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Biology Section Flashcards

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1
Q

tight junctions: function

A

act as a permeability barrier – preventing transport of protein molecules from lumenal side of cell to basolateral side of cell also act to hold neighboring cells together

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2
Q

desmosomes: function

A

hold cells together

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3
Q

Gap Junctions: function

A

provides a mean for water–soluble molecules to pass from the cytoplasm of one cell to the cytoplasm of another cell

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4
Q

type of cells in epidermal region of skin

A

stratified epilthelial cells

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5
Q

Cells that secrete many of the proteins that make up structural connective tissue

A

fibroblasts

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6
Q

Structural proteins secreted by fibroblasts

A

collagen, elastin, reticulin

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7
Q

collagen: features and function

A

–triple stranded, insoluble, fibrous protein –highly cross–linked –quite strong and flexible

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8
Q

reticulin: features and function

A

–thin fiber –not as highly coiled as collagen –found in spleen and lymph nodes

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9
Q

elastin: features and function

A

–highly cross–linked protein –associated with organs that require elasticity (lungs, skin, blood vessels, etc.)

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10
Q

Cartilage: –type of tissue –cell type –where found

A

–connective tissue –special type of fibroblast = chondrocyte –fond in places where stress is put on bodies

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11
Q

bone: –made up of

A

–1/3 organic materials (such as collagen) –2/3 inorganic materials (calcium carbonate, calcium phosphate, etc.)

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12
Q

bone: –what secretes collagen in the bone matrix

A

–Specialized fibroblast cells called osteoblasts

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13
Q

_______ lend(s) flexibility to bones, while ________ lend(s) rigidity

A

–Collagen for flexibility –inorganic cystals for rigidity

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14
Q

Mast Cells

A

–Release histamines in response to an allergic reaction, infection, or injury

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15
Q

Effect of histamines

A

Cause an increase in blood flow to blood vessels in the affected region

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16
Q

Where are mast cells found

A

Respiratory tract, GI tract, etc.

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17
Q

Two types of cells that make up nervous system

A

(1) Nerve cells (neurons) (2) Support cells (glial cells)

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18
Q

Major anatomical features of a neuron

A

(1) Cell Body = integrates info (2) Dendrites = Receive info + Transmit info towards cell body (3) Axon = conducts info away from the cell body

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19
Q

End of a neuron = ______

A

synaptic bulb

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20
Q

Concentration of Na+ and K+ inside vs outside cell

A

IN CELL: small Na+ LARGE K+ OUTSIDE OF CELL: LARGE Na+ small K+

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21
Q

Concentration of Cl– and HCO3– inside vs. outside of cells

A

Cl– = lower inside cell HCO3– = usually lower inside cell also

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22
Q

Typically voltage inside cell (compared to outside). Explain

A

Typically ~ –80mV –negative because of leaky K+ channels – so K+ diffuses outside of cell (down its gradient)

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23
Q

What is the ATPase Pump

A

Pumps Na+ out of the cell and K+ into the cell (against both of their gradients)

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24
Q

Nernst Equation

A

Vio = 2/3 (RT)/(ZF) x log([K+]o/[K+]i)

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25
Q

Steps to generation of an action potential:

A

(1) Stimulus: causes a transient increase in membrane permeability to Na+ (2) Depolarization: caused by Na+ influx (3) Flood of Na+ into cell: will occur if cell is depolarized enough (4) Action Potential: generated by the flood of Na+

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26
Q

High level steps pre and post action potential

A

(1) Stimulus (2) Depolarization –> Action Potential (3) Repolarization: K+ channels open and K+ exits the cell (4) Hyperpolarization: Massive amounts of K+ exit the cell (5) Refractory Period: Na+ channels are temporarily inactive (neuron can’t generate another action potential

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27
Q

The generation of an action potential is an ________ phenomenon, and will always have _______

A

All–or–nothing Will always have the same magnitude

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28
Q

Two factors leading to faster and further action potentials

A

(1) Myelenation (2) Larger neuronal cross sectional area

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29
Q

Glial cells myelenate ________ (part of neuron)

