Midterm 3

Question 1

What are the 4 tissue types?

Answer 1

-connective tissue
-nervous tissue
-muscle tissue
-epithelial tissue

Question 2

How is the connective tissue described?

Answer 2

-cells arranged in a liquid, jelly-like or solid matrix
-can be found in bones, cartilage, ligaments, blood
-each CT secretes distinct ECM

Question 3

How is the nervous tissue described?

Answer 3

-neurons & supporting cells
-helps respond to environment

Question 4

How is the muscle tissue described?

Answer 4

-three types of muscle tissues: skeletal muscle, cardiac muscle, & smooth muscle
-body movement
-pumping blood
-movement of food & vessel size

Question 5

How is the epithelial tissue described?

Answer 5

-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

Question 6

What is homeostasis?

Answer 6

-the stability in the chemical & physical conditions within an organism’s cells, tissues & organs

Question 7

What are the 4 ways of exchanging heat?

Answer 7

-conduction, convention, radiation, & evaporation

Question 8

What is conduction?

Answer 8

direct transfer of heat between 2 physical bodies

Question 9

What is convention?

Answer 9

heat exchanged between a solid & a moving liquid or gas

Question 10

What is radiation?

Answer 10

the transfer of heat between 2 bodies that are not in direct physical contact

Question 11

What is evaporation?

Answer 11

phase change that occurs when a liquid becomes a gas

Question 12

What is the difference between endothermy vs exothermy?

Answer 12

-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)

Question 13

What is the homeostatic system & what is the order?

Answer 13

-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

Question 14

What are the main functions of the kidney?

Answer 14

-regulates water
-regulates the amount of ions (electrolytes)
-filters the blood by taking out toxic waste

Question 15

How does ADH regulate the amount of water in the urine?

Answer 15

-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

Question 16

Where does kidney filtration occurs & how does it work?

Answer 16

-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

Question 17

What is osmoregulation?

Answer 17

-the process by which organisms try to control the concentration of water & solutes in their bodies

Question 18

What are the similarities & differences between osmoregulation of seawater, freshwater & land organisms?

Answer 18

-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

Question 19

What is hypertonic, hypotonic & isotonic?

Answer 19

-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

Question 20

Where is the osmotic gradient in the nephron & how it functions?

Answer 20

-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

Question 21

What is the function of kidney reabsorption?

Answer 21

-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

Question 22

What is the collecting duct?

Answer 22

-determines how much water gets out of the body based on hormones

Question 23

Where are different nutrients are digested & absorbed?

Answer 23

-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

Question 24

What are the differences between essential & non-essential nutrients?

Answer 24

-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

Question 25

How does food move down the esophagus?

Answer 25

by a wave of muscle contractions called peristalsis propels food down the esophagus

Question 26

What are the differences between incomplete & complete digestive tracts?

Answer 26

-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

Question 27

What is the path of blood flow into, through & out of the heart?

Answer 27

-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

Question 28

What is systolic & diastolic pressure?

Answer 28

-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)

Question 29

What is the path that CO2 takes once generated by tissue?

Answer 29

-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

Question 30

What is the gas law? How does it affect oxygen & carbon dioxide in & out of the body?

Answer 30

-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

Question 31

What is partial pressure for the air we breath?

Answer 31

-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

Question 32

What is the path that electrical current takes through the heart?

Answer 32

• 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

Question 33

What is reflex actions?

Answer 33

reflex response: an involuntary response to an environmental stimulus

Question 34

What is resting potential & how does the sodium-potassium pump creates it?

Answer 34

-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

Question 35

What is the sequence of events in an action potential?

Answer 35

-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

Question 36

What are the steps & location of neurotransmission?

Answer 36

-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

Question 37

What are the 6 types of sensory systems & what they can detect?

Answer 37

-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

Question 38

What are the sequence of events that lead to muscle contractions?

Answer 38

-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