Midterm Study Deck Flashcards

Question

Peptide Bond

Answer 1

* Forms between carboxyl end of one amino acid and amino end of the next amino acid

Answer 2

* A polymer of 3–100 amino acids

Answer 3

* Amino acide sequence * Stabilized by peptide bonds

Answer 4

* How the chain is oriented in space * Alpha helix * Beta pleated sheets * Stabilized by hydrogen bonds

Answer 5

* Three-dimensional shape how proteins twist and fold * Stabilized by a combination of covalent bonds, ionic bonds, hydrophobic interactions, and hydrogen bonds * Creates polar and nonpolar areas within the protein molecule

Answer 6

* Two or more polypeptide chains are joined.

Answer 7

permanent disruption of protein structure leading to loss of biological function

Answer 8

o Store genetic information o Nucleic acids are long chains (polymers) containing monomer subunits known as nucleotides o Two types of nucleic acids  DNA: deoxyribonucleic acid  RNA: ribonucleic acid

Answer 9

o DNA contains the instructions for producing RNA

Answer 10

o RNA contains the instructions for producing proteins o RNA is shorter, representing only the segment of DNA that codes for one or more proteins

Answer 11

 Building blocks (monomers) of nucleic acids o Each nucleotide contains  Five-carbon sugar * Deoxyribose (in DNA nucleotides) * Ribose (in RNA nucleotides)  Nitrogenous base * A,G,C,T,U  Phosphate group

Answer 12

 Adenine-Thyamine (double bonded)  Cytosine-Guanine (triple bonded)

Answer 13

* A-Uracil (double bonded) * G-C (triple bonded)

Answer 14

o More “primitive” o Internal environment of cell is not divided into membrane-bound compartments o Prokaryotes Lack a Nucleus and Organelles  Prokaryotes include all organisms in the domains Bacteria and Archaea  Prokaryotic cell structure consists of: * Plasma membrane * Cytoplasm * Genetic material is not enclosed by a membrane * No membrane-bound organelles  Prokaryotic cells are generally smaller than eukaryotic cells

Answer 15

o Internal environment is divided into membrane-bound compartments called organelles o Eukaryotes Have a Nucleus, Cytoplasm, and Organelles  Eukaryotes include human and all other animals, plants, fungi, and protists  Eukaryotic cell structure includes: * Plasma membrane * Nucleus o Membrane-bound genetic material * Cytoplasm o Internal cell contents, excluding the nucleus o Includes soft gel-like fluid called cytosol * Organelles o Variety of membrane-bound structures within the cytoplasm with specialized functions

Answer 16

o Magnifies up to 1000x o Can be used to view living samples

Answer 17

o Magnifies up to 100 000x  Can reveal internal details of cell structure

Answer 18

 Magnifies up to 100 000x  Provides three-dimensional view of cell surface

Answer 19

Controls the cell, information centre Contains DNA. Large, spherical organelle in the cell. Appears with multiple pores on the surface. Contains a smaller sphere within it o Double-layered nuclear membrane o Nuclear pores: permit passage of RNA and proteins o Chromosomes: D N A (genetic information) o Nucleolus: site of synthesis of ribosome components

Answer 20

Synthesize proteins - Composed of RNA and protein - Role of ribosomes: site of protein synthesis - Location o Free: floating in cytoplasm  These ribosomes synthesize proteins for immediate use in the cell o Bound: attached to outer surface of endoplasmic reticulum  These ribosomes synthesize proteins that will be transported to other organelles or exported from the cell

Answer 21

manufacturing center (calcium storage, protein synthesis, lipid metabolism) Layered and ruffled membranous structure continuous with the nuclear membrane. Dotted with ribosomes. - Highly folded membranous network - Two types of endoplasmic reticulum (E R) o Rough E R (has ribosomes on surface)  Attached ribosomes manufacture proteins which may be modified in the E R, particularly those that will be secreted from the cell o Smooth E R (no ribosomes on surface)  Lipid synthesis, including the synthesis of some hormones  Packaging of proteins and lipids for delivery to Golgi apparatus

Answer 22

Refines, packages, and ships Large organelle consisting of stacks of flattened membranous sacs and tubules - Refines synthesized products - Serves as packaging and shipping center - Products are packaged into vesicles and shipped to other locations within the cell or to the cell membrane for export

Answer 23

Membrane bound storage and stripping centers Small Spherical vesicle that has fused with the inside of the plasma membrane.

Answer 24

Provide energy (powerhouse of the cell) Oval or kidney shaped organelle that is filled with a matrix of ruffles. - Surrounded by a double membrane - Inner membrane is highly folded, more surface area - Divides mitochondria into:  Inner compartment  Outer compartment - Site of cellular respiration - Utilizes O2 and produces CO2 - Generates (36-38) ATP—a quick source of energy

Answer 25

Synthesis of ribosomal subunits A small, dense spherical structure in the nucleus

Answer 26

Controls movement of materials into and out of the cell. Description, Outer edge and barrier of the cell

Answer 27

Semifluid gel material inside the cell The region between the plasma membrane and the nucleus.

Answer 28

Destroys cellular toxic waste. Small, spherical vesicle.

Answer 29

Microtubular structures involved in cell division Two bundles of long rods.

Answer 30

Structural framework of the cell. Long, thin filaments found throughout the cell.

Answer 31

Digests damaged organelles and cellular debris. Small Spherical vesicle.

Answer 32

Long term energy source o Triglycerides o Long-term energy storage in animals o Stored in cytoplasm of fat cells

Answer 33

Short term energy source o Carbohydrate storage o Short-term energy storage in animals o Stored in cytoplasm of muscle cells and liver cells

Answer 34

Internal scaffolding - helps maintain cell shape - Cytoskeleton is composed of: o Microtubules: tiny hollow tubes of protein o Microfilaments: thin solid fibers of protein o Microtubules and microfilaments form framework that supports the cell  Much like tent poles support a tent o Cytoskeleton also supports and anchors other cellular structures

Answer 35

specialized for movement o Short, many o Found on cells lining airways and certain ducts

Answer 36

specialized for movement o Long, single o Enable spermatozoa to swim

Answer 37

Surrounds the cell - Separates a cell from its environment - Is selectively permeable o Permits movement of some substances into and out of the cell, but blocks others - Enables transfer of information between environment and cell The Plasma Membrane Is a Lipid Bilayer - Plasma membrane is composed of: o Phospholipids: two layers (bilayer)  Polar heads face outside and face the cytoplasm  Nonpolar tails meet in center o Cholesterol: increases mechanical strength o Proteins: provide means of transport through membrane for molecules and for information - Nonrigid

Answer 38

cell does not need to expend energy for this o Diffusion o Osmosis o Facilitated diffusion o a type of cellular transport in which substances such as ions and molecules move down their respective concentration gradients.

