A&P 4 Flashcards
4 main processes of Respiration
- Pulmonary Ventilation
- External Respiration
- Transport
- Internal Respiration
Pulmonary Ventilation
(breathing) moving air into and out of our lungs
External Respiration
happens at the pulmonary capillaries; gas exchange between the lungs and the blood
Transport
transport of O2 and CO2 between the lungs and tissues
Internal Respiration
gas exchange between the systemic blood vessels and tissues; happens in systemic capillaries
Movement of Air
Conducting Zone:
Nose - nasal cavity - pharynx - larynx - trachea - primary (main) bronchi - secondary (lobar) bronchi - tertiary bronchi - 23 branches - - - bronchioles - terminal bronchioles - respiratory zone
Respiratory zone:
Respiratory bronchioles - alveolar ducts - alveolar sacs - individual alveoli
Function of Nose
to warm, moisten, and filter air
What are the cells that line the nose
Ciliated pseudostratified columnar epithelial tissue
Nasal Conchae
helps increase the surface area available to warm and filter the air
3 important points of the paranasal sinuses
- Sinuses are hollow places in our skull
- sinuses reduce the weight of the skull and serve as a chamber to affect the quality of voice
- play a role in filtering air
epiglottis
elastic cartilage which prevents food and liquid from going into the lungs
Larynx (voice box)
houses the vocal cords
composed of thyroid cartilage, cricoid cartilage, epiglottis and elastic tissue
Vocal Cords
2 pairs of folds of muscle and connective tissue
Upper pair: false vocal cords: protection and regulation
Lower pair: true vocal cords: produce voice and sound
What is the tracheal wall supported by
the tracheal wall is supported by 20 incomplete cartilaginous rings which keeps the trachea open at all times
What makes up the bulk of our lungs
Alveoli; the more alveoli the more gas exchange that occurs
Type 2 alveolar cells
produces surfactant which reduces surface tension and prevents alveoli collapsing when we exhale
Which lung is larger
The right lung is larger (3 lobes)
Left lung (2 lobes)
What covers the lung and what covers the thoracic cavity and what is layer between them
Visceral pleura - lung
Parietal pleura - thoracic cavity
A serous fluid lubricates pleural cavity between them
What is the movement of pressure in our body
High to low pressure
Atmospheric Pressure
the force that moves air into the lungs; 760 mm Hg
When pressure on the inside of the lungs decreases, does higher or lower pressure air flow in from the outside
higher pressure
how is air pressure inside the lungs decreased
it decreases by increasing the size of the thoracic cavity ; surface tension between the 2 layers of pleura the lungs follow with the chest wall and expand
What are the muscles involved with breathing
the external intercostal muscles and the diaphragm
as the lungs expand what keeps the alveoli from sticking together and collapsing
surfactant
Sequence of events in Inspiration
- Inspiratory muscles contract (diaphragm descends and rib cage rises)
- thoracic cavity volume increases
- The lungs are stretched; intrapulmonary volume increases
- Intrapulmonary pressure drops (to -1mm Hg)
- air flows into the lungs down its pressure gradient until intrapulmonary pressure is 0
Forced inspiration and muscles involved
Contraction of more muscles in the thoracic cavity;
Pectoralis Minor and Sternocleidomastoid
Sequence of events in Expiration
- Inspiratory muscles relax (diaphragm rises and rib cage descends)
- Thoracic cavity volume decreases
- elastic lungs recoil passively; intrapulmonary volume decreases
- Intrapulmonary pressure rises (to +1 mmHg)
- air flows out of the lungs down its pressure gradient until intrapulmonary pressure is 0
Forced Expiration and the muscles involved
is aided by thoracic and abdominal wall muscles that compress the abdomen against the diaphragm
Internal intercostal muscles
Rectus Abdominus
Oblique
Transverse Abdominus
Spirometry
The measurement of different air volumes
Respiratory Cycle
one inspiration followed by expiration
Tidal Volume
the amount of air that enters or leaves the lungs during one respiratory cycle
500 ml
Inspiratory Reserve Volume (IRV)
air that can be inspired forcibly beyond the tidal volume
2100-3200 ml
Expiratory Reserve volume (ERV)
air that can be evacuated from the lungs after a tidal expiration
1000-1200 ml
Residual Volume (RV)
air left in the lungs after strenuous expiration
1200 ml
Why do males have greater expiratory rates
because on average males are larger and taller
Vital Capacity (VC)
the total amount of exchangeable air
VC= (TV + IRV + ERV)
males = 4800 ml
Total Lung Capacity (TLC)
SUm of all lung volumes
TLC = (VC + RV)
males = 6000 ml
anatomical dead space
volume of the conducting respiratory passages
150 ml
alveolar dead space
alveoli that cease to act in gas exchange due to collapse or obstruction
Total dead space
sum of alveolar and anatomical dead space
How many breaths per minute do we normally have
roughly 15 breaths/min
Alveolar Ventilation rate (AVR)
measures the flow of fresh gases into and out of the alveoli during a particular time
AVR = frequency (breaths per min) x (TV - dead space)
what type of breathing increases and decreases AVR
Slow deep breathing increases AVR
Rapid shallow breathing decreases AVR
Control of breathing
normal breathing is rthymic and involuntary even though the muscles are under voluntary control
Respiratory Areas
are found in the brain stem
controls breathing by causing inspiration and expiration and by adjusting the rate and depth of breathing
2 groups of medullary rhythmicity center
- Dorsal Respiratory group - integrates peripheral sensory input and modifies VRG rhythms; in control during resting breathing
- Ventral respiratory group - contains rhythm generators whose output drives respiration; forceful breath
Central Chemoreceptors
increase CO2 + H2O -> H2CO3 -> H+HCO3 increase H+ -> Central chemoreceptors -> Respiratory center -> increase BR and increase TV -> more CO2 removed -> decrease H+ in blood decrease O2 -> peripheral chemoreceptors -> respiratory center -> increase BR and TV -> increase O2
Hyperventilation
lowers the amount of Carbon Dioxide in the blood
Alveoli
tiny sacs clustered at the distal ends of alveolar ducts
What does the respiratory membrane consist of
epithelial cells of the alveolus, the endothelial cells of the capillary, and the two fused basement membranes of these layers.