A

Axons

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30
Q

Area on axons where there is no myelin

A

Nodes of Ranvier

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31
Q

Type of glial cell that myelenates the CNS

A

Oligodendrocytes

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32
Q

Type of glial cell that myelenates the PNS

A

Schwann Cells

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33
Q

Nerve impulse in myelenated neurons

A

Referred to as saltatory conduction “Jumps” from node to node along the axons – ions can only enter at the Nodes of Ranvier

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34
Q

How does an action potential spread through neuromuscular junction

A

(1) Action potential reaches synaptic terminal (2) Triggers Ca2+ channels to open – Ca2+ flows into synaptic terminal region (3) Synaptic vesicles fuse with presynaptic membrane – causing release of neurotransmitter (often ACh) into synaptic cleft (4) Neurotransmitter diffuses through the cleft – binding to the postsynaptic membrane receptors (5) Causing receptors to change conformation to a channel – allowing Na+ to flow in (6) Na+ flux in leads to depolarization and action potential

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35
Q

Excitatory vs. Inhibitory Post Synaptic Potentials

A

If lets in Na+ === excitatory If lets in Cl– or K+ ==== inhibitory

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36
Q

How is ACh (Acetylcholine) broken down

A

the enzyme acetylcholinesterase, which is bound to the postsynaptic membrane, hydrolyzes ACh into acetate and choline –Acetate and choline are transported back into the presynaptic terminal where they are used in the synthesis of Ach

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37
Q

Attach bone to muscle

A

tendon

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38
Q

attach bone to bone

A

ligaments

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39
Q

Muscles are made up of multinucleated _______, which are made up of ________, which are made up of ________.

A

Multinucleated Muscle Cells (aka Muscle Fibers) –––> Myofibrils ––––> Sarcomeres

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40
Q

The _______ contain the contractile units of the muscle

A

Myofibrils

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41
Q

the contractile units of the muscle = _____

A

sarcomeres

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42
Q

Sarcomeres are bound by the ________.

A

Z–line

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43
Q

Where there is only actin

A

I–band

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44
Q

the ______ contains all of the myosin

A

A–Band

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45
Q

the ______ is the region in the center of the A–Band, and it only contains myosin.

A

H Zone

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46
Q

Thin contractile protein of sarcomeres = _____ Thick contractile protein = _______

A

thin = actin thick = myosin

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47
Q

_____ are arranged towards the center of the sarcomere (and not attached to the Z–Line)

A

Myosin

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48
Q

Where are myosin heads located

A

In the terminal regions of myosin

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49
Q

Actin filament is composed of a protein subunit called _______ (because the shape is _____).

A

G Actin (G for globular because the shape is roughly spherical)

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50
Q

How can actin filaments grow

A

by the addition of G actin to the ends of already existing filament

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51
Q

Each actin is composed of __________

A

2 rows of G actin monomers wound around each other to form a helix

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52
Q

High level summary of muscle contraction steps

A

(1) ATP is bound to myosin head (so myosin and actin aren’t bound) = relaxed state (2) ATP is hydorlyzed to ADP + Pi ––– myosin undergoes conformational change (3) High energy Myosin–ADP–Pi complex binds to actin (4) Causes release of ADP + Pi from myosin heads –– causing another conformation change of myosin ––––> Actin moves relative to myosin Called the POWER STROKE (5) ATP binds myosin – causing myosin to release actin

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53
Q

What causes myosin to be able to bind actin

A

Tropomyosin is on actin, and covers the myosin binding sites Ca2+ binds to troponin – which is attached to troponin, and causes a conformational change in tropomyosin, uncovering the myosin binding sites on actin

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54
Q

Relationship between action potentials and muscle contraction

A

Action potential travels down T–Tubules, causing release of Ca2+ from sarcoplasmic reticulum into the cytosol (where it can bind to troponin, allowing myosin to bind to actin, allowing for the power stroke)

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55
Q

How Ca2+ in cytosol returns to sarcoplasmic reticulum

A

through Ca2+ –ATPase Pump

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56
Q

Eqn for generation of ATP in aerobic conditions (from glucose)

A

Glucose –––––> CO2 + H20 + 36ATP (slower)

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57
Q

Eqn for generation of ATP in anaerobic conditions (from glucose)

A

Glucose ––––––> Lactate + 2ATP (faster)

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58
Q

During anaerobic conditions, [lactate] begins to ______, which will case the ph to _______. Effects of this.