Answer 39

cell must expend energy Bulk transport o Involves membranous vesicles to move larger substances  Endocytosis  Exocytosis - the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy. - Requires a membrane protein (transporter) - These proteins are sometimes called “pumps” - Requires A T P or other energy source

Answer 40

movement of molecules from a region of high concentration to a region of low concentration - Requires that there be a concentration gradient - A difference in concentration between two points - High concentration → low concentration - When the concentration of a substance is the same throughout a solution—it has reached equilibrium - Diffusion is only effective in the body over short distances (across membranes, within cells)

Answer 41

Diffusion of water across a selectively permeable membrane * Water moves from an area of low solute concentration to an area of high solute concentration * Water moves down its own concentration gradient * Osmotic pressure: fluid pressure required to stop or oppose osmosis

Answer 42

* Small lipid soluble substances can move directly through the phospholipid bilayer without the assistance of a channel or transporter protein * Transport of small, uncharged, nonpolar molecules

Answer 43

* Protein channels span the membrane and enable the transport of some molecules * Size, shape, and electrical charges of amino acids lining the channel determine what molecules can pass through o Some always open o Others are “gated”—the channel can open or close under certain conditions o Examples of substances transported: - (osmosis) - Ions

Answer 44

* Also referred to as facilitated diffusion * Binding of a specific molecule to a membrane transport protein triggers a change in the shape of the protein which then carries the molecule through the membrane bilayer * Transporter proteins are highly selective for specific substances * Examples of substances transported: o Glucose o Amino acids

Answer 45

Active Transport * Transports sodium out of the cell * Transports potassium into the cell * Both ions are transported against their concentration gradient

Answer 46

brings substances into the cell o A substance in the extracellular environment is surrounded by the cell’s plasma membrane and internalized, forming a membrane-bound vesicle o Some vesicles are selective and have receptors for specific substances  Example: transport of insulin into cells

Answer 47

expels substances from the cell o Substance is contained within a membranous vesicle, which then fuses with the plasma membrane, releasing the substance to the external environment o Release of wastes, indigestible material, secretion of special products

Answer 48

relative concentration of solutes in two fluids

Answer 49

o Extracellular and intracellular solute concentrations are equal. o Cells maintain a normal volume in isotonic extracellular fluids. o Regulatory mechanisms maintain extracellular fluid that is isotonic with intracellular fluid

Answer 50

o Extracellular solute concentration higher than intracellular solute concentration (OUTSIDE HIGHER THAN INSIDE) o Water will diffuse out of cell (osmosis)—moving toward the higher solute concentration o Cell may shrink and die

Answer 51

o Extracellular solute concentration lower than intracellular solute concentration (OUTSIDE LOWER THAN INSIDE) o Water will diffuse into cell (osmosis)—moving toward higher solute concentration o Cell may swell and burst

Answer 52

* Energy in glucose is used to generate A T P. * One glucose molecule may yield 36 A T P. * A T P can then be used to do cellular work., more readily used

Answer 53

the breakdown of glucose in the presence of oxygen to yield A T P - Four stages of cellular respiration - Glycolysis - Preparatory step - Citric acid cycle - Electron transport system and oxidative phosphorylation

Answer 54

1% of total energy reserves - Can be rapidly catabolized to glucose, which then participates in cellular respiration

Answer 55

78% of total energy reserves - Triglycerides have twice the energy of an equal amount of carbohydrates

Answer 56

21% of total energy reserves - Have the same amount of energy as an equal amount of carbohydrates

Answer 57

Made when cellular respiration doesn't have oxygen, pyruvate will build up which converts to lactic acid. Build up in muscle causes burning sensation. - In the absence of oxygen, glycolysis is the only ATP-producing step available. Glycolysis without oxygen results in lactic acid buildup.

Answer 58

- Earliest organisms were unicellular - Unicellular organisms consist of just one cell - Unicellular organisms depend on their immediate external environment which may vary extensively

Answer 59

- Consist of many cells - Larger size - Able to seek out or maintain a favorable external environment - Cells specialize and contribute to the well-being of other cells

Answer 60

- groups of specialized cells that are similar in structure and perform a common function - Several types of tissue may be grouped to form an organ * Four primary tissues - Connective tissue - Epithelial tissue - Muscle tissue - Nervous tissue

Answer 61

* Organized as sheets of cells that line or cover various surfaces and body cavities, one or more layers * Ex. Skin, mouth lining, inner surfaces of digestive tract, lungs, bladder, blood vessel and kidney tubules * Two basic purposes * Protection, secretion, and absorption

Answer 62

 Epithelial cells adapted to form glands  Glands: epithelial tissues specialized to synthesize and secrete a product

Answer 63

(exo- means “outside” or “outward”) * Secrete their products into a hollow organ or duct. Examples of exocrine glands are the glands in your mouth that secrete saliva, glands in your skin that excrete sweat, and glands in your stomach that produce digestive acid.

Answer 64

* Secrete substances called hormones into the bloodstream. One endocrine gland is the thyroid gland, which secretes several hormones that help regulate your body’s growth and metabolism.

Answer 65

 Flattened cells  Forms outer surface of the skin  Line blood vessels, lungs, mouth, throat

Answer 66

 Cube-shaped cells  Form lining of kidney tubules, glandular tissue

Answer 67

 Column-shaped (tall, rectangular) cells  Line digestive tract, certain reproductive organs, larynx  May include goblet cells that secrete mucus

Answer 68

 Adapted for diffusion across cell barriers  Line glands, and respiratory, digestive, reproductive systems

Answer 69

 Provide protection, as in the skin surface

Answer 70

- Noncellular layer directly beneath epithelial tissue - Composed of proteins secreted by epithelial cells and connective tissue - Provides structural support to overlying cells - Attaches epithelial layer to underlying connective tissue

Answer 71

- Supports the softer organs of the body against gravity - Connects the parts of the body together - Stores fat - Produces the cells of blood * Matrix provides the strength * Two general types - Fibrous - Specialized

Answer 72

* Function: provides strength, support, and elasticity * Contains fibers and cells embedded in matrix * Cells: fibroblasts, macrophages, lymphocytes, and neutrophils * Fibers: collagen, elastic, and reticular

Answer 73

* Collagen fibers: strong, slightly flexible * Elastic fibers: thinner, can stretch * Reticular fibers: thin interconnective fibers of collagen - Provide internal structural framework for soft organs (liver, spleen, lymph nodes)

Answer 74

produce and secrete proteins that form the fibers (collagen, elastin)

Answer 75

* Functions: - Transitional tissue from which bone develops - Maintains shape of nose and ears - Protects and cushions joints and vertebrae * Structure: - Dense connective tissue of collagen fibers * Slow to heal when injured - There are no blood vessels in cartilage, so the mature cells (called chondrocytes) obtain their nutrients only by diffusion through the ground substance from blood vessels located outside the cartilage. Consequently, cartilage is slow to heal when injured.

