MCAT Respiratory system and the skin Flashcards
Tiny sacs, with walls only a single cell thick, found at the end of the respiratory bronchiole tree.
Alveoli
___ are the site of gas exchange in the respiratory system
Alveoli
Very small air tubes in the respiratory system. The walls of the __ are made of smooth muscle to help regulate air flows
Bronchioles
Receptors in the central nervous system that monitor the pH of cerebrospinal fluid to help regulate ventilation rate.
Central chemoreceptors
A layer of connective tissue underneath the epidermis of the skin
Dermis
The __ contains blood vessels, lymphatic vessels, nerves, sensory receptors, and glands for the skin
Dermis
The primary muscle of inspiration.
Diaphragm
The __ is stimulated to contract at regular intervals by the respiratory center in the medulla oblongata (via the phrenic nerve). Although it is made of skeletal muscle ( and can therefore be voluntarily controlled), these stimulation’s occur autonomously
Diaphragm
____states that the amount of gas that will dissolve into liquid is dependent on the partial pressure of that gas as well as the solubility of that gas in the liquid
Henry’s Law
This is a layer of fat located under the dermis of the skin that helps to insulate the body and protects underlying muscles and other structures
Hypodermis
What are the three main functions of the larynx?
- Its rigidness ensures that the trachea is held open (provides an open airway)
- The epiglottis folds down to seal the trachea during swalling, directs food to the esophagus
- This is where the vocal cords are found (voice production
___are receptors in the carotid arteries and the aorta that monitor blood pH to help regulate ventilation rate
Peripheral chemoreceptors
The membranes that line the surface of the lungs (visceral pleura) and the inside wall of the chest cavity (parietal pleura)
Pleura
The pressure in the space between the lung surface and the inner wall of the chest cavity.
Pleural pressure
___ is negative with respect to atmospheric pressure; this keeps the lungs stuck to the chest cavity wall
Pleural pressure
A collection of fluid in the alveoli of the lungs, particularly dangerous if it impedes gas exchange. Common cause are increased pulmonary blood pressure or infection in the respiratory system
Pulmonary edema
A drop in blood pH due to HYPOVENTILATION and a resulting accumulation of CO2
Respiratory acidosis
A rise in pH due to HYPERVENTILATION and a resulting decrease in CO2
Respiratory alkalosis
An amphipathic molecule secreted by cells in the alveoli (type 2 alveolar cells) that reduces surface tension on the inside of the alveolar walls
Surfactant
This prevents the alveoli from collapsing upon exhale and sticking together, thus reducing the effort required for inspiration
Surfactant
___ cell secrete surfactant
Type 2 alveolar cells
The part of the respiratory system designed only to allow gas to enter and exit the system is called the __
conduction zone
Air pathway
Nose -> nasal cavity -> pharynx -> larynx -> trachea -> bronchi -> terminal bronchioles -> respiratory bronchioles -> alveolar ducts -> alveoli
Why is there no gas exchange in the conduction zone?
The smooth muscle of the walls of the terminal bronchioles is too thick to allow adequate diffusion of gases
From the nose all the way to the bronchioles, the epithelial cells are all___
tall columnar cells
The ___, ___, and the ___ are involved in gas exchange
alveoli, alveolar ducts, and the smallest bronchioles
___ reduces surface tension on the alveoli and helps them avoid collapsing
Surfactant
Each lung is surrounded by two membranes
- parietal pleura: lines inside of chest cavity
2. visceral pleura: lines the surface of the lungs
What 6 steps occur during inspiration?
- Diaphragm contracts and flattens (moves downward)
- The volume of chest cavity expands
- Pleural pressure decreases, becoming more negative
- Lungs expand outward
- Pressure in the alveoli become negative
- Air enters lungs and the alveoli
At the beginning of inspiration, the pleural pressure___
decreases, sucking the lungs open
___ is the amount of air that moves in and out of the lungs with normal light breathing and is equal to about 10 percent of the total volume of the lungs
Tidal volume (TV)
What are the principle chemical stimuli that affect ventilation rate?
Increased pCO2
decreased pH
decreased pO2
____ are found in the medullary respiratory control center and monitor pCO2 and pH of the cerebrospinal fluid
Central chemoreceptors
___ are located in the aorta and the carotid arteries and monitor the pCO2, pH, and pO2 of the blood
Peripheral chemoreceptors
During an allergic attack ___ release histamine which causes bronchoconstriction
Mast cell
___ does the opposite of histamine, it increases ventilation by causing airway smooth muscle to relax (bronchodilation)
Epinephrine
The epidermis is composed of ___cells
stratified squamous epithelial cells
Mitosis of epidermis cells occurs here and the newly divided cells move up towards the surface of the skin
Stratum basale
__helps make the skin waterproof
KEratin
___are sweat glands
Sudoriferous glands
____ are oil glands in the skin
Sebaceous glands
Sweat glands are responsive to the hormone__
aldosterone
People living in hot climates must sweat alot, how does aldosterone help?
They have high amounts of aldosterone which helps conserve sodium, their sweat doesn’t waste alot of salt