A

[lactate] increases, and pH decreases –some enzymes can no longer function outside of pH range – halting glycolysis and ATP yield

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59
Q

a grouping of nerve cells = a _______

A

ganglian

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60
Q

CNS = ______ PNS = ______

A

CNS = brain + spinal cord PNS = all nerves extending from the spinal cord

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61
Q

3 divisions of the vertebrate brain

A

(1) Forebrain (2) Midbrain (3) Hindbrain

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62
Q

3 Main subdivisions of the forebrain

A

(1) Cerebrum (2) Thalamus (3) Hypothalamus

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63
Q

The _______ has 2 hemispheres (right and left) which are joined by the ______.

A

Cerebrum (of the Forebrain); joined by the corpus callosum

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64
Q

The Lobes of the cerebrum (and what they are associated with)

A

(1) Frontal = movement and personality (2) Parietal = touch and stretch sensation (3) Temporal = Hearing (4) Occipital = Vision

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65
Q

Outermost layer of the cerebrum = the ______

A

cerebral cortex

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66
Q

The cerebral cortex consists of _______ and ______. Locations of both

A

–gray matter = nerve cell bodies + their dendrites–white matter = myelinated axons of nerve cells White matter is central, gray is on outside”

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67
Q

Location: White and Gray matter in Cerebrum and Spinal cord

A

in Cerebrum: White = Central; Gray = Outside in Spinal Cord: White = Outside; Gray = Central

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68
Q

3 important landmarks in cerebral cortex

A

(1) Central Sulcus = groove; separates frontal + parietal lobes (2) Motor Cortex = Controls movement of individual muscles (3) Sensory Cortex = Detects sensations in various parts of the body

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69
Q

Sensory Homonucleus

A

Schematic model of human being mapped out on the sensory cortex – showing which neurons register sensations from different body parts

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70
Q

Thalamus: function

A

relay station for visual and audio info

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71
Q

hypothalamus: function

A

concerned with visceral activities of the body

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72
Q

pituitary gland: function

A

master endocrine gland –receives info from hypothalamus and sends out info to regulate the body

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73
Q

brainstem: different features

A

*detects movement and can direct the head and eyes towards it –Midbrain: also senses pleasure + pain –Cerebellum: Resposible for the bulk of regulation + coordination of muscular activity –Pons and Medulla: coordinate visceral activities –Reticular Formation: brainstem core; alerts the brain + inhibits motor and sensory impulses that can induce sleep

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74
Q

Muscle that elicits extension (when it contracts) = ______ Muscle that elicits bending/flexing = _____”

A

Extensor Flexor

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75
Q

the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between = _______. Can be mono or poly–synaptic”

A

Reflex Arc –monosynaptic or polysnaptic reflex arcs –can include interneurons (transmit impulses between other neurons)”

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76
Q

efferent vs afferent divisions of the PNS

A

Efferent (AWAY from CNS): Carry nerve impulses: CNS –––––> Muscle Afferent (TO CNS): Carry nerve impulses: Sensory stimuli ––––> CNS

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77
Q

The Autonomic Nervous system is part of the ______ division of the PNS

A

Efferent

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78
Q

One part of the _________ Nervous System is the ___________ Nervous System, which can be divided into the _________ and _________ Systems.

A

Peripheral –––> Autonomic ––––> Sympathetic + Parasympathetic

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79
Q

Where do nerve fibers leave from in the Autonomic Nervous System?

A

Sacral portion of spinal cord; and midbrain and medulla

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80
Q

Key functions of Parasympathetic vs Sympathetic Nervous Systems

A

Parasympathetic = rest and digest Sympathetic = fight or flight

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81
Q

The preganglionic nerve fibers vs. the postganglionic nerve fibers. When long and short.

A

In parasympathetic system: pre = long post = short In sympathetic system: pre = short post = long

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82
Q

What neurotransmitters do different nerve fibers of the parasympathetic and sympathetic systems release?