Answer 76

* Contains relatively few living cells * Matrix (ground substance) composed of calcium phosphate * Does it contain blood vessels? o Unlike cartilage, bone contains numerous blood vessels, and for this reason it can heal within four to six weeks after being injured.

Answer 77

* Plasma: cells suspended in a fluid matrix * Cells: derived from stem cells in bone marrow * Cell types include: - Red blood cells: transport oxygen and nutrients to body cells and carry away the waste products of the cells metabolism. - White blood cells: Found in the immune system to defend the body. Platelets: Participate in the mechanisms that cause blood to clot following an injury

Answer 78

* Function: fat storage * Adipocytes: fat cells store fat in vacuoles * Location of adipose tissue: - Under the skin - Around internal organs * Beneficial roles: - Insulation - Cushioning * Weight loss reduces size of individual adipocytes but does not necessarily reduce their number

Answer 79

* Muscle cells shorten or contract, producing movement * Muscle cells are called muscle fibers - Long, thin - Arranged parallel to each other

Answer 80

* Connect to tendons which attach to bone * Contract (shorten) to move body parts * Composed of thousands of individual muscle fibers (cells) arranged in parallel * Fibers have multiple nuclei * Voluntary—under conscious control * Activated only by nerves * 600 skeletal muscles

Answer 81

* Located only in the heart * Shorter cells, blunt-ended, one nucleus per cell * Gap junctions: allow direct electrical connections between adjoining cells * Enable coordinated contraction of entire heart * Involuntary: heart contracts rhythmically entirely on its own

Answer 82

* Surrounds hollow organs and tubes - blood vessels - digestive tract - uterus - bladder * Slim cells tapered at ends * One nucleus per cell * Gap junctions enable coordinated contraction * Involuntary

Answer 83

Consists primarily of cells that are specialized for generating and transmitting electrical impulses throughout the body. It forms a rapid communication network for the body. Nervous tissue is located in the brain, the spinal cord, and the nerves that transmit information to and from various organs.

Answer 84

specialized nervous system cell - Function: generate and transmit electrical impulses - Structural components  cell body: nucleus and most of the cytoplasm  dendrites: cytoplasmic extensions from cell body, receive signals from other neurons  axon: transmits electrical impulses long distances

Answer 85

- Function:  Surround and protect neurons  Provide nutrients to neurons

Answer 86

- Structures composed of two or more tissue types joined together; perform specific functions

Answer 87

- Groups of organs that together serve a broad function that is important to survival either of the individual organism or a species.

Answer 88

- Whole Front of body - Divided by diaphragm into:  Thoracic cavity  Two pleural cavities (each contains a lung)  Pericardial cavity (encloses the heart)

Answer 89

 Pelvic cavity: lower part of abdominal cavity

Answer 90

Back of head: Cranial + Vertebral

Answer 91

- Midsagittal  Divides body into left and right sides - Frontal  Divides body into front and back - Transverse  Divides body into top and bottom

Answer 92

at or near front

Answer 93

at or near back

Answer 94

nearer to any point of reference, usually the body trunk

Answer 95

farther away from a point of reference

Answer 96

situated above or directly upward

Answer 97

situated below or directed downward

Answer 98

includes skin, hair, nails, glands * Protection from dehydration (helps prevent our bodies from drying out) * Protection from injury (such as abrasion) * Defense against invasion by bacteria and viruses * Regulation of body temperature * Synthesis of an inactive form of vitamin D * Sensation: provides information about the external world via receptors for touch, vibration, pain, and temperature

Answer 99

- Outer layer of skin - Multiple layers of stratified squamous epithelial cells - Continually replaced by dividing cells at base of epidermis - No blood vessels

Answer 100

Provide structural integrity to the epidermis. It produces a tough waterproof protein called keratin.

Answer 101

 Located near the base of the epidermis, produce a dark brown pigment called melanin, which is then picked up and stored by the nearby keratinocytes.  Protects us against the suns ultraviolet radiation, exposure to sunlight increases melanocytes activity

Answer 102

- Primarily dense connective tissue  Collagen, elastic, reticular fibers - Lies underneath the epidermis - Supports tissues

Answer 103

- Shaft above the skin surface - Root below surface in the hair follicle - Follicle: sheath of several cell layers that supports the root

Answer 104

- Attached to hair follicle, Why? o Contracts when you are frightened or cold, causing your hair to become more erect

Answer 105

- Secrete sebum, which moistens and softens skin

Answer 106

- Secrete sweat to help in temperature regulation - Contains antimicrobial peptide that protects against bacteria

Answer 107

- Supply nutrients, remove waste, assist in temperature regulation

Answer 108

- Detect heat, cold, touch, deep pressure, vibration

Answer 109

Constancy of the conditions within the internal environment * Multicellular organisms devote a significant portion of their metabolic activities to maintaining homeostasis Homeostasis Is Maintained by Negative Feedback

Answer 110

Deviations from normal are detected and counteracted * Components of a negative feedback control system * Controlled variable: any physical or chemical property that might vary and must be controlled to maintain homeostasis * Sensor (receptor): monitors current value for controlled variable and sends information to control center * Control center: receives input from sensor, compares value to set point, signals the effector if necessary * Effector: takes action to correct the imbalance, based on information from the control center

Answer 111

* Relatively uncommon in living organisms * A change in a controlled variable causes a series of events that amplifies the original change * Example: Childbirth, once labor has started the child must be born to end the positive feedback loop * Positive feedback is NOT a mechanism for maintaining homeostasis

Answer 112

* Muscle tissue is found in every organ * Muscles participate in every activity that requires movement * All muscle cells have one mechanism of action – They contract, then relax * Large proportion of body weight is muscle – 40% of body weight in males – 32% of body weight in females

Answer 113

conscious control over movement (picking up a pen)

Answer 114

unconscious control over movement (beating of heart)

Answer 115

act around a moveable joint to produce motion similar to or in concert with agonist muscles. They often act to reduce excessive force generated by the agonist muscle and are referred to as neutralizers

Answer 116

The muscle that works in the opposite direction as that of the primary muscle or agonist muscle, which is engaged in some activity.

