Respiration Flashcards
diaphragm
dome-shaped skeletal muscle between the thoracic and abdominal cavities
very thin tissue
xiphoid attached to lower ribs
pleura
slippery, double-layered membrane that covers the viscera within the thoracic and abdominal cavities and lines the walls of thorax and abdomen
visceral pleura
clings to the surface of the lungs
parietal pleura
lines the chest walls, covering the superior surface of the diaphragm
pleural cavity
in between the two pleural layers, filled with a small amount of lubricating fluid
trachea
tubular passageway for air
how do vena cava, sort and oesophagus go through diaphragm
3 holes:
foramen for inferior vena cava (in central tendon)
foramen for aorta (at bottom of diaphragm)
foramen for oesophagus
what type of muscle forms diaphragm
skeletal muscle - voluntary control of breathing (important for i.e. speaking)
active breathing
depends on diaphragm
assisted by movement of rib cage
what happens to the diaphragm when we inhale (breathe in)
diaphragm goes down 2-3 vertical levels
true ribs
upper ribs
1-7
articulate with the sternum via costal cartilages (attached to sternum)
false ribs
lower ribs
8-10
they do not articulate with the sternum
they articulate with costa cartilage above
floating ribs
last 2 ribs
11-12
not in contact with the sternum, floating
joint between vertebral head and head of rib
synovial joint
joint between transverse process and tubercle of rib
synovial joint
intercostal space
spaces between ribs
layers of intercostal space (3)
external, internal and innermost intercostal muscle
external intercostal muscle
2 handles
bucket handle pulls ribs upwards and outwards
pump handle sternum moves upwards and forwards
internal intercostal muscle
for exhalation
pulls ribs backwards and downwards
inhalation
chest expands, diaphragm contracts and goes down 2-3 vertical levels
exhalation
chest contracts, diaphragm relaxes and goes up 2-3 vertical levels
extreme breathing
involves rib cage, diaphragm
involves muscles of neck and trunk as accessory muscles of respiration
why do lungs expand
when the chest expands, the parietal pleura is pulled outwards due to the tensions between the parietal and visceral pleuras caused by the fluid in between
how many breaths needed to recycle the air
5 - with each breath, 20% of air is exchanged
why do lungs contract
they contain a vast network of elastic fibres
after expansion, the lung wants to return to original form and size
lung resting size
size of a fist/tennis ball
regardless of exhalation/inhalation
respiratory epithelium functions
lines the respiratory tract
moistens and protects the airways
barrier to potential pathogens and foreign particles
prevents infection and tissue injury by mucociliary clearance
cells that form the respiratory epithelium
ciliated pseudostratified columnar epithelium
goblet cells that contain mucus granules to secrete mucus
mucus
helps maintain epithelial moisture
traps particles and pathogens moving through the airway
mucus layers
watery layer humidifies air - sheet is moved by cilia
sticky layer cleans the air - particles stick to this layer
how is air that come in airways heated
by blood vessels underneath the cells
what lines the internal nose (nose cavity)
lined with muscle and mucous membrane
nasal septum
vertical portion that divides the nasal cavity into right and left
what are paranasal sinuses
cavities lines with mucous membrane that are continuous with the lining of the nasal cavity - drain mucus
paranasal sinuses
ethmoid labyrinth and maxillae (maxillary sinus)
conchae
bones surrounded by curved holes so the air, when it enters through the nostrils, spins and the dust particles are thrown to the mucus lining
they increase surface area of internal nose
divisions of conchae
superior, middle and inferior - extend put of each lateral wall of the nasal cavity
vestibule
where the air passes first when entering the nostrils
lines by skin containing coarse hairs that filter out large dust particles
olfactory epithelium
made up of olfactory receptor cells, supporting cells and basal cells
contains cilia but not goblet cells.
