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
what is an ECG/EKG and what does it do
electrocardiogram- detects electrical activity of heart through electrodes placed on body surface
what does it mean when they say the heart is myogenic
that the heart beats on its own, but note the nervous system is involved and can affect heart rate
what nerves can bring electrical impulses to the heart
sympathetic and vagus, from the medulla oblongata
where does the hormone epinephrine come from
adrenal glands (reside on top of kidneys)
what does low blood pressure indicate
low O2 and low pH- heart needs to speed up
what does high blood pressure mean
high O2 and high pH- heart needs to slow down
what is blood comprised of
55% plasma; fluid portion of blood- mostly water + protein and other dissolved substances (NO CELLS), 45% cellular components; RBC + WBC, platelets
define blood pressure
force that blood exerts on the walls of blood vessels
define systolic pressure
max pressure during contractions of ventricles (occurs during systole when blood is pumping OUT of heart)
define diastolic pressure
lowest pressure BEFORE ventricles contract (occurs during diastole when ventricles are filling with blood)
what does a sphygmomanometer measure
blood pressure (cuff is inflated to exert pressure on the brachial artery, which is measured)
what is cardiac output and what is its formula
volume of blood pumped out by heart (mL/min); indicator of level of O2 being delivered to body. Cardiac Output = HR x SV (heart rate, stroke volume
what is HR and SV
HR; bpm. SV; stroke volume, which is how easily heart fills with blood (strength of contraction of ventricles)
what is CVF
cardiovascular fitness; capacity of lungs, vessels to deliver O2 to working muscles.
define atherosclerosis
sclerosis/narrowing in vessels leads to restricted BF, increase in pressure in the artery which leads to damage to the arterial wall. damaged area is replaced with fibrous tissue which reduces elasticity. lesions form in lining called atherosclerotic plaques. if plaque ruptures, continuous blood clotting, formng a thrombus that restricts BF. if thrombus is dislodged it becomes an embolus that can cause a blockage in a smaller arteriole. atherosclerosis can lead to coronary disease in coronary arteries.
define a heart attack
when a coronary artery becomes completely blocked, an ACUTE MYOCARDIAL INFARCTION. without enough O2 + glucose, heart muscle cells cant make ATP, and then they cannot contract. heart spasms and may stop beating. treated by by-pass or creating a stent (balloon angioplasty)
what are the four types of tissue
muscle, connective, epithelial, nerve
what are the five steps of digestion
ingestion, digestion, absorption, assimilation, elimination
what are the 3 salivary glands
parotid, sublingual, submandibular
what are the 3 purposes of the stomach
disinfect food with HCl, store food (2L max), digest protein using pepsin
what stops the stomach from digesting itself
mucus secreted by stomach cells protects lining
is bile mechanical or chemical digestion
mechanical
what are the accessory organs for digestion
gallbladder, pancreas, liver
what vitamin is absorbed in the colon
vitamin K, produced by E-coli bacteria in large intestine
what are feces comprised of
cellulose from plants, roughage/fiber, masses of bacteria + water
what do carbs break down into
poly + disaccharides in mouth, simpler sugars w help of pancreatic amylase, simple sugars w help of small intestine enzymes
what does protein break down into
polypeptides with pepsin, then amino acids with trypsin and chymotrypsin
what do fats break down into
smaller droplets with the help of bile, then glycerol + fatty acids with lipases
what does biuret indicate
bluish-purple = polypeptides (many amino acids linked together). lavender-pink = amino acids.
what does benedict’s reagent indicate
when heated turns red/orange/yellow in presence of glucose
what does iodine indicate
blue-black = starch (polymer of glucose)
what does litmus indicate
blue = base (buttermilk), pink = acid (fatty acid)