Answer 117

Muscle to bone attachment Composed of tough connective tissue containing collagen Tears and other injuries are very slow to heal

Answer 118

Bundles of muscle fibers (cells) wrapped with connective tissue (fascia)

Answer 119

contractile unit of myofibrils A sarcomere is a segment of myofibril extending from one Z-line to the One myofibril within one muscle cell may have 100,000 sarcomeres arranged end to end

Answer 120

Forms thick filaments Myosin filaments are in middle of sarcomere, between actin filaments

Answer 121

Forms thin filaments Actin filaments are linked to Z-line

Answer 122

Attachment points for sarcomeres

Answer 123

* Muscle contraction: each sarcomere shortens a little * Basic process of contraction * Skeletal muscle must be activated by a nerve impulse * Nerve activation increases the concentration of calcium ions in the vicinity of the contractile proteins * Presence of calcium ions enables contractions * When nerve stimulation stops, contraction stops

Answer 124

* Acetylcholine (neurotransmitter) is released from motor neuron at neuromuscular junction. * Acetylcholine diffuses across neuromuscular junction to muscle cell receptors. * Binding of Acetylcholine to muscle cell receptors generates electrical impulse within muscle cell. * Electrical impulse is transmitted through the cytoplasm.

Answer 125

* Activation Releases Calcium * Electrical impulse triggers calcium ion release. * Calcium is released from sarcoplasmic reticulum (modified smooth endoplasmic reticulum). initiates chain of events that cause contraction when it contacts the myofibrils. 1. Calcium is released from sarcoplasmic reticulum. 2. Calcium binds to troponin. 3. Troponin–tropomyosin complex shifts position. 4. Myosin binding site on actin is exposed. 5. Myosin heads form cross-bridges with actin. 6. Myosin heads bend, pulling actin filaments toward center of sarcomere. 7. Sarcomere shortens. 8. Muscle cells shorten. 9. Muscle shortens (contracts).

Answer 126

Sliding filament mechanism

Answer 127

Heads of myosin molecules (thick filaments) do not contact actin (thin filaments)

Answer 128

Myosin heads form cross-bridges between thin and thick filaments  Myosin heads bend, pulling actin filaments toward center of sarcomere  This process happens repeatedly, shortening the sarcomere * Thousands of myosin cross-bridges form and myosin heads bend, moving actin filaments relative to the myosin filaments. * Hundreds of thousands of sarcomeres shorten, shortening muscle cells and the entire muscle.

Answer 129

the troponin–tropomyosin blocks the site on actin where myosin heads can bind

Answer 130

the troponin–tropomyosin complex shifts, exposing myosin binding sites on actin filaments, enabling cross- bridge formation

Answer 131

– ATP required for contraction  Provides energy to energize myosin head, form cross-bridge, and undergo bending. – ATP required for relaxation  Provides energy to detach myosin head from actin. * As long as Ca is present, cycle of ATP breakdown, myosin binding, bending, and detachment occurs repeatedly and sarcomere shortens. * Nerve impulse ends, energy from ATP breakdown is used to actively transport Ca back to sarcoplasmic reticulum, enabling relaxation.

Answer 132

Whether bones move – Degree of nerve stimulation – Type of muscle fiber – Muscle mass – Aerobic capacity

Answer 133

– Resistance training – Builds more myofibrils, particularly in fast-twitch fibers – Increases muscle mass and strength

Answer 134

– Activities that cause body to increase oxygen intake – Builds endurance – Increases blood supply to muscle cells – Increase in mitochondria and myoglobin

Answer 135

* Involuntary—no conscious control * Able to contract entirely on their own in absence of nerve stimulation * Contraction is influenced by autonomic nervous system * Cardiac muscle: – Cardiac muscle cells are joined by intercalated discs – Have gap junctions allowing cells to electrically stimulate adjacent cells – Pacemaker cells: cardiac muscle cells that set the pace of contractions

Answer 136

Cardiac muscle – Sarcomere arrangement of thick and thin filaments – Striated appearance * Smooth muscle – Filaments arranged in criss- crossed bundles, not sarcomeres – No striations, no sarcomeres

Answer 137

Skeletal muscle: fastest * Cardiac muscle: moderate * Smooth muscle – Very slow – Partially contracted all of the time – Almost never fatigues

Answer 138

refers to a group of genetic diseases that cause progressive weakness and degeneration of skeletal muscles – Genetic disease: Duchenne muscular dystrophy – Modified dystrophin protein enables leakage of Ca++ into cells – Extra Ca++ activates enzymes that destroy muscle proteins – Muscle weakening and wasting – Muscle mass is replaced with fibrous connective tissue – Life expectancy: approximately 30 years

Answer 139

An infection caused by bacteria called Clostridium tetani – Bacterial infection of a wound by Clostridium tetani – Bacteria produce tetanus toxin – Death due to respiratory failure – Preventable by tetanus vaccine

Answer 140

a sudden, unexpected tightening of one or more muscles

Answer 141

when a muscle is stretched too much and part of it tears

Answer 142

Hard elements of the skeleton Hard, rigid appearance due to nonliving extracellular crystals of calcium minerals * Bones are living tissue containing several types of cells involved in bone formation and remodeling * Five important functions of bone * Support * Protection * Movement * Mineral storage * hematopiesis - Stability - homeostasis

Answer 143

Dense fibrous connective tissue  Attach bone and bones in a synovial joint * Made of dense fibrous connective tissue * Provide strength in joints yet enable movement

Answer 144

Specialized connective tissue, fibers of collagen and elastic in a gel-like ground substance  Cushions vertebrae  Reduces friction in joints

Answer 145

contains marrow space  Yellow bone marrow (mostly fat) in marrow space

Answer 146

trabeculae form lattice-like support in ends of long bones  Spaces may contain red bone marrow  Red marrow contains stem cells which produce red blood cells, white blood cells, platelets

Answer 147

connective tissue covering of bone – Contain Osteoblasts – Generate new bone during growth and repair

Answer 148

bone-forming cells

Answer 149

cellular arrangement found in compact bone – Extracellular deposits of calcium phosphate enclosing living cells (Osteocytes)