A

Parasympathetic System: Pre = ACh Pos = ACh Sympathetic System: Pre = ACh Post = Norepinephrine

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83
Q

Cholingeric Nerve Fibers

A

Release ACh (Acetylcholine)

84
Q

Most prominent nerve in parasympathetic division

A

Vagus Nerve ~75% of all neurons in the parasympathetic division are found in the vagus nerve –innervates many organs

85
Q

Sympathetic Division has nerve fibers branching off from

A

Thoracic and Lumbar regions of the spinal cord

86
Q

How adrenal medulla functions

A

(1) Preganglionic nerve fibers from thoracic region of spinal cord (sympathetic division) synapse directly with nerve fibers on the adrenal medulla (i.e., there are no postganglionic nerve fibers) (2) Adrenal medulla is stimulated and releases norepinephrine and epinephrine directly into the bloodstream (thus are hormones) –––> thus it is an endocrine gland *causes increase in HR and pupils to dilate

87
Q

somatic nervous system

A

Part of the PNS related to voluntary movements

88
Q

How somatic nervous system functions

A

(1) Nerve fibers leave CNS and don’t synapse until they reach their effector organ (2) ACh is released (3) Innervating Skeletal Muscle (4) Can be excitatory or inhibitory

89
Q

Some types of sensory receptors (and what they sense)

A

(1) Mechanoreceptors: Pressure; hearing; balance; blood pressure (2) Nocireceptors: Pain (3) Thermoreceptors: cold and warmth (4) Chemoreceptors: Taste, smell, O2, CO2, glucose levels, etc. (5) Photoreceptors (of retina): Photons

90
Q

How sensory receptors receive, transduce, transmit, info

A

(1) receptor receives sensory info (2) Stimulus received changes membrane potential of receptor (transduction) (3) If potential changes enough, an action potential results

91
Q

Adaptation of Sensory Neurons (and which cells adapt a lot and which don’t)

A

Over time, frequency of action potentials diminishes, so can no longer feel the sensation –Pressure Receptors adapt a lot, and pain do not

92
Q

Receptive Field

A

Axonal branches of a single neuron and the many receptors that the branches end at

93
Q

Three Neurons involved in sensory pathways

A

(1) First Order Neurons: Recetive field –––> Spinal cord. Synapses with – (2) Second Order Neurons: Ascend spinal cord to thalamus. (3) Third Order Neurons: Reach specific region of somatosensory cortex

94
Q

Receptor found on postganglionic parasympathetic neuron targets (aka effector organ neurons)

A

Muscarinic Receptors

95
Q

Receptor found on preganglionic parasympathetic neuron targets (aka the postganglionic nerurons)

A

Nicotinic Cholingeric Receptors

96
Q

Receptor found on postganglionic sympathetic neuron targets (aka effector organ neurons)

A

Adrenergic Receptors

97
Q

Receptor found on preganglionic sympathetic neuron targets (aka the postganglionic nerurons)

A

Nicotinic Cholingeric Receptors

98
Q

Nerve Fibers that release norephinephrine (or epenephrine = adrenaline)

A

Adrenergic nerve fibers

99
Q

Receptor found on cells of the adrenal medulla

A

Nicotinic Cholingeric Receptors

100
Q

receptor found on endplates of motor neurons

A

nicotinic cholingeric receptors

101
Q

How to number Carbons

A

Carbon of the Carboxyl Group (COO) = #1

102
Q

autosomal dominant genetic defect

A

if you inherit the gene from one parent you can get the disease

103
Q

Vocab: attenuate” = _____”

A

to reduce

104
Q

Essential Amino Acids in Humans (and mnemonic device)

A

Valine Methionine Histidine Leucine Phenylalanine Threonine Isoleucine Lycine Tryptophan = Very Many Happy Little Pigs Take Iced Lemon Tea

105
Q

What does it mean for a circulatory system to be closed?

A

Blood doesn’t freely mix with body flood

106
Q

High level summary: blood flow starting after returning from tissues

A

“(1) Right Atrium (2) Right Ventricle (3) Pulmonary Artery (4) Pulmonary Veins (5) Left Atrium (6) Left Ventricle (7) Aorta ––> Arteries ––> Arterioles ––> Capillaries*(where nutrient exchange occurs) (8) Venules ––> Veins ––> Superior + Inferior Vena Cava **and then back to right atrium”

107
Q

Arteries = _________ heart Veins = ___________ heart (direction)

A

Arteries = AWAY from heart Veins = TO heart

108
Q

Blood pressure measurement steps

A

(1) Inflate cuff so pressure > Arterial systolic pressure —> artery collapses (stops blood flow) (2) When cuff pressure < Arterial systolic pressure, blood will flow again = “systolic pressure” -will be turbulant flow (b/c high pressure + narrow opening) (3) As relax cuff, turbulant flow will eventually disappear - instead will have laminar (smooth) flow -this is the “diastolic pressure”

109
Q

Arteries are composed of what tissue types? Why?

