animal systems unit test Flashcards
what do we breathe
a mix of nitrogen, oxygen, argon, carbon dioxide, etc.
why do we need oxygen
for body cells to create ATP through cellular respiration which powers growth, movement, and building of new molecules
how does oxygen get to body cells
through gas exchange which occurs in the alveoli of lungs and body cells
name the four key structures in the human respiratory system
a thin & permeable membrane through which diffusion can occur, large surface area for gas exchange, a good blood supply, and a breathing system that brings oxygen rich air
what is the pathway of air
nose/mouth (warmed/moistened; hair and mucus trap and filter dust), pharynx, larynx, trachea (cillia and mucus trap foreign matter), bronchi, bronchioles, alveoli
how and where does gas exchange occur
alveoli; gas exchange happens by diffusion between air in the aveoli and blood flowing in the adjacent capillaries- attatches to RBC with the aid of hemoglobin -> pulmonary vein -> left atrium -> left ventricle
why can diffusion happen rapidly
alveoli are made of a single layer of flattened cells (diffusion distance is small), dense network of capillaries maintain a concentration gradiant for diffusion, high numbers of alveoli, cells in alveoli lining secrete surfactant to allow gasses to dissolve and prevent alveoli from collapsing
what are the key players in regulating breathing
brain (medulla oblongata near base of braine which coordinates breathing movements), diaphragm (sheet of muscle separating thoracic cavity from abdominal cavity), intercostal muscles (between ribs and on inner surface of ribcage
when inhaling what is the difference between air pressure in and out of the body? exhaling?
inhaling; air pressure in lungs is ower than air pressure outside the body so air moves into lungs. exhaling; opposite.
how does the brain regulate breathing
medulla oblongata; concentration of CO2 in blood affects pH- medulla responds to blood pH level when regulating breathing
O2 has less of an effect except at..
high alt. when O2 levels lower, oxygen sensors in AORTA and CAROTID ARTERIES signal medulla to increase breathing rate
what is TV
tidal volume- volume inhaled with each breath at rest
what is IRV
inspiratory reserve volume- additional volume of air that can be taken in beyond regular inhalation
what is ERV
expiratory reserve volume- additional volume that can be forced out of lungs beyond regular exhalation
what is VC
vital capacity- total volume that can be moved in and out of lungs
what is RV
residual volume- amount of air remaining in lungs after full exhalation (prevents collapse of lungs and passageways)
what is the vital capacity equation
VC = TV + IRV + ERV
why do we have a cardiovascular system
transporting gases+nutrients+wastes, hormones, immune cells to fight infection, and to regulate internal body temperature
what happens when you have a fever (not mandatory)
your body senses a change in homeostasis and sends your blood to the surface of your skin to cool down your inner body- it’s why you look flushed and you sweat
what are the two types of circulation
pulmonary (lungs), and systemic (rest of body)
the heart is a…
double pump, delivering oxygen under 2 different pressures to 2 circulations
what is the name of the node that acts as a natural pacemaker, setting your heart rate
the sinoatrial node (SA)
what does the SA do
sends out an electrical signal that spreads through atria, causing them to contract
what is the AV (atrio-ventricular) node’s job in regulating heart beat
after delay (0.1s) at AV node, a signal passes to ventricles where it spreads through ventricle walls, causing them to contract and pump blood into arteries
