3 ORGANS Flashcards
The superior opening of the larynx
epiglottis
Give the correct pathway of respiratory system
Pathway: Nose → Pharynx → Larynx → Trachea → Bronchi →Lungs
It only occurs ONLY in alveoli (tiny air sacs in the lungs
Gas exchange
Carry, purify, humidify, and warm incoming air
Conducting Passageways
Pathway of Upper Respiratory Tract (URT)
what common infection can be there.
Nose → Larynx
• Common infections: URTIs
The only externally visible part of the respiratory system
Nose
Empty area in the interior part of the nose
Nadal Cavity
What is the length of the pharynx?
About 13 cm (5 inches).
It is a common passageway for food and air and houses lymphatic tissues like tonsils.
pharynx
What are the three regions of the pharynx, and what are their roles?
Nasopharynx: Region where air enters; connects with the nose and pharyngotympanic tubes.
Oropharynx: Where air and food meet.
Laryngopharynx: Leads to the larynx and continues with the esophagus.
What structure in the pharynx acts as a crossroad for food and air?
The epiglottis.
neuropharyngeal swab is used for?
It collects samples from the back of the nose area. Example: COVID-19 testing.
What is the primary function of the larynx?
It routes air and food into proper channels and plays a role in speech.
How many cartilages make up the larynx, and what are they?
Eight hyaline cartilages and one elastic cartilage (epiglottis).
What is the largest cartilage in the larynx, and what is it also called?
The largest hyaline cartilage is the Adam’s apple.
Why is the epiglottis called the ‘Guardian of the Airway’?
It protects the superior opening of the larynx, allowing air passage during breathing and preventing food from entering the airway during swallowing.
What triggers the cough reflex, and when does it not work?
It is triggered when anything other than air enters the larynx. It does not work when a person is unconscious.
What forms the vocal folds, and what is their function?
Vocal folds are folds in the mucous membrane of the larynx that vibrate with expelled air to produce speech.
What determines the quality of a person’s voice?
The genetic and structural properties of the vocal folds.
What is the length and location of the trachea?
About 10 to 12 cm (4 inches) long, located in the midchest area (fifth thoracic vertebra).
Why is tracheal obstruction life-threatening?
It is the only pathway for air to enter the lungs.
What reinforces the tracheal walls?
C-shaped rings of hyaline cartilage.
What lines the trachea, and what is its function?
Lined with ciliated mucosa that propels mucus away from the lungs to the throat.
What type of epithelium is found in the trachea?
Pseudostratified ciliated columnar epithelium.
How does smoking affect the trachea?
Smoking destroys the cilia, causing mucus to accumulate in the lungs, which leads to coughing as compensation.
What forms the main bronchi?
The division of the trachea.
Why is the right main bronchus more prone to obstruction?
It is wider, shorter, and straighter than the left bronchus.
Where are the lungs located?
They occupy the entire thoracic cavity except for the mediastinum.
How many lobes do the left and right lungs have, and why?
Left lung: 2 lobes; Right lung: 3 lobes. The left lung is smaller to accommodate the heart.
A branching system of passageways within the lungs that ends in bronchioles.
bronchial tree
What are the components of the respiratory zone?
Respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
Where does gas exchange occur?
In the alveoli
What type of epithelium forms the alveoli walls?
Simple squamous epithelial tissue.
They cover the external walls of the alveoli and facilitate gas exchange.
pulmonary capillaries
A barrier formed by alveoli and pulmonary capillaries for gas exchange via simple diffusion.
respiratory membrane
What happens during pulmonary edema?
Water enters the alveoli due to low albumin, leading to impaired gas exchange.
They are the final line of defense and the site for gas exchange in the respiratory system.
alveoli
alveolar macrophages is also called as?
and what do they do?
Also called ‘dust cells,’ they pick up bacteria and debris in the alveoli.
What is surfactant, and why is it important?
A lipid molecule that lowers the surface tension in alveoli, preventing collapse between breaths.
Converts food into raw material that builds and fuels our body’s cells.
Digestive system
What are the two main groups of organs in the digestive system?
- Organs forming the Alimentary Canal - Performs digestive functions.
- Accessory Digestive Organs - Assist digestion in various ways.
A continuous, coiled, hollow, muscular tube that winds through the ventral cavity from the mouth to the anus.
Alimentary Canal
What organs are included in the Alimentary Canal?
Mouth, Pharynx, Esophagus, Stomach, Small Intestine, Large Intestine.