A

Thick walls composed of smooth muscle and connective tissue (with elastin and collagen) –helps maintain pressure (and not be too high or low)

110
Q

Endothelial cells

A

Blood Vessel Epithelial cells

111
Q

Damage to endothelial cells = ________ Lots of damage results in __________

A

damage = atherosclerosis lots of damage = get hardening of arteries = arteriosclerosis

112
Q

Arteries are important because they represent a major area of _______ in the cardiovascular system.

A

RESISTANCE (thus the strong walls)

113
Q

Sphincter at the entrance to capillary bed; what it is composed of and what it does

A

Precapillary Sphincter –composed of smooth muscle which helps to regulate blood flow to the area

114
Q

What allows blood to flow in only one direction in a vein?

A

Specialized Valves in veins = prevent backflow

115
Q

Varicose beins

A

valve problem in veins; get backflow which increases vein pressure

116
Q

Valve between right atrium and right ventricle

A

Right Atroventricular Valve aka Tricuspid Valve

117
Q

Valve between Right Ventricle and Pulmonary Artery

A

Pulmonary Valve

118
Q

Valve between left atrium and left ventricle

A

Left Atroventricular Valve aka Mitral Valve

119
Q

Valve between left ventricle and aorta

A

Aortic Valve

120
Q

What happens once ventricles are filled with blood

A

–they contract and the AV valves close (preventing backflow) = “lub”

121
Q

What happens as blood flows out of the pulmonary artery and aorta

A

Pulmonary and Aortic Valves close = “dub”

122
Q

What causes the “lub” and “dub” heart noises?”

A

“lub” = AV valves closing “dub” = Pulmonary and Aortic valves closing

123
Q

Why don’t the AV valves invert

A

b/c of tendinous cords = chordae tendinae which hold them in place

124
Q

What is the major pacemaker of the heart

A

Sinoatrial Node (SA Node)

125
Q

What happens if the SA node is damaged

A

AV node will take over and slow the heart rate to ~40bpm

126
Q

Where impulse travels from SA Node

A

SA Node ––> Atroventricular Node (AV Node) ––> Bundle of His, which causes ventricles to contract and eject blood

127
Q

Negative Feedback loop when blood pressure is too low

A

Stimulus: Decrease in arteriol pressure –which means less stretch on arteries––> ––baroreceptors sense this and send impulses to medulla and brainstem––> –––medulla activates sympathetic nervous system––> ––––Impulses sent (via sympathetic system) cause norepinephrine (or epinephrine) release at SA Node––> –––––SA Node increases heart rate ––––––Increasing heart contractions –––––––Increasing Blood pressure

128
Q

Cardiac Output

A

=Blood Pumped Per Minute –by each of the ventricles in Liters/Min Cardiac Output = (Stroke Volume)*(Heart Rate) liters/min = (liters/beat)*(beat/min)

129
Q

Eqn for Poiseuille’s Law

A

Flow = ΔPπ(R^4)/(8ηL) = (P1–P2)*π(R^4)/(8ηL) where η = viscosity ΔP = Pressure drop from 2 ends of tube R = Radius of tube L = length of tube

130
Q

4 key takeaways from Poiseuille’s Law

A

(1) Flow is proportional to R^4 –––> VERY dependent on radius! (2) Flow is proportional to the inverse of L –––> short tubes = faster flow (3) Flow is proportional to the inverse of η –––> High viscosity = slower flow (4) ΔP is what drives blood flow in the cardiovascular system

131
Q

How does temperature affect diffusion

A

Increase Temp ––> Increased Energy ––> Increased Diffusion

132
Q

Fick’s Law Eqn

A

J = –(D)(A)(ΔC/Δx) = –DA(Cout – Cin)/Δx Where J = net rate of diffusion (usually mol/s) ΔC/Δx = concentration gradient

133
Q

Concentration of pure water

A

55.5 mol/L

134
Q

What happens to the concentration of water when you add solutes? Why?

