungs

Which lobes of the lungs are found at the apex?

Superior lobes

How many lobes does the right lung have? The left?

Right- 3, Left - 2

What feature is unique to the left lung? (Related to the heart)

The left lung only has two lobes to make space for the heart and the cardiac notch which is a distinct, concave indentation on the anterior border of the superior lobe of the left lung to accommodate the left-sided position of the heart

Apex of the lung

Rounded superior tip of each lung that projects into the root of the neck, situated 2.5-4 cm above the clavicle’s sternal end and the first rib

Base of the lung

The broad, concave inferior surface that rests directly on the diaphragm

Hilum

A wedge-shaped depression or notch located on the medial (inner) surface of each lung, acting as the entry and exit point for essential structures

Parietal pleura

The outer layer of the serous membrane that lines the inner surface of the thoracic cavity

Visceral pleura

A thin, delicate serous membrane that directly covers the surface of the lungs, extending into the fissures between the lobes

Epiglottis

A flap of cartilage at the root of the tongue, which is depressed during swallowing to cover the opening of the windpipe

Larynx

The hollow muscular organ forming an air passage to the lungs and holding the vocal cords in human and other mammals; the voice box

Carina

A cartilaginous, keel-like ridge located at the base of the trachea (windpipe) where it splits into the left and right main bronchi

Right primary bronchus

The wider, shorter, and more vertical airway branching from the trachea at the carina, entering the right lung’s root

Left primary bronchus

The airway passage branching from the trachea to the left lung, narrower, longer, and more horizontal than the right primary bronchus