Answer 150

Osteocytes arranged in rings called osteons (Haversian systems)

Answer 151

Blood Vessels

Answer 152

– Fibrocartilage  Intervertebral disks between vertebrae  Menisci in knee joints – Hyaline  Forms embryonic structure, which later forms bone  Covers and protects ends of long bones in joints, providing protection, reducing friction – Elastic cartilage  Flexible  Outer ear, nose, epiglottis

Answer 153

* Early fetal development: cartilage models form – Formed by chondroblasts (cartilage-forming cells) * Later fetal development: osteoblasts replace cartilage with bone Long bones continue to lengthen during childhood * Growth occurs at growth plate * Bones may also grow in diameter as osteoblasts deposit bone beneath the periosteum

Answer 154

changes in shape, size, strength * Weight-bearing exercise increases overall bone mass and strength

Answer 155

cells that degrade bone to initiate normal bone remodeling and mediate bone loss in pathologic conditions by increasing their resorptive activity

Answer 156

cells that form new bones and grow and heal existing bones

Answer 157

is loss of bone mass due to prolonged imbalance of osteoblast and osteoclast activity

Answer 158

These bones are longer than they are wide and have a shaft with two ends. Examples include the femur, humerus, and radius.

Answer 159

These bones are roughly equal in length, width, and thickness. Examples include the bones in the wrist (carpals) and ankle (tarsals).

Answer 160

These bones are flat and often provide protection and serve as attachment points for muscles. Examples include the skull bones (such as the parietal bone), scapula, and sternum.

Answer 161

These bones have complex shapes that don't fit into the other categories. Examples include the vertebrae and facial bones.

Answer 162

Protects, Supports, and Permits Movement * Provides support for soft organs * Protects many organs * Joints provide flexible movement of many parts of the body

Answer 163

made up of the 80 bones within the central core of your bod * includes the skull, vertebral column (spine), and ribcage * Axial Skeleton Forms the Midline of the Body * Skull * Cranial bones * Facial bones * Axial Skeleton: Vertebral Column

Answer 164

— comprised of the upper and lower extremities, which include the shoulder girdle and pelvis * Includes the bones of the limbs (arms and legs) and the girdles that attach them to the axial skeleton. * Appendicular Skeleton * Includes body parts that attach to axial skeleton * These are referred to as appendages * Appendicular skeleton includes: * Arms, hands, and pectoral girdle * Legs, feet, and pelvic girdle

Answer 165

– Also called the backbone or spine – Protects spinal cord – Column of 33 irregular bones in the following regions:  Cervical (neck): 7 vertebrae  Thoracic (chest): 12 vertebrae  Lumbar (small of the back): 5 vertebrae  Sacral (sacrum): 5 fused vertebrae  Coccygeal (coccyx): 4 fused vertebrae – Intervertebral disks: cushion vertebrae; assist in movement and flexibility

Answer 166

– Also referred to as a “slipped disk” – Sudden movement or impact may cause intervertebral disks to balloon outward compressing spinal nerves – Disk may rupture – Surgical repair may reduce flexibility * Injury to vertebral column may damage or sever spinal cord – May result in complete or partial paralysis

Answer 167

Protecting the Chest Cavity Ribs protect lungs and heart – 12 pair * 10 pair are attached to vertebrae in back, sternum in front * Lowest two pair are “floating,” attached to vertebrae but Not attached to sternum

Answer 168

Lends Flexibility to the Upper Limbs * Permits a wide range of motion * Connected to rest of body by muscles and tendons * Can rotate upper arms almost 360 degrees * Elbows bend and rotate, wrist and fingers can bend and rotate * Opposable thumbs enable grasping and manipulating objects * Susceptible to injury – Dislocated shoulder – Broken clavicle: one of the most common fractures – Repetitive stress: carpal tunnel syndrome

Answer 169

– Supports weight of upper body – Protects organs in pelvic cavity – Attachment of legs * Remodeling of the pelvic girdle in females is triggered by hormones at puberty * Pelvic girdle in women * Broader * Shallower * Wider opening * These changes adapt pelvis for pregnancy and birth

Answer 170

* Sprains – Stretched or torn ligaments – Heal slowly (few cells and poor blood supply) * Bursitis and tendinitis – Inflammation of bursae or tendons * Osteoporosis: excessive bone loss * Arthritis: inflammation of joints – Osteoarthritis – Rheumatoid arthritis

Answer 171

Mature bone cell

Answer 172

- Consists of: heart (pump), blood vessels and blood - Picks up nutrients from digestive system - Distributes nutrients throughout the body - Exchanges gases with respiratory system o Delivers O2 to every cell o Carries CO2 to lungs for removal - Carries wastes and excess water to urinary system - Carries metabolic wastes to liver for removal - Helps regulate body temperature - Contains specialized defensive cells of the immune system

Answer 173

- Blood is a specialized connective tissue: o Formed elements: specialized cells and cell fragments o Liquid component: Plasma - Volume of blood in the body o Adult male: 5-6 L o Adult female: 4-5 L - Blood is five times more viscous than water

Answer 174

- Plasma (makes up 55% of whole blood) o Water o Electrolytes (ions) o Proteins (albumins, globulins, clotting proteins) o Hormones o Gases o Nutrients and Waste - Plasma: liquid portion of the blood - 90% water - 10% dissolved solutes o Proteins o Hormones o Ions o Amino acids o Carbohydrates o Vitamins o Metabolic wastes

Answer 175

- Formed elements (makes up 45% of whole blood) o Red Blood Cells o White Blood Cells o Platelets

Answer 176

- Erythrocytes (red blood cells): 5 million/mm3 - Functions: transport O2 and CO2 - Lack a nucleus and other organelles - Packed with hemoglobin, which transports O2 - Hemoglobin molecule includes four polypeptide chains and four heme groups that each have iron atoms to O2 - Origin: stem cells in the bone marrow - Life span: 120 days in humans

Answer 177

- Factors affecting binding of hemoglobin o concentration: higher O2 promotes binding  Lungs: O2 is high, O2 binds readily to hemoglobin  Tissues: O2 is low, hemoglobin releases O2 to tissues - Hemoglobin measurement o Men: 14–18 gm% Women: 12–14 gm%

Answer 178

- Hematocrit: the percentage of whole blood that consists of red blood cells o Men: 43–49% Women: 37–43% - Low hematocrit or hemoglobin may indicate anemia - High hematocrit may be a response to high elevation. Less O2 available in atmosphere – body adapts by making more red blood cells - Very high hematocrit is risky because of increased blood viscosity.

