Test #4 (Lymph, GI, Endocrine) Flashcards
Which bodily system is responsible for drainage of excess interstitial fluid, transportation of lipids (from the digestive system), and protection/immune responses
The Lymphatic System
Around how much excess fluid is drained into the lymphatic system per day?
~3 Litres
How do proteins that leak out of the blood capillaries return to circulation?
The Lymphatic System
What are the four steps of lymphatic flow?
capillaries -> lymphatic vessels -> trunks -> ducts
How is interstitial fluid driven into the lymphatic capillaries?
Cells forming the endothelium overlap to allow interstitial fluid in but not back out, and the pressure drives it into the capillaries.
Lymphatic capillaries merge into larger vessels called
lymphatic vessels
At regular intervals, lymph passes through:
lymph nodes
Bean shaped clusters of lymphocytes (B cells and T cells) surrounded by a dense CT capsule
lymph nodes
__________ lymph nodes are located along the lymphatic vessels of the body (often in groups,
superficial and deep).
~600
T/F: lymphatic vessels function in lymph filtration (lymph flows in, foreign substances are trapped and destroyed).
False, this is the function of lymph nodes.
Larger lymphatic vessels merge into ___________
trunks
Which lymphatic duct drains the left side of the head & neck, left side of the chest, and entire body below the ribs into the left subclavian vein?
The thoracic duct
Which lymphatic duct drains the right side of the head & neck and right side of the chest into the right subclavian vein?
The right lymphatic duct
What three actions maintain lymphatic flow?
1) skeletal muscle pump
2) diaphragmatic breathing/respiratory pump
3) smooth muscle contraction (in the vessel walls – minimal contribution)
Which lymphatic structure produces B cells and immature T cells (a.k.a. pre-T cells)?
Red Marrow
Which lymphatic organ, located in the mediastinum, produces mature T cells from pre-T cells.
It’s large at birth, significantly atrophied by maturity.
Thymus
Which lymphatic organ can be described as a large mass of lymphatic tissue between the stomach and the diaphragm that filters blood (similar to the process in a lymph node), removes ruptured, worn out, defective RBCs, and stores platelets and monocytes?
The Spleen
Which facet of the immune system provides rapid responses, doesn’t recognize specific invaders but reacts in the same way to all invaders (no memory component)
Non-Specific Defenses
The ______ Line of Defense consists of skin (tightly packed keratinized cells, shedding), mucous membranes (mucous traps microbes, cilia sweeps them out) and body fluids (sweat, tears, saliva, urine etc.)
The First Line
The ______ Line of Defense consists of antimicrobial proteins, natural killer (NK) cells, phagocytes, inflammation and fever.
The Second Line
Substances that are recognized as foreign and elicit an immune response.
Antigen
In specific responses, antigens/invaders are ________, _________, and _________
identified, killed and remembered
T/F: specific responses are slower than non-specific
True
What type of immune response is effective against fungi, parasites, viruses, some cancer cells, and foreign tissue?
Cell-Mediated Immune Responses (subset of specific response)
When an invader is recognized, T-cells differentiate into one of three types of cells:
1) helper T cells (trigger proliferation, perform other immune functions)
2) cytotoxic T cells: migrate to the site and destroy the invader
3) memory T cells: remain after the response, they don’t attack but with future
infections (same invader), they make for a faster and stronger response
What type of immune response is effective against antigens in body fluids and extracellular pathogens (e.g. bacteria)?
Antibody-Mediated Immune Responses (subset of specific response)
When an invader is recognized, B-cells differentiate into one of two types of cells:
• plasma cells which secrete antibodies
• memory B cells: remain after the response, they don’t attack but with future
infections (same invader), they make for a faster and stronger response
a.k.a. immunoglobulins, proteins produced by plasma cells in response to an antigen which neutralize, inhibit, or destroy the antigen
antibodies
Most common type of antibody, found in blood/lymph/intestines, protect against bacteria, viruses. They cross the placenta to confer immunity to the newborn
IgG
Type of antibody found in sweat/tears/saliva/mucous/breast milk/GI. Levels decrease during stress.
IgA
Type of antibody found in blood/lymph. Part of blood transfusion reactions.
IgM
Type of antibody involved in allergic/hypersensitivity reactions, protects against parasitic worms. Found in blood.
IgE
Type of antibody that helps activate B cells. Found in blood.
IgD
The breaking down of food into molecules small enough to be absorbed
Digestion
The passage of molecules through the plasma membranes of the cells lining the stomach and intestines into the blood and lymph.