A

It will decrease (from 55.5 mol/L) because solute is taking up space water was taking up

135
Q

How does the concentration of water change when adding one mol of glucose vs one mol of NaCl. Why?

A

One mol of NaCl will displace twice as much water – because it will ionize to Na+ and Cl– meaning that it will take up twice as much space, and decrease water’s concentration by twice as much

136
Q

What is an osmol

A

1 mol that doesn’t ionize

137
Q

1 M NaCl soln = ______ osmol/L

A

2 osmol/L

138
Q

Osmolarity

A

The total solute concentration of a solution

139
Q

What is osmotic pressure (aka πosm) –and explain in terms of the semipermeable membrane experiment

A

The amount of pressure that stops osmosis –osmosis will occur until the added pressure (on the side of the tank with the added protein, due to the added volume) offsets the change in concentration (since water molecules will flow to the side with the higher osmolarity – the right side, through the semipermeable membrane)

140
Q

Hydrostatic Pressure

A

the difference in H2O levels from one side of the semipermeable membrane to the other, Δh, which is a direct measurement of the osmotic pressure

141
Q

Purpose of the lymphatic system

A

Collects excess fluid that leaks into the interstitial space from capillaries and returns it back to the circulatory system via the vena cava

142
Q

Purpose of lymph nodes

A

filter out foreign particles that could cause disease

143
Q

What happens if a lymph node is blocked? –How does this occur after heart surgery?

A

Edema results = increase in interstitial fluid –after heart surgery: heart can’t pump blood fast enough –> backup in veins –> backup in lymphatic system ––– as a result, edema occurs – particularly in swollen ankles and legs (fluid pools there due to gravity)

144
Q

Hydrostatic pressure in the capillaries forces fluid from ________––> _________ ––> _________

A

Capillaries –––> Interstitial Space –––> Lymphatic Capillaries

145
Q

Blood clotting occurs via a ______ which allows for _______.

A

Cascade Process allows for amplification

146
Q

The two different pathways in blood clotting

A

Intrinsic Route - due to contact with some abnormal surface (e.g., “internal” damage to the blood vessel) Extrinsic Route - due to trauma of the tissue (e.g., blood vessel breaks and goes outside of the blood vessel or “external”)

147
Q

Many of the factors involved in blood clotting are called _________

A

serine proteases

148
Q

Staring with Factor Xa, describe the high level cascade leading to blood clotting

A

(1) In presence of Factor Xa (as well as Va, an auxiliary factor); prothrombin (which ws converted from preprothrombin –––> thrombin (2) Thrombin converts: fibrinogen –––> fibrin (3) Fibrin forms the blood clot (needs transglutimase in order to be converted to crossed–linked fibrin clot in order to do the clotting)

149
Q

How is preprothrombonin converted to prothrombin

A

A Carboxylase enzyme (carboxylates Glu residues) –the enzyme requires Vitamin K+ and HCO3–

150
Q

Why is preprothrombin converted to prothrombin?

A

B/c Prothrombin is a good chelating agent = it has a high affinity for Ca2+ (which is essential for blood clotting)

151
Q

How do blood platelets bind the factor necessary in the blood clotting?

A

The negative charge on phospholipid heads on blood platelets allows γ–carboxyglutamate residues on prothrombin to bind via Ca2+ –Factor Xa also has γ–carboxyglutamate residues and also binds. Xa then cuts prothrombin releasing thrombin

152
Q

Why fibrinogen must be converted to fibrin

A

fibrinogen is large and soluble with a large negative charge (which will cause repulsion) –must release some of the negative charges (as fibrinopeptides) to get to insoluble fibrin, which has a +5 central charge (in addition to still negative charged ends) –––> now can have aggregation of fibrin monomers with one another (leading to fibrin clot)

153
Q

Soft clot vs Hard clot (in blood clotting)

A

Soft Clot = initial fibrin clot Hard Clot = there is a cross–linking via the enzyme transglutaminase (to get cross–linked fibrin clot)

154
Q

Once a damaged area has been repaired via blood clotting, what happens

A

Plasmin (a serine protease) hydrolyzes regions in fibrin clot to dissolve it into smaller fragments (removing clot) –Tissue Plasminogen Activator (TPA) converts plasminogen to plasmin