Why is food in the Alimentary Canal not considered ‘inside’ the body?
It only has contact with the cell lining the tract and the canal is open to the external environment at both ends.
What is the role of the mouth in digestion?
Food enters the digestive tract through the mouth, where breakdown begins with mastication, saliva, and enzymes.
What is mastication?
The process of chewing food, primarily performed by the masseter muscle.
What is the function of the pharynx?
Propels food into the esophagus through a mechanism known as peristalsis.
A passageway that conducts food from the pharynx to the stomach by peristalsis.
esophagus
What are the layers of the Alimentary Canal organs?
- Mucosa - innermost layer.
- Submucosa - soft connective tissue.
- Muscularis Externa - smooth muscles.
- Serosa - outermost layer.
Acts as a temporary storage tank for food and is the site for both physical and chemical food breakdown.
stomach
What are the regions of the stomach?
Cardial/Cardia, Fundus, Body, Pyloric Antrum, Pylorus.
It controls the entry of food into the stomach from the esophagus.
cardioesophageal sphincter
What happens if the cardioesophageal sphincter fails?
Backflow can cause acid reflux (heartburn).
It connects the pylorus and the small intestine, regulating the passage of chyme.
pyloric sphincter
What is the role of the muscularis externa in the stomach?
Allows for the churning, mixing, and pummeling action of food breakdown.
What initiates the chemical breakdown of proteins in the stomach?
Digestive enzymes activated by hydrochloric acid (HCl).
Produce hydrochloric acid (HCl) which activates pepsinogen to pepsin.
parietal cells in the stomach
An active enzyme that digests proteins in the stomach.
pepsin
What are enteroendocrine cells?
Cells that produce local hormones, such as gastrin, regulating digestive activities.
What is chyme?
The thick heavy cream full of nutrients that results from food processing in the stomach.
What stimulates the release of histamine in the stomach?
The moment food enters the stomach.
What is the major digestive organ of the body?
The small intestine.
What is the length of the small intestine?
2-4 meters.
The junction where the ileum joins the large intestine.
ileocecal valve
What aids in the chemical breakdown of food in the duodenum?
Bile and pancreatic enzymes.
Where is bile produced?
By the liver.
Where does nearly all nutrient absorption occur?
In the small intestine.
What are the three subdivisions of the small intestine?
Duodenum, jejunum, and ileum.
What is the duodenum?
The first part of the small intestine, also known as ‘Twelve Finger Widths.’
The second part of the small intestine, also known as ‘Empty.’
jejunum
The last part of the small intestine, also known as ‘Twisted Intestine.’
ileum
What structures increase the absorptive surface area of the small intestine?
Villi, microvilli, and circular folds (plicae circulares).
Finger-like projections that contain a rich capillary bed and lymphatic capillary (lacteals).
villi
Tiny projections of the plasma membrane of the mucosa cells that have brush border enzymes.
microvilli
Deep folds of both mucosa and submucosa layers that increase surface area.
circular folds (plicae circulares)
What happens to the number of villi, microvilli, and circular folds toward the end of the small intestine?
They decrease in number.
What increases in number toward the end of the small intestine?
Peyer’s patches (lymphatic tissue).
What is the major function of the large intestine?
To dry out indigestible food by absorbing water and to eliminate residues as feces.
What is the composition of the large intestine?
Cecum, appendix, colon, rectum, anal canal, and anus.
The first part of the large intestine.
cecum
A worm-like lymphatic tissue hanging from the cecum
Appendix
Contains the ascending and descending colon, and becomes the sigmoid colon in the pelvis.
colon
What is the rectum?
Part of the large intestine that lies in the pelvis.
What are the two types of anal sphincters?
External anal sphincter (voluntary) and internal anal sphincter (involuntary).
A condition where water is secreted excessively.
diarrhea
What is the role of teeth in digestion?
They help in mastication to physically break down food.
What do salivary glands produce?
Saliva that helps moisten and bind food into a bolus.
A small ball of food for easier consumption.
bolus
What enzyme begins starch digestion?
Salivary amylase.
What does the pancreas produce?
Enzymes that break down all categories of digestible food.
What is the liver’s role in digestion?
It creates and produces bile.
A yellow-to-green watery solution that contains bile salts and phospholipids.
Bile
What is the function of bile salts?
To emulsify fats by breaking large fat globules into smaller ones.
A small, thin-walled green sac that stores bile.
gallbladder
A hardened bile
gallstone
An active voluntary process of placing food into the mouth.
ingestion
What is propulsion in digestion?