Absorbtion
a.k.a. alimentary canal, the continuous tube from the mouth to the anus
the gastrointestinal tract
accessory \_\_\_\_\_\_\_\_\_organs • teeth • tongue • salivary glands • liver • gallbladder • pancreas
digestive
How cells in the walls of the GI Tract and accessory organs release water, acid, buffers, and enzymes into the lumen of the tract.
secretion
muscles in the organ wall rhythmically contract and relax to mix the food and secretions together and to move the mixture through the system
Mixing and Propulsion
__________ Digestion
• the tongue mixes food
• the teeth grind and cut food
• the stomach and small intestine churn/mix food
Mechanical
__________ Digestion
• enzymes help break larger nutrients into smaller ones (which can then be absorbed)
• enzymes are secreted by the salivary glands, tongue, stomach, pancreas, small
intestine
Chemical
nutrition is taken in through the membranes of cells lining the stomach and small intestines, enters the blood or lymphatic system and is circulated throughout the body.
Absorbtion
a. k.a. defecation
feces: wastes, undigested substances, unabsorbed substances, bacteria, cells sloughed off from the GI tract lining
Elimination
Structure involved in digestion, skeletal muscle covered in mucous membrane
The tongue
salivary glands (major ones)
1) _________: inferior and anterior to the ear, between the skin and the masseter
2) ________ : floor of the mouth
3) ________ : beneath the tongue
1) Parotid
2) Submandibular
3) Sublingual
a.k.a. throat, skeletal muscle lined with mucous membrane. muscle contractions move the bolus from the mouth into the ____ then into the esophagus
Pharynx
a collapsible muscular tube sitting posterior to the trachea
esophagus
the esophagus runs from the lowest segment of the 1) through the 2) (the esophageal
hiatus) to the superior aspect of the 3)
1) pharynx
2) diaphragm
3) stomach
wave-like contractions of the smooth muscle lining the walls of the GI tract that move the bolus along the tract (from the esophagus to the anus)
Peristalsis
passage of food from the pharynx into the esophagus is controlled by the_______________
upper esophageal sphincter
passage of food from the esophagus into the stomach is controlled by the _______________
lower esophageal sphincter
Name the layers of the GI tract from deep to superficial.
1) mucosa
2) submucosa
3) muscularis
4) serosa
What consists of
a) epithelial cells
b) exocrine cells (secrete mucous, liquid)
c) enteroendocrine cells (secrete hormone) ?
The epithelium of the mucosa layer of the GI tract
What consists of
a) CT (areolar)
b) blood and lymphatic vessels (for absorption)
c) mucosa-associated lymphatic tissue (MALT) (for immune function/protection)?
The lamina propria of the mucosa layer of the GI tract
a smooth muscle layer that creates folds in the mucosa
muscularis mucosa
a CT layer that binds the mucosa to the muscularis layer. contains many blood and lymphatic vessels (for nutrient transport), and neurons of the enteric nervous system for GI control
submucosa
The muscularis is comprised of 1) in the mouth, pharynx, upper 2/3rds of the esophagus, external anal sphincter, and 2) everywhere else
1) skeletal muscle
2) smooth muscle
This layer of the GI tract has 2 sublayers generally in 2 layers: circular fibres and longitudinal fibres
The muscularis
Contractions (frequency and strength) of the muscularis are controlled by the __________ nervous system
enteric
outermost layer of the organs in the abdominal cavity, a.k.a. visceral peritoneum
Serosa
The Peritoneum is comprised of 2 layers:
1) ____________ peritoneum (a.k.a. the serosa)
2) ____________ peritoneum
between the 2 layers is the 3) _____________
1) visceral
2) parietal
3) peritoneal cavity
Some organs (kidneys, ascending and descending colons, duodenum, pancreas) are covered by the peritoneum on their anterior side only – they are called\_\_\_\_\_\_\_\_\_\_\_\_\_
retroperitoneal
The Stomach is a ________-shaped enlargement of the GI tract
J-shaped
The Stomach sits immediately below the __________
diaphragm
Food enters the stomach through the ________
Lower esophageal sphincter
the soupy mix of food in the stomach is called ________
chyme
T/F: the majority of absorption happens in the stomach
False: little – no absorption happens in the stomach (water, ions, some fats, medications, alcohol)
Once food particles are small enough, they pass through the _________________ into the small intestine
pyloric sphincter
the wall of the stomach has the same 4 layered arrangement with these two additions:
1) specialized cells
2) additional layer of smooth muscle
the mucosal layer of the stomach has specialized cells that secrete:
a) __________ (mucous neck cells)
b) intrinsic factor and HCl- (__________ cells)
c) pepsinogen and gastric lipase (_______ cells)
d) _________ (a hormone secreted by G cells))
• stimulates gastric juice production
• strengthens LES contraction
• increases stomach peristalsis
• relaxes the pyloric sphincter
e) secretions from mucous, parietal and chief cells (G cells not included) are collectively called _________
a) mucous
b) parietal
c) chief
d) gastrin
e) gastric juice
the muscularis of the stomach has an additional (oblique) layer of smooth muscle to facilitate ________
mixing
The Small Intestine is ~ a) __ m long and b) __cm diameter
a) 3m
b) 2.5 cm
the mucosal layer of the small intestine has villi – finger-like projections that increase surface area. each villus is covered in ___________
epithelium
Name the three regions of the small intestine
1) duodenum
2) jejunum
3) ileum
cells of the epithelium:
1) __________ cells (digestion/absorption)
2) __________ cells (mucous)
3) _________ cells (kill bacteria)
4) _________ cells (secrete hormones)
1) absorptive cells (digestion/absorption)
2) goblet cells (mucous)
3) Paneth cells (kill bacteria)
4) enteroendocrine cells (secrete hormones)
each villus of the small intestine has an ______, a _______ and a ________
1) arteriole
2) venule
3) lacteal
absorbed nutrients in the small intestine pass into either:
1) ______________ (carbohydrates, proteins, water, electrolytes, water-soluble vitamins) and go to the liver or 2) ______________ (lipids) via a lacteal.
