Midterm 3 Flashcards
What are the 4 tissue types?
-connective tissue
-nervous tissue
-muscle tissue
-epithelial tissue
How is the connective tissue described?
-cells arranged in a liquid, jelly-like or solid matrix
-can be found in bones, cartilage, ligaments, blood
-each CT secretes distinct ECM
How is the nervous tissue described?
-neurons & supporting cells
-helps respond to environment
How is the muscle tissue described?
-three types of muscle tissues: skeletal muscle, cardiac muscle, & smooth muscle
-body movement
-pumping blood
-movement of food & vessel size
How is the epithelial tissue described?
-covers outside of the body, lines inner surface of organs & forms glands
-often act as a barriers or protective layers
-apical = faces outwards
-basolatoral = faces inward & connected to ECM of basal lamina
What is homeostasis?
-the stability in the chemical & physical conditions within an organism’s cells, tissues & organs
What are the 4 ways of exchanging heat?
-conduction, convention, radiation, & evaporation
What is conduction?
direct transfer of heat between 2 physical bodies
What is convention?
heat exchanged between a solid & a moving liquid or gas
What is radiation?
the transfer of heat between 2 bodies that are not in direct physical contact
What is evaporation?
phase change that occurs when a liquid becomes a gas
What is the difference between endothermy vs exothermy?
-endotherms produce adequate heat to warm its tissues (warm blooded; humans, need to eat more)
-exotherms rely on heat gained from their environments (cold blooded; reptiles, doesn’t need to eat as much)
What is the homeostatic system & what is the order?
-order: sensor -> integrator -> effector
-sensor: structure that senses some aspect of the external or internal environment
-integrator: evaluates the incoming sensory information by comparing it to the set point & determines whether a response is necessary to achieve homeostasis
-effector: any structure that helps restore the internal condition being monitored by the system
-negative feedback: occurs when effectors reduce or oppose the change in internal conditions
-summary example: external stimuli (heat or cold); sensors: record the temperature-> integrator: is body temp below or above set point? -> effector: shivers -> negative feedback: stops shivering when warm enough
What are the main functions of the kidney?
-regulates water
-regulates the amount of ions (electrolytes)
-filters the blood by taking out toxic waste
How does ADH regulate the amount of water in the urine?
-it reabsorbs water in collecting duct & increases water in blood
-occurs when we are dehydrated so when it’s released it up regulates aquaporins therefore water can come out easily
Where does kidney filtration occurs & how does it work?
-nephrons: where the kidney filtration occurs
-its made up 4 areas
-renal corpuscle: filtration occurs (like a sieve)
-proximal tubule: involved in reabsorption of the “good material” back into the bloodstream
-loop of henle: involved in osmotic gradient that helps with reabsorption of water & sodium
-distal tubule: hormonal control of how much water goes out of the body
-collecting duct: collection of urine & removal of it
What is osmoregulation?
-the process by which organisms try to control the concentration of water & solutes in their bodies
What are the similarities & differences between osmoregulation of seawater, freshwater & land organisms?
-seawater: hyper-osmotic to shark (high solute in sea relative to tissue)
-freshwater: hypo-osmotic to bass (low solute in freshwater relative to tissue)
-land animals are also hyper-osmotic
What is hypertonic, hypotonic & isotonic?
-hypertonic= more concentration outside cell so it goes in -> cell bursts
-hypotonic= low concentration outside cell so it goes out -> cell shrink
-isotonic= same concentration both ways
-tonicity= determines the direction in which osmosis occurs
-osmosis= diffusion of water across a semipermeable membrane
Where is the osmotic gradient in the nephron & how it functions?
-it’s in the loop of henle
-descending loop= reabsorbs more water
-reabsorb ions in ascending loop
-get more water out of our filtrate
-as you go down the concentration of salt increases
What is the function of kidney reabsorption?
-create an ion gradient that is low in sodium so the sodium will rush in & bring with it chloride, glucose & vitamins & at the same time let those diffuse out & let water diffuse out; reabsorbing them
What is the collecting duct?
-determines how much water gets out of the body based on hormones
Where are different nutrients are digested & absorbed?
-carbohydrates: mouth & lumen of small intestines
-lipids: mouth & lumen of small intestines
-proteins: stomach & lumen of small intestines
-absorbed: in epithelium of small intestines into bloodstream
What are the differences between essential & non-essential nutrients?
-essential: those that cannot be synthesized & must be obtained from the diet
-non-essential: can be made by the animal’s body from other substances
How does food move down the esophagus?
by a wave of muscle contractions called peristalsis propels food down the esophagus
What are the differences between incomplete & complete digestive tracts?