What percentage of Oxygen is carried into the blood?
What does it bind to and what does it produce?
98%
binds to hemoglobin
produces oxyhemoglobin
What factors favor increased diffusion
more surface area; shorter distance; greater solubility of gases; steeper partial pressure gradient
Hypoxia
deficiency of oxygen reaching the tissues
Carbon Dioxide Transport
Carbon dioxide may be transported dissolved in blood plasma as carbaminohemoglobin or bicarbonate ions
What type of cells does carbon dioxide mostly enter
Carbon dioxide mostly enters red blood cells because the enzyme carbonic anhydrase speeds up the reaction
What does the urinary system consist of
2 kidneys, 2 ureters, urinary bladder, urethra
Layers surrounding a kidney
inner layer: fibrous capsule
middle: perirenal fat capsule
Outer: renal fascia
Where do blood vessels, nerves, lymphatic vessels, and the ureter enter the kidney
the renal sinus`
What are the 2 distinct regions found in the kidney
- Renal medulla: houses tubes leading to the papillae
- Renal Cortex: contains the nephrons
What are the functional units of the kidney and what do they do
Nephrons filter the blood
Kidney Functions
- regulates the volume, composition, and pH of body fluids and removes metabolic waste from the blood in the process
- Helps control the rate of red blood cell formation by secreting erythropoietin, and regulates blood pressure by secreting renin
how many nephrons does a kidney contain and what does it consist of
one million nephrons
consists of a renal corpuscle and a renal tubule
Renal corpuscle
is the filtering part of a nephron
is made up of a ball of capillaries called the glomerulus and a glomerular capsule that receives the filtrate
What does urine formation involve
glomerular filtration, tubular reabsorption, tubular secretion
Net Filtration Pressure
the net pressure forcing substances out of the glomerulus
What is the main force responsible for moving substances by filtration through the glomerular capillary wall
it is the hydrostatic pressure of the blood inside
What are the factors that affect the filtration rate
filtration pressure, glomerular plasma osmotic pressure, and the hydrostatic pressure in the glomerular capsule
On average what is the filtration rate
125 ml/min or 180 liters in 24 hours
renin-angiotenson system
regulates sodium excretion
Urinary Elimination
Nephron -> Collecting Duct -> Renal Papilla -> Minor Calyx -> Major Calyx -> Renal Pelvis -> Ureter -> Urinary Bladder -> Urethra -> outside body
Urea and uric acid
Urea is a by-product of amino acid metabolism
Uric Acid is a by-product of nucleic acid metabolism
* urea is passively reabsorbed by diffusion but about 50% of urea is excreted in the urine
* most uric acid is reabsorbed by active transport and a small amount is secreted into the renal tubule
What is urine made of
95% Water
1. Urea
2. Na+
3. K+
4. Phosphate
5. Sulfates
6. Creatinine
7. Uric Acid
Ureter
muscular tubes extending from the kidneys to base of urinary bladder
3 layers of ureter wall
mucous coat, muscular coat, outer fibrous coat
Urinary Bladder
hollow muscular organ lying in the pelvic cavity
Trigone
composed of the openings of the 2 ureters and the urethra
4 coats of the wall of the urinary bladder
inner mucous coat, submucous coat, musclular coat made up of detrusor muscle, and an outer serous coat
Micturition
- Urine leaves the bladder by the micturition reflex
- The detrusor muscle contracts and the external urethral sphincter must also relax
- Stretching of the urinary bladder triggers the micturition reflex center located in the spinal cord
- return parasympathetic impulses cause the detrusor muscle to contract in waves, and an urge to urinate is sensed
- When the contractions become strong enough, the internal urethral sphincter is forced open
- the external urethral sphincter is composed of skeletal muscle and under conscious control
Urethra
a muscular tube that conveys urine from the urinary bladder to the outside via the external urethral orifice
contains urethral glands that secretes mucus into the urethral canal