remaining food passes through the ileocecal valve/sphincter into 3)
1) the blood stream
2) the lymphatics
3) the large intestine
The Pancreas sits ___________ to the stomach
Posterior
T/F: endocrine function of the pancreas is to secrete pancreatic juice (water, salts, sodium bicarbonate, enzymes) into the duodenal lumen
False: This is an exocrine function (happens through ducts)
Juices are secreted from the pancreas into the proximal duodenum via 2 main ducts:
1) a ________ duct formed by the pancreatic duct joining the common bile duct from the liver/gallbladder
2) ________ duct
1) common
2) accessory
The liver sits ________ to the diaphragm in the right __________region of the abdominal cavity
1) inferior
2) superior
T/F: The liver has 2 lobes: larger left and smaller right
False: larger right and smaller left
The liver receives blood flow from 2 sources:
1) ___________ – oxygenated blood
2) __________ – deoxygenated blood containing absorbed nutrients, medications,
microbes and toxins
1) hepatic artery
2) hepatic portal vein
blood in the liver flows past __________ (liver cells), which absorb oxygen, nutrients and toxins, and release nutrients (needed by other cells)
Hepatocytes
hepatocytes also manufacture and secrete ______
Bile
T/F: when the body has low blood sugar, hepatocytes remove glucose from the blood and store it (as
glycogen and fats)
False:
low blood sugar – hepatocytes break down glycogen and release glucose into the
blood
high blood sugar – hepatocytes remove glucose from the blood and store it (as
glycogen and fats)
A pear-shaped organ sitting in the posterior surface of the liver that stores and concentrates bile
Gallbladder
A yellow/brown/olive liquid made by hepatocytes that collects into larger and larger vessels
and functions in emulsification (breakdown) of fats
Bile
food enters the large intestine from the small intestine (ileum) through the __________ valve/sphincter
ileocecal
T/F: The large intestine functions in completion of absorption, vitamin C production, formation and elimination of feces
False: vitamin K production
Small pouch attached to the ileocecal valve
Cecum
Attached to the cecum is the _________
Appendix
contents move from the cecum into the ________
colon
The Colon is divided into 4 portions:
1) _________ (to the hepatic flexure)
2) ________ (to the splenic flexure)
3) ________ (to the left iliac crest)
4) ________ (to the rectum at ~ S3)
1) ascending (to the hepatic flexure)
2) transverse (to the splenic flexure)
3) descending (to the left iliac crest)
4) sigmoid (to the rectum at ~ S3)
as food accumulates in the ascending colon, small segmented pouched called ________ fill up/distend which stimulates smooth muscle contraction
Haustra
T/F: Peristalsis occurs very quickly in the colon
False: regular peristalsis occurs but more slowly
Terminal portion of the large intestine
Anal canal
elimination control: ___________ (involuntary control) and __________ (voluntary control) anal
sphincters
internal and external
Distension of the rectum ultimately gives the urge to go and relaxes the internal anal sphincter. This is called the:
The defecation reflex
Divisions of the GI Tract
upper GI: _____, _______, _______, ______, _____
lower GI: ________________and _______
upper GI: mouth, pharynx, esophagus, stomach, duodenum
lower GI: most of the intestines and the anus
In this phase of digestion, the thought, smell, sight, initial taste of food activates the NS. salivary and gastric glands are stimulated to prepare the mouth and stomach for digestion.
Cephalic Phase of digestion
once food reaches the stomach:
_________ receptors are stimulated by the change in the stomach shape
_________ receptors are stimulated by the change in stomach pH
stretch receptors
chemo receptors
Phase in which small amounts of chyme pass through the pyloric sphincter into the duodenum and food leaving the stomach decreases the volume of the stomach and removes some of the stimulus from stretch receptors.
Gastric phase
chyme in the duodenum causes enteroendocrine cells to release hormones:
1) __________
2) _________
1) cholecystokinin (CCK)
2) secretin
In this phase, hormones:
• stimulate the gallbladder to eject bile into the duodenum
(CCK)
• secretin decrease gastric juice production (CCK/secretin)
• slow food coming through the pyloric valve (CCK/secretin)
• increase pancreatic juice secretion (CCK/secretin)
Intestinal Phase