Answer 179

- Stem cells in bone marrow divide continually throughout the life of an individual. - These stem cells produce all of the types of blood cells. - Stem cells that divide and produce blood cells are called hematopoietic stem cells.

Answer 180

Immature red blood cells - Erythroblasts transform into erythrocytes in the bone marrow prior to release into the blood. - Erythroblasts fill with hemoglobin, mature into red blood cells, and discard their nucleus and organelles.

Answer 181

Mature Red Blood Cells Lack nucleus - Aged RBCs are removed by macrophages (large phagocytic cells) in the liver and spleen. - Iron and amino acids from hemoglobin are recycled. - Heme (minus the iron), is converted to bilirubin, discarded through digestive tract.

Answer 182

aka Leukocytes - Produced by division of stem cells in bone marrow - Functions o Protect against infection o Regulate the inflammatory reaction - Two major categories o Granular: neutrophils, eosinophils, and basophils o Agranular: lymphocytes and monocytes - Most WBCs have a relatively short life span 1-20 days - Circulating levels can rise quickly in response to infection - May leave the blood for the interstitial fluid or lymph

Answer 183

- Megakaryocytes arise from division of stem cells in bone marrow. - Megakaryocytes in bone marrow break into fragments called platelets. - Platelets play an important role in hemostasis. o If blood vessel is injured, platelets initiate the clotting process. o Platelets participate in the repair process.

Answer 184

Stopping Blood Loss 1. Vascular spasm: constriction of blood vessels to reduce blood flow 2. Platelet plug formation: sealing of the ruptured blood vessel 3. Coagulation: formation of a blood clot  Blood changes from a liquid to a gel  Complex series of reactions involving at least 12 different clotting proteins in the plasma

Answer 185

- Bleeding disorder o Hemophilia: deficiency of one or more clotting proteins - Some medications interfere with hemostasis o Aspirin: blocks platelet clumping o Ibuprofen and naproxen may have a similar effect

Answer 186

- Blood transfusion: administration of blood directly into bloodstream of another person - Success depends on matching the blood type of the donor with that of the recipient - What are the different blood types? o ABO Blood Types (A, B, AB, O) o Rh (Rh-Positive) (Rh-Negative) o 8 different blood types

Answer 187

A defensive protein made by the body - May be on a cell from another individual or on the cell of an invading microorganism - Red blood cells from another person may have proteins on their surface (antigens) which are different than the molecules on our red blood cell surfaces - If we receive a blood donation with blood that has these different antigens, our immune system may produce a serious potentially fatal transfusion reaction - The antigen on the R B C surface determines the blood type o Individuals have A and/or B or neither antigen on their red blood cell surfaces (A, B, A B, or O) - Individuals have antibodies against the antigens N O T on their own red blood cells

Answer 188

- Antibodies are gamma globulins, proteins found in the plasma - Many antibodies are directed against infectious microbes - Other antibodies may be directed against other antigens, such as those found on the cells of blood received in a blood transfusion - Antibodies may clump and inactivate antigen-bearing cells

Answer 189

Individual with Type A blood (has anti-B antibodies) can receive A or O Individual with Type B blood (has anti-A antibodies) can receive B or O Individual with Type A B blood (has neither antibody type) can receive AB, A, B, O Individual with Type O blood (has both anti-A and anti-B antibodies) can receive O  Can donate to A, B, AB

Answer 190

another antigen found on red blood cell surfaces - 85% of Americans are R h-positive (have the antigen) - 15% are R h-negative o These individuals will respond to R h-positive blood by producing anti-R h antibodies - Can be a problem when an R h-negative woman is pregnant with an R h-positive fetus. - Mother may produce anti-R h antibodies that cross placenta and damage fetal red blood cells. - Anti-R h antibodies from an R h negative mother may cause hemolytic disease of the newborn in the R h-positive baby. - Risk is much higher for second and subsequent pregnancies. - Can be prevented by giving mother R h o-G A M (anti-R h antibodies) during pregnancy and at delivery

Answer 191

o Transport blood away from the heart o Transport blood under high pressure o Are thick-walled

Answer 192

o Store blood and return it to the heart o Are thin-walled  Blood flows through venules and veins to the heart * Serve as blood volume reservoir * One-way valves permit only one-way blood flow

Answer 193

o Exchange solutes and water with cells of the body o Are microscopic Where Blood Exchanges Substances with Tissues * Structure o Smallest blood vessels, microscopic o Thin-walled: one cell layer thick o Porous

Answer 194

Smallest Arteries

Answer 195

Control blood flow from arterioles into capillaries

Answer 196

 Relaxation of vascular smooth muscle  Increases blood flow to capillaries

Answer 197

 Contraction of vascular smooth muscle  Decreases blood flow to capillaries

Answer 198

extensive networks of capillaries * Function: selective exchange of substances with the interstitial fluid o Beginning of capillary bed, fluid is filtered out of capillary to interstitial fluid, including oxygen, nutrients; urea and diffuse from cells back into the blood Driven by blood pressure * Later in capillary bed, most fluid is reabsorbed by diffusion o Driven by presence of protein in plasma but not in the interstitial fluid

Answer 199

* Pump composed entirely of living cells and cellular materials * Output can vary from 5 liters to 25 liters of blood/minute * Heart rate at rest: 75 beats/minute * Heart rate can accelerate to over 200 beats/minute with exertion * Heart can beat on its own, yet heart rate can be modified by the nervous system

Answer 200

Fibrous Sac that surrounds the heart o Protects and anchors the heart

Answer 201

outermost thin layer of epithelial and connective tissue External Layer

Answer 202

Thick layer of cardiac muscle (sandwiched by the epicardium and endocardium)  Electrical signals flow directly from cell to cell  This layer contracts when the heart beats Middle Layer

Answer 203

Innermost thin layer of endothelial tissue  Continuous with lining of blood vessels INNer layer

Answer 204

* Four chambers o Two atria: upper chambers o Two ventricles: lower chambers o Septum: muscular partition separating right and left sides of the heart

Answer 205

prevent backflow o Two atrioventricular (AV) valves  Tricuspid valve (right side)  Bicuspid (mitral) valve (left side) o Two semilunar valves  Pulmonary valve  Aortic valve