155
Q

What is dicoumarol

A

Vitamin K antagonist – causes abnormal prothrombin that doesn’t bind to Ca2+

156
Q

What is warafarin

A

Vitamin K antagonist – causes hemorrhaging in rats and mice

157
Q

High Level summary of how air passes down respiratory tract

A

(1) Oral cavity (2) Pharynx (3) Larynx (4) Trachea (5) 2 Bronchi (one to each lunch) ––– > Lungs: (6) Many bronchioles (7) MANY MANY alveoli

158
Q

respiration

A

process by which oxygen is brought to the cells of tissues and CO2 is removed as a waste product

159
Q

Composition of an alveolus 2 factors leading to fast diffusion

A

Each alveolus consists of a single layer of epithelial cells juxtaposed to a very thin basement membrane 2 factors of fast diffusion –epithelial layer and endothelial layer of capillaries are barely separated –have millions of alveoli (large surface area)

160
Q

Atmospheric Pressure at sea level = ______

A

760 atm

161
Q

Rough makeup of Atmospheric Pressure (by molecule)

A

78% N2 21% O2 0.3% CO2 0.7% H2O

162
Q

How to calculate partial pressures

A

Multiple the % of the pressure a molecule/gas makes up by the total pressure (partial pressures are INDEPENDENT of one another)

163
Q

Why does the Partial Pressure of O2 decrease at altitude?

A

TOTAL pressure decreases (but O2 is still 21% of the total)

164
Q

What does it mean if a gas is at equilibrium with a liquid

A

The # molecules dissolving into the liquid is the same as the # of molecules leaving the liquid ––> the partial pressure of the molecule/gas is the same in the gas phase as in the liquid

165
Q

Total pressure of any gas is proportional to ________________.

A

Its concentration of molecules in the air.

166
Q

What is the total pressure of air acting on membranes of epithelial cells in the alveoli of the lungs equal to?

A

The sum of the total partial pressures of all gases in the air

167
Q

Structure of respiratory tract – how foreign objects leave the tract

A

Epithelial cells line lumen of passageways to bronchioles and have cilia which beat upwards. –also have mucus secreating glands. **cilia beat moving mucus and foreign objects trapped in mucus upward to oral cavity where its swallowed by reflex.

168
Q

How does smoking affect respiratory system

A

–it decreases cilia activity while also decreasing the body’s defense against lung infections by bacteria

169
Q

Type of tissue that lines upper and lower respiratory tract (and how that impacts function)

A

Upper passageways = maintain openings by cartilage rings Lower down (bronchioles, for ex) = smooth muscle instead

170
Q

diaphragm –type of tissue –location

A

Skeletal muscle separating thoracic cavity and abdomen

171
Q

Pleural membranes involved in breathing What is in between them

A

Visceral Pleura = covers lungs Parietal Pleura = adheres to diaphagm in between = intrapleural space = contains watery fluid

172
Q

How does breathing occur (beginning with muscle contraction)

A

Rib Cage muscles contract and pull rib cage up+out while diaphragm muscles pull the diaphragm downward –––> thus enlarging thoracic cavity ––> causes pleural membranes to move via suction – expanding lungs, creating subatomic pressure in alveoli ––> allowing for inspiration –when stop contracting, tissue returns to normal length and air in alveoli is forced out = expiration”

173
Q

What would happen to the lungs without connection to visceral pleura?

A

lungs would collapse

174
Q

What allows for diffusion of Oxygen to capillaries and CO2 to alveoli?

A

Pressure differences between capillaries and alveoli

175
Q

The greater the pressure differences, the more diffusion there is of O2 from ________ –> __________ CO2 from _________ –> _________

A

O2: blood in capillaries –> tissue cells CO2: tissue cells –> blood in capillaries

176
Q

How is oxygen carried in the blood

A

Mostly through hemoglobin; a little through diffusion

177
Q

hemoglobin

A

transport protein in red blood cells – transports O2

178
Q

Structure of hemoglobin

A

quaternary structure –has 4 polypeptide subunits ––each has a heme group with a Fe2+ in the center ––in total can bind 4 O2

179
Q

What happens to O2 solubility in blood due to hemoglobin?