-incomplete: have a single opening, the mouth, through which the animal both ingests food & eliminates waste; the mouth opens into a chamber called a gastrovascular cavity, where digestion takes place
-complete: allows for ingestion, digestion absorption & waste removal; it’s a whole system & tract
What is the path of blood flow into, through & out of the heart?
-blood comes to the right atrium from the body, moves into the right ventricle & pushed into the pulmonary arteries in the lungs
-after picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle & out of the body’s tissues through the aorta
What is systolic & diastolic pressure?
-systole= contraction (your ventricles contract forcing blood into vessels going to your lungs & body; right ventricle contracts a little before the left one does)
-diastole= relaxing (ventricles relax & are filled with blood coming from the upper chambers)
What is the path that CO2 takes once generated by tissue?
-majority of the carbon dioxide created in our tissues is converted to bicarbonate that travels through the bloodstream then reconverted to co2 in the lungs
What is the gas law? How does it affect oxygen & carbon dioxide in & out of the body?
-gas molecules move from high pressure to low pressure
-oxygen binds to hemoglobin -> goes to where it needs to be -> then unloaded off the hemoglobin & released to be used
-majority of the carbon dioxide created in our tissues is converted to bicarbonate that travels through the bloodstream then reconverted to co2 in the lungs then released
What is partial pressure for the air we breath?
-Dalton’s Law of Partial Pressure: total pressure of a mixture of gasses is equal to the sum of the individual pressures
-we want to move gas from high pressure to low pressure
What is the path that electrical current takes through the heart?
- sinoatrial node -> atrioventricular node -> atrioventricular bundle -> interventricular septum > right & left bundle branches -> purkinje fibers -> ventricular walls
-SA node -> AV node -> AV bundle -> IV septum -> R & L bundle branches -> purkinje fibers -> ventricular walls
What is reflex actions?
reflex response: an involuntary response to an environmental stimulus
What is resting potential & how does the sodium-potassium pump creates it?
-sodium ions= positive ; potassium ions= negative
-more positive sodium ions outside (0 mV) & more potassium ions inside (-70 mV)
-changes in ion potentials between outside & inside & that change always leads to a more negative inside & more positive / zero on the outside
-sodium-potassium pump help maintain resting potential
-sodium-potassium pump creates it where its more positive (sodium) on the outside & more negative (potassium) on the inside
What is the sequence of events in an action potential?
-phase 1= depolarization, phase 2= repolarization, phase 3= hyperpolarization
-step 1: resting potential = -70 mV
-step 2: stimulus
-step 3: opening of sodium channels (high on the outside)
-step 4: sodium ions diffuse into the cells & membrane potential increases (+3)
-step 5: as sodium rushes in, we will reach +30 mV, at the high end sodium channels close
-step 6: potassium channels open up
-step 7: potassium ions diffuse out (heading to -70)
-step 8: once it reaches -70, potassium channels close
What are the steps & location of neurotransmission?
-step 1: action potential comes down
-step 2: calcium comes in
-step 3: stimulates the release of neurotransmitters which then bind to the post-synaptic channels, then there is a rush of ions into the post synaptic neuron, ion channels then close
What are the 6 types of sensory systems & what they can detect?
-mechanoreceptors: detect pressure changes
-photoreceptors: detect light
-chemoreceptors: detect chemicals
-thermoreceptors: detect heat
-electroreceptors: detect electricity; humans can’t do this
-magnetoreceptors: detect earth’s magnetic fields; humans can’t do this, knows the least amount
What are the sequence of events that lead to muscle contractions?
-units of muscle fibers = sarcomeres
-each sarcomere contains parallel overlapping thin (actin) & thick (myosin) filaments
-muscle contracts when these filaments slide past each other, resulting in a shortening of the sarcomere & the muscle
-muscle contractions are initiated when muscle fibers are stimulated by a nerve impulse & calcium ions are released
-the troponin units on the actin myofilaments are bound by calcium ions
-binding displaces tropmyosin along myofilaments which exposes the myosin binding sites
-the head of each myosin unit is bound to ADP & phosphate molecule
-release phosphates & bind to actin myofilaments via the binding sites
-2 myofilaments glide past one another, head- first powered by chemical energy stored in their heads
-as they move, they release the ADP
-gliding motion is halted by ATP, when it breaks the bonds between myosin & actin
-then ATP is broken to ADP + phosphate
-cycle repeats