Answer 206

 Lungs  Blood picks up O2 gets rid of CO2 1. Deoxygenated blood from the body travels through the vena cava to the right atrium of the heart. 2. Through the right A V valve into the right ventricle 3. Through the pulmonary semilunar valve into the pulmonary trunk, which divides into the right and left pulmonary arteries and travels to right and left lungs 4. Blood is oxygenated and CO2 is given up within pulmonary capillaries 5. Oxygenated blood travels through the pulmonary veins back to the heart, entering the left atrium

Answer 207

 Rest of body  O2 is delivered, CO2 waste is picked up 1. Oxygenated blood flows from left atrium through left A V valve into left ventricle 2. Oxygenated blood continues from the left ventricle through the aortic semilunar valve into the aorta 3. Through branching arteries and arterioles to tissues 4. Through the arterioles to capillaries 5. Within capillaries, nutrients and oxygen are delivered and wastes are picked up 6. From capillaries into venules and veins 7. To the vena cava and into the right atrium

Answer 208

(0.1 second) o Both atria contract o A V valves open, semilunar valves are closed o Ventricles fill

Answer 209

(0.3 second) o Both ventricles contract o A V valves close, semilunar valves open o Blood is pushed into pulmonary trunk and aorta

Answer 210

(0.4 second) o Both atria and ventricles relax o Semilunar valves close

Answer 211

closing of both A V valves during ventricular systole

Answer 212

closing of both semilunar valves during ventricular diastole

Answer 213

small mass of cardiac cells in upper right atrium o Cardiac pacemaker o Initiates the heartbeat spontaneously o Pace can be modified by nervous system * Atrioventricular (A V) node o Located between atria and ventricles o Relays impulse

Answer 214

* A record of the electrical impulses in the cardiac conduction system * ECG involves placing electrodes on the skin at the chests, wrists, and ankles. The electrodes transmit the hearts electrical impulses, which are recorded as a continuous line on a screen or moving graph. * E K G s can detect o Arrhythmias o Ventricular fibrillation (rapid irregular ventricular contraction)

Answer 215

* The blood exerts force on the wall of the blood vessels * Blood pressure is highest in arteries, much less in capillaries, lowest in veins * Sphygmomanometer device used to measure blood pressure o Inflatable cuff is positioned over the brachial artery o Gauge or digital screen reports the pressure * Units: m m H g (millimeters of mercury)

Answer 216

highest pressure, as blood is ejected during ventricular systole high point of pressure during cardiac cycle o Systolic pressure <120 m m H g

Answer 217

lowest pressure, as blood returns to the heart during ventricular diastole low point of pressure during cardiac cycle o Diastolic pressure <80 m m H g

Answer 218

High Blood Pressure Can Be Dangerous * Sustained elevation in blood pressure o Systolic pressure ≥ 140 mm Hg o Diastolic pressure ≥ 90 mm Hg * Risk factor for cardiovascular disease o Higher blood pressure causes greater strain on cardiovascular system o Blood vessels react by becoming hardened and scarred o Strain on heart from having to work harder

Answer 219

When Blood Pressure Is Too Low * Low blood pressure * If low enough, may cause dizziness or fainting * May follow abrupt changes in body position o Standing up suddenly * May result from excessive blood loss or fluid loss from burns

Answer 220

* If blood flow to an area of the heart is impaired long enough – sudden death of an area of heart tissue due to oxygen starvation * Sudden death of the affected myocardium * Symptoms o Intense chest pain, sense of tightness or pressure on the chest that makes it hard to breath, and pain radiated down the left arm. Women tend to experience nausea and jaw and back pain. * Requires immediate medical attention * Treatment and/or prevention o Control of arrhythmias o Clot-dissolving medications o Coronary artery bypass graft (C A B G)—vein from leg is grafted in order to bypass obstructed coronary artery

Answer 221

weakness of heart causes fluid back-up in interstitial spaces o Out of breath, swollen ankles, legs, neck veins * Why does the heart weaken? o Age, prior heart attacks, leaky heart valves, lung disease, uncontrolled hypertension * Treatment o Improve cardiac performance, efficiency o Prevent accumulation of interstitial fluid o Medications:  Diuretics: remove excess fluids  Medications to cause heart to beat more forcefully

Answer 222

* A sudden blockage of a blood vessel by material floating in the bloodstream * Often a blood clot breaks away from a larger clot elsewhere * May be cholesterol deposits, tissue fragments, cancer cells, clumps of bacteria, bubbles of air * Locations o Pulmonary embolism—chest pain, shortness of breath o Cerebral embolism—may cause a stroke o Cardiac embolism—may cause a heart attack

Answer 223

* Damage to part of brain caused by an interruption in blood supply * Two common causes o Embolism blocking a vessel o Rupture of a cerebral artery * Symptoms: depend on area of brain affected * Immediate medical care is crucial o If embolism, patient receives clot-dissolving drugs o If rupture, surgical repair is sometimes possible * Recovery may require extensive rehabilitation

Answer 224

A subset of these microorganisms and viruses that cause disease o Cancer cells

Answer 225

o Extremely small, much smaller than bacteria o Living? .....  Open to debate  Unable to reproduce outside of a host cell  No metabolic activity o Structure  Contain D N A or R N A, not both  Nucleic acid is surrounded by a protein coat (capsid) o Diseases caused by viruses include  AIDS, COVID-19, hepatitis, encephalitis, rabies, influenza, colds, warts, chicken pox, Ebola hemorrhagic fever

Answer 226

large outbreak of infectious disease in a particular community, population, or region

Answer 227

epidemic that spreads to many countries or worldwide * Example: COVID-19

Answer 228

 1. Maintenance of blood volume in cardiovascular system  2. Filtration of foreign material to defend against infection

Answer 229

o Network of vessels, similar in structure to veins  Drain into cardiovascular system through right lymphatic duct and thoracic duct o Lymph is a milky fluid containing  White blood cells  Proteins  Fats  Occasionally bacteria and viruses

Answer 230

o Lymph nodes are located at intervals along lymphatic vessels o Nodes remove microorganisms, debris, and abnormal cells from lymph o Small, 1 m m to 2.5 m m in size o Nodes are composed of connective tissue, macrophages, and lymphoctyes o Nodes act as filters

Answer 231

o Largest lymphatic organ o Located in upper left abdominal cavity o Two regions of spleen  Red pulp * Removes old and damaged red blood cells * Temporary blood storage  White pulp * Contains lymphocytes, searching for pathogens o Diseases that cause spleen enlargement  Infectious mononucleosis, leukemia o Spleen can be removed with minor medical impact

Answer 232

 Located behind sternum, above heart  Site of maturation of T cells (T lymphocytes)  Largest, most active during childhood  Atrophies with age