The movement of food from one organ to the next, such as swallowing.
What is peristalsis?
Involuntary waves of contraction and relaxation that squeeze food along the tract.
The physical fragmentation of food into smaller particles.
mechanical breakdown
The chemical breakdown of large food molecules into their building blocks.
digestion
The transport of digestive end products from the GI tract to the blood or lymph.
Absorption
The elimination of indigestible residues and gut bacteria from the GI tract.
defecation
What are the components of carbohydrates during breakdown?
Disaccharides, dextrinase, and glucoamylase.
What enzyme activates pepsin?
Hydrochloric acid (HCl).
What enzyme breaks down lipids?
Lipase.
What enzyme initiates protein digestion in the stomach, and under what condition does it become active?
Pepsin, secreted by stomach glands, becomes active in the presence of hydrochloric acid (HCl).
What enzymes are responsible for breaking down large polypeptides in the small intestine?
Pancreatic enzymes, including trypsin, chymotrypsin, and carboxypeptidase.
Which enzymes complete the digestion of proteins into amino acids in the small intestine?
Brush border enzymes, such as aminopeptidase, carboxypeptidase, and dipeptidase.
How are amino acids absorbed in the small intestine and transported to the liver?
Amino acids enter the capillary blood in the villi and are transported to the liver via the hepatic portal vein.
What process emulsifies fats in the small intestine, and what is the source?
Fats are emulsified by bile salts, which are produced by the liver.
Which enzyme breaks down emulsified fats in the small intestine?
Pancreatic lipase.
What are the end products of fat digestion, and how are they absorbed?
The end products are monoglycerides and fatty acids. They are absorbed into the lacteals of the villi and enter systemic circulation via the lymphatic system, or they enter capillary blood and are transported to the liver via the hepatic portal vein.
What are the gonads?
Primary sex organs: testes; ovaries.
What is the purpose of the male and female reproductive system?
To produce an offspring.
What is the reproductive role of a man?
To produce male gametes (sperm) and deliver them to the woman’s reproductive tract through intercourse.
What is the reproductive role of a woman?
To produce female gametes (ovum).
The sperm-producing and hormone-producing functions are carried out by different cell populations.
Testes
The actual ‘sperm-forming’ factories in the testes.
seminiferous tubules
Cells that help care for sperm cells; known as ‘nurse cells.’
Sertoli cells
What do interstitial cells produce?
Androgens, including testosterone.
A highly convoluted tube that hugs the posterior side of the testis, providing a temporary storage site for immature sperm.
epididymis
How long do sperm travel through the epididymis?
For approximately 20 days, during which they complete maturation and begin to swim.
What is the ductus deferens?
Also known as the vas deferens, it propels live sperm from storage sites into the urethra.
What happens during ejaculation?
Smooth muscle walls create peristaltic waves that squeeze the sperm forward.
What is a vasectomy?
The cutting of the vas deferens, preventing sperm from leaving the body.
What does urethra carries?
both urine and semen to the body exterior.
What are the three regions of the urethra?
Prostatic urethra, membranous urethra, and spongy (penile) urethra.
Structures that aid in the delivery of sperm and produce the bulk of semen.
accessory glands
What do seminal vesicles produce?
60% of the seminal fluid, which is rich in sugar, vitamin C, and prostaglandins.
Produces a milky fluid that activates sperm and joins with seminal fluid during ejaculation.
prostate
What do bulbourethral glands produce?
A thick, clear mucus that cleanses the urethra and acts as a lubricant during sexual intercourse.
A milky white, sticky mixture of sperm and accessory gland secretions.
semen
What is the normal value of semen per ejaculate?
2 to 5 mL, containing about 50 to 150 million sperm per milliliter.
What is considered infertile in terms of sperm count?
A sperm count of less than 20 million per mL.
scrotum must have a temperature of?
why is the temperature important?
3°C lower than body temperature, necessary for healthy sperm production.
What is the penis’s function?
To deliver sperm into the female reproductive tract.
What is the glans penis?
The enlarged tip of the penis.
What happens during an erection?
Erectile tissue fills with blood, allowing the penis to deliver semen into the female reproductive tract.
A barrier formed by alveoli and pulmonary capillaries for gas exchange via ___?
simple diffusion
Epididymis is a storage site for ______?
immature sperm
Gallbladder stores _______?
Bile
Esophagus is passageway that conducts food from the pharynx to the stomach by _______.
peristalsis