A

When hemoglobin takes up O2, more O2 can leave gas phase in alveoli and enter the blood – thus increasing O2 solubility in blood

180
Q

How saturated is hemoglobin in the capillaries? –How much of this O2 does hemoglobin give up to tissues?

A

98% saturated with O2 in capillaries –only gives up ~25% to tissues

181
Q

what happens to the O2 dissociation curve of hemoglobin when pH is decreased? –one example of when this cold occur

A

Curve shifts down and right –ex: exercise

182
Q

–what happens to the O2 dissociation curve of hemoglobin when 2,3–BPG (a byproduct of glycolysis) binds to hemoglobin? –one example of when this cold occur

A

Curve shifts down and right –ex: O2 deprivation

183
Q

What happens when hemoglobin O2 dissociation curve shifts?

A

Shifts down and right = causes hemoglobin to release more O2 to tissues at the same PO2

184
Q

How is CO2 carried in the blood?

A

(1) 70% – in HCO3– form (2) 20% – on hemoglobin (3) 10% – dissociated in plasma and red blood cells

185
Q

How does CO2/HCO3– conversion occur in tissues

A

(1) CO2 diffuses into RBC where it is converted to H2CO3 via carbonic anhydrase (2) H2CO3 ionizes to H+ and HCO3– (3) HCO3– diffuses into blood plasma and is carried to capillaries of lungs by circulatory system

186
Q

How does CO2/HCO3– conversion occur in the lungs?

A

(1) HCO3– diffuses into RBC where it combines with H+ and becomes H2CO3 (2) H2CO3 is converted to CO2 via carbonic anhydrase (3) CO2 diffuses into blood plasma and then diffuses into capillaries and then to the alveoli

187
Q

What part of the brain coordinates breathing

A

Brainstem – particularly medulla and pons

188
Q

How do medulla and pons coordinate breathing

A

Δ[H+] and Δ[CO2] –––> affect chemosensitive areas of medulla and Δ[O2] is sensed by chemoreceptors of cartoid arteries and aorta arch–––> –transmit signals to brainstem *nerve impulses from medulla and pons cause respiratory muscles to contract

189
Q

bronchioles are innervated by ___________ nerves

A

Parasympathetic

190
Q

What is asthma

A

hypersensitivity to airborne antigens –––> spasm and constrict smooth muscles of bronchioles

191
Q

The total cross sectional area of ________ is the largest of all types of vessels in the cardiovascular system

A

all the capillaries

192
Q

_______ regulate the flow of blood throughout the body

A

areterioles

193
Q

Blood pressure has the highest velocity and the highest pressure when __________

A

After exiting the left ventricle

194
Q

______________ measures turbulant flow.

A

Reynold’s Number. Usually turbulant when Re > 2000

195
Q

Reynold’s Number Equation

A

Re = vdp / n where v = velocity d = vessel diameter p = density n = viscosity

196
Q

Which walls are stronger: arterial walls or vein walls Which are more distensible

A

ARTERIAL walls are stronger thus VEIN walls are more distensible

197
Q

Which walls are less distensible – systemic artery walls or pulmonary artery walls? Why?

A

Systemic Artery Walls B/c they are under more pressure and thus less distensible

198
Q

what is the effect of blood centrifugation?

A

Separates plasma and Red Blood Cells –with a buffy coat in between (made up of WBC and platelets)

199
Q

What is the ames test?

A

Ames test for mutagens: Mix suspected mutagen (a chemical) with bacteria (as well as, for example, liver extract), incubate, and see if many mutated colonies appear. If they do, the suspected mutagen is in fact a mutagen.

200
Q

How many rings do purines and pyrimidines have?

A

Purines have 2 rings Pyrimidines have 1 ring

201
Q

What about the SA node allows for it to be a pacemaker

A

Gradual depolarization – called pacemaker potential – which brings the membrane potential to threshold, when an action potential can occur

202
Q

Alkane and alkene chemical formulas

A

Alkane = CnH2n+2 Alkene = CnH2n

203
Q

Phosphorylation = the addition of _______

A

Phosphate: PO4 3–

204
Q

Acetylation = the addition of

A

Acetate: C2H3O2–

205
Q

Carboxyl Group (chemical formula)

A

COOH

206
Q

The heart rate is controlled by ____

A

Medulla Oblongata

MCAT (14 decks)

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