Answer 233

 Masses of lymphatic tissue near the entrance to the throat  Filter food and air entering the throat  Sometimes become infected: tonsilitis

Answer 234

 Lymphatic tissue near back of nasal passages  Filter air

Answer 235

 Skin—an effective deterrent  Tears and saliva—contain lysozyme (antibacterial enzyme)  Ear wax—entraps microorganisms  Mucus—entraps microorganisms  Coughing, sneezing  Stomach—highly acidic, inhibits microorganisms  Vomiting, urination, and defecation—remove microorganisms

Answer 236

dietary supplements that contain living microorganisms, intentionally consumed to establish or restore beneficial microbiota

Answer 237

dietary supplements or foods that are consumed to encourage the growth of beneficial microbes in the gut

Answer 238

o Varied group of defenses that attack pathogens that have breeched the physical and chemical barriers of the first line of defense o Include:  Complement proteins  Phagocytic cells  Inflammation  Natural killer cells

Answer 239

o Includes at least 30 proteins that circulate in the blood in an inactive state * When activated by invading microorganisms, the activated complement proteins defend by: o Creating holes in the invading microorganisms o Enhancing inflammation, which attracts phagocytes o Directly lysing invading microorganisms

Answer 240

o Phagocytes are white blood cells that engulf and digest foreign cells through the process of phagocytosis o Some phagocytes are constantly on the move seeking out invaders; others take up residence in lymph nodes, spleen, lungs, other tissues

Answer 241

* “first reponders” * Initiate inflammatory cascade * Self destruct after eating microorganisms (pus)

Answer 242

Form monocytes that leave the vascular system and enter tissue fluids * Can be fixed or free in the body * Can eat microorganisms over and over

Answer 243

* Inflammation: Redness, Warmth, Swelling, Pain - triggered by tissue injury o Signs: Redness, Warmth, Swelling, Pain o Purpose: dispose of cellular debris and pathogens, and initiate tissue repair o Process:  Injured cells release histamine and other inflammatory mediators  Inflammatory mediators cause increased blood flow to the area and attract phagocytic cells  Phagocytic cells engulf invading microbes and clean up debris  Repair mechanisms are initiated o Mass cells: in connective tissues

Answer 244

are a type of lymphocytes o Able to recognize:  Virus-infected host cells  Tumor (cancer) cells (they can kill your own cells that become cancerous) o Contact their target cells:  Make a hole in the target cell membrane or can engulf them  Release enzymes into the target cell to destroy it

Answer 245

substances that produce a fever o Pyrogens cause the brain to reset the body’s thermostat at a higher temperature o Fever’s defensive properties:  Makes the body less hospitable to pathogens  Enhance body’s defenses

Answer 246

 The immune response  Characteristics: * Recognizes and targets specific pathogens and foreign substances * Has “memory”—“remembers” initial exposure and responds more quickly and aggressively on subsequent exposures  Able to distinguish between: * “Self” cells and foreign, “nonself” invaders * Healthy cells and abnormal (tumor) cells

Answer 247

foreign substance that triggers an immune response  Usually protein or polysaccharide * Often on outer surface of an invading bacteria or virus  M H C (major histocompatibility complex) proteins * Self-antigens that are on human cell surfaces, enabling recognition of “self” * Enable immune system to distinguish “self” from “nonself” * Your body recognizes these as uniquely “you” but they would appear foreign (antigenic) to someone else’s immune system

Answer 248

a type of white blood cell, originating from stem cells in the bone marrow

Answer 249

Antibody-mediated immunity

Answer 250

proteins made by descendants of B lymphocytes that bind with specific antigens * Have after first infection  Active against viruses, bacteria, and soluble foreign molecules  Identify microorganisms  B memory cells remember these organisms  Tag the specific microorganism, can have multiple antibodies on the same organism * Can clump multiple of the microorganisms together “big blob”  Circulate in blood and lymph, also found in mucous secretions and breast milk  Bind to the specific antigen that triggered their production forming antigen-antibody complexes * May cause agglutination (clumping) of antigens * May “tag” the antigen and promote its recognition and removal by phagocytic cells * May activate complement, which then lyses the antigen-bearing cell * May neutralize viruses, bacteria, and toxins by blocking their ability to bond to host cell receptors

Answer 251

Cell-mediated immunity  Directly attack foreign cells or infected “self” cells  Active against cancer cells, cells with “nonself” M H C  Responsible for cells, typically tumor causing or cancer causing “cells gone rogue”

Answer 252

 Originate from stem cells in the bone marrow  Mature in the thymus o T-cells located in the plasma

Answer 253

 Secrete cytokines, which stimulate other immune system cells  Play a key role in directing the immune response  Are targets of H I V infection

Answer 254

 Directly attack and destroy abnormal (tumor or viral-infected) cells and foreign cells  Host cells that are cancerous (tumor cells)  Transplanted organs or tissue (if not appropriately matched) o Cytotoxic T cell binds to target cell o Cytotoxic T cell secretes two proteins which together destroy the target cell  Perforin: forms a pore in the target cell plasma membrane * Perforin pokes a hole in the target cell o Granzyme: enters the pore and digests and kills the target cell

Answer 255

 Reactivate during later exposures  Protects against future infections  Remembers infections from before so can protect better in the future

Answer 256

 Occurs on first exposure to antigen  Characteristics: * Lag time (delay) of 3-6 days for antibody production * Antibody production peaks at 10-12 day

Answer 257

 Occurs on second or subsequent exposures to antigen * Minimal lag time (hours) * Antibody level (titer) rises much more quickly * Much more antibody is produced * Antibody levels stay elevated longer  Due to long-lived memory cells produced during primary response

Answer 258

* Intentionally expose individual to a form of the antigen that doesn’t produce disease (vaccine) – weakened or dead * Also known as vaccination * Vaccine may be: o Killed or inactivated pathogen o Attenuated (weakened) pathogen o Some part or component of the pathogen (subunit) o Piece of nucleic acid (D N A or R N A) that encodes an antigen from a pathogen * Recipient will develop a primary immune response including memory cells * Recipient is now primed for a strong secondary response when exposed to the pathogen in the future

Answer 259

* No vaccines * Administer protective antibodies to an individual from a doner

Answer 260

o Antibiotics kill bacteria or inhibit their growth  Antibiotics are selectively toxic for bacteria by targeting features of bacterial cells that are different from eukaryotic cells * Example: penicillin inhibits bacterