Module 3 Exam Review Flashcards
Myelin
a sheath that wraps around the axon, provides insulation, accelerates propagation of action potentials
- oligodendrocytes in CNS, schwann cells in PNS
Glia
non neuronal cells within CNS, role in immunity and protection
astrocytes
connects neuron to capillary
grey matter
unmyelinated neurons, cell bodies, dendrites, glia
white matter
myelinated neurons
forebrain
collecting sensory information
hindbrain
control of movement
midbrain
interprets, helps hindbrain decide how to respond to forebrain
afferent information
signals that go to the CNS
efferent information
sends signals from CNS to the rest of the body
Divisions of the peripheral nervous system
1: autonomic: involuntary processes
somatic: voluntary
2: autonomic splits
sympathetic: fight or flight
parasympathetic: rest and digest
Neural plasticity
changing how neurons communicate/interact
Neuronal receptor
the cell sensing the stimuli is also a neuron
non-neuronal receptor
a sensory cell receptor separate from the neuron
Chemosensing
reecptors that bind to specific chemicals
Electrosensing
sensing using electric fields
Magnetosensing
sensing using earths magnetic field
detecting visible light
photoreceptors at the back of the eye called rods and cones absorb specific types of light
Mechanoreceptors
neurons that respond to physical stimuli
statocytes
contains statoliths which sends signals to neurons to promote a change in orientation
essential amino acid
an amino acid that an animal cannot synthesize but must be obtained from food
vitamins
organic molecules required in small amounts, serve as coenzymes
Minerals
inorganic nutrients that cannot be synthesized in the body
overall tasks of the digestive system(5)
- mechanical processing and motility: movements that break up, mix, and propel food material
- secretion: release of digestive enzymes into the lumen
- Digestion: breakdown of food into smaller particles then into nutrient molecules small enough to be absorbed
- Absorption: passage of digested nutrients and fluid across the tube wall into the blood or lymph
- elimination: expulsion of undigested and unabsorbed residues
most animals use ___________ to increase digestion
endosymbionts
intracellular digestion
hydrolytic enzymes break down food inside vacuoles
- dominant in eukaryotes
extracellular digestion
breakdown of food in compartments continuous with the outside of the animals body
Carbohydrate digestion
oral cavity to small intestine
Protein digestion
stomach to small intestine
Nucleic acid digestion
small intestine
fat digestion
small intestine
evolution of gut complexity
blind sacs- unidirectionality fermentation chambers regionalization surface area cellular specialization
appetite-regulating hormones
- secretion of ghrelin triggers feeling of hunger
- rise in blood sugar triggers insulin secretion which suppresses appetite
- leptin is produced by fat tissue suppresses appetite
- PYY secreted by small intestine after meals acts as an appetite suppressant
open circulatory system
blood cells can move from vessels to interstitial fluid
- fluid is continuously exposed to entire body
closed circulatory system
blood is confined to vessels and is distinct from interstitial fluid
- more control/ better filtration
most complex separated oxygenated and deoxygenated blood
main types of blood vessels
arteries, veins, capillaries
cardiac output
volume of blood pumped per minute by each ventricle
Stroke volume x heart rate
heart rate
frequency of heart contraction
stroke volume
volume of blood pumped by a heart ventricle in a single contraction
pacemaker
- sinoatrial node
- set of auto rhythmic cells
- cardiac action potential spreads through gap junction across ventricles of the heart allowing for coordinated contraction
sequence of electrical events in heart
- signals from SA node spread through atria
- signals are delayed at AV node
- Bundle branches pass signal to heart apex
- signals spread throughout ventricles
systolic pressure
blood pressure in arteries during ventricle contraction
diastolic pressure
blood pressure in the arteries when the ventricles are relaxed
Circulatory fluids
Non-cellular fractions(50-60%)
Plasma - osmotic balance
Cellular fractions(40-50%)
Leukocytes - defence and immunity
Platelets- blood clotting
Erythrocytes - transport of O2
the rate of diffusion is __________ to surface area and ________ to the distance through which the molecules must move
proportional
inversely proportional
features of respiratory organs
- moist surfaces in which gases dissolve and diffuse
- increased surface area
- extensive blood flow
- thin, delicate structure
counter current exchange
exchange of a substance between 2 fluids flowing in opposite directions
- more oxygen can be picked up as water moves closer to the source of O2
positive pressure breathing
a breathing system in which air is forced into the lungs
inhalation and exhalation (when pressure increases or decreases)
inhalation: muscles contract to enlarge thoracic cavity, pressure drops and air is sucked in
exhalation: diapragm relaxes, thoracic cavity is compressed, pressure increases and air is pushed out
tidal volume
volume of air a mammal inhales and exhales with each breath
- negative pressure from diaphragm contraction inflates the lungs
vital capacity
maximum volume of air that a mammal can inhale and exhale with each breath
residual volume
amount of air that remains in the lungs after forceful exhalation
homeostatic control of breathing
blood pH falls due to rising CO2 levels
-medulla detects pH decrease and signals rib muscles and diaphragm to increase rate and depth of ventilation
Cooperativity
once one oxygen subunit binds, the affinity for another one to bind is increased
- explains lag on oxygen vs saturation graph
oxygen from hemoglobin is unloaded in response to …(4)
- low pO2
- low pH
- warm temperatures
- metabolites
innate immunity
defences made in advance of the threat, on stand-by to offer immediate defence (nonspecific)
- physical barriers -skin, acidic stomach
- soluble factors-(cytokines act as alarm signals in possible breech of barriers)
- phagocytosis- in the case the intruder causes damage, recognizes something it should eat
- inflammation- indicates where the problem lies, causes vasodilation in middle and vasoconstriction on other sides
PPR’s
- pattern recognition receptors
- bind and recognize PAMP’s
PAMPs
pathogen associated molecule patterns
- innate response to generic bacteria specific molecules
Natural killer cells (NK cells)
- destroys cells infected with viruses
- destroys foreign or altered cells such as tumour cells
- similar to cytotoxic T cells but do not require antigens to be displayed
Phagocytosis
process used by protists to engulf solid particles by the cell membrane to form an internal food vacuole
- involved in obtaining nutrients or removing pathogens in the immune system
Adaptive immunity
vertebrate specific defence that is mediated by B cells and T cells
lysozyme
an enzyme that destroys bacteria cell walls in mammals
hemocytes
immune cells of insects
how an organism obtains carbon(2)
autotrophs: use CO2 as a carbon source and can carry out fixation
heterotrophs: cannot fix carbon and therefore must synthesize carbon compounds
how an organism obtains energy(2)
Phototrophs: organisms that use light as their energy source (do photosynthesis)
Chemotrophs: obtain energy from organic or inorganic molecules
Digestive system
body cavity or tube in which food is reduced to particles small enough to be absorbed into the internal environment
Alimentary canal
anterior end- ingestion
middle portion- storage and initial digestion
parietal cell
cell in the stomach that secretes acid
path of food through the digestive system
oral cavity pharynx esophagus epiglottis stomach duodenum jejunum ilium large intestine
absorption in the small intestine
absorption of vitamins and minerals,
- contains villi and microvilli for surface area and absorption
- pancreas secretes enzymes to break down fat
large intestine
- site for water reabsorption
- lots of bacteria live here
single loop circulatory system
- entire system is 1 loop(no gravity to worry about)
- doesn’t generate much pressure, 1 weak pump
3 chambered heart
- most reptiles
- 2 atria, 1 ventricle
- some mixing of oxygenated and deoxygenated blood
4 chambered heart
- gravity means the heart has to be strong
- higher metabolic rate means more energetic demands
capillaries
- 1 cell thick, between arterioles and venules
- high surface area
- controlled by vasodilation or vasoconstriction
Red blood cells
- bags of hemoglobin
- binds and carries oxygen
- each has an Fe containing heme group
fetal hemoglobin
- has to bind oxygen more tightly to steal from maternal circulation
Myoglobin
- in muscle
- binds o2 more tightly
- single subunit (no cooperative binding)
oxygen dissociation curve
- shifts right when tissue is working, decrease blood pH, increasing temperature
- shifts left at the lungs, wanting to bind, increases blood pH, decreases temperature
how blood pressure is maintained
vasoconstriction or vasodilation of blood vessels
bronchioles
surrounded by circular muscle to dilate or constrict passage of air
alveoli
site of gas exchange, 1 cell thick
immune response
the ability to recognize foreign or dangerous macromolecules and eliminate them
lymphocytes
T-cells - pass through the thymus - cytotoxic T-cells bind with foreign antigens and kill them - recognize diseased cells B-cells - generate antibodies - bone cells
B-cell response
- produce anti-bodies against antigen
- antibodies bind to antigen containing cells and inhibit them
- activated b-cells multiply
T-cell response
- helper T cell differentiates pathogens
- cytotoxic t cells migrate to infection site, binds to the pathogen-infected cell and kills it
antibodies
highly specific immunoglobin proteins that recognize and bind to specific antigens
antigen
molecule specifically recognized as foreign or dangerous by cells of the immune system
adaptive/ specific immunity
- specific pathways induced in response to pathogens
- slower than innate but more specific
- APC brings antigen to adaptive immune response
hypertonic vs hypotonic solution
hypertonic: having greater solute concentration(hypoosmotic)
hypotonic: having lesser solute concentration(hyperosmotic)
osmolarity
property of a solution (all osmotic solute)
tonicity
solutions effect on cell volume
osmoregulators
maintain constant internal osmolarity
osmoconformers
internal osmolarity changes to environment
Euryhaline
tolerate wide ranges of external osmolarity
stenohaline
tolerate narrow ranges of external osmolarity
kidney
collection of nephrons that filter blood to remove nitrogenous waste(urea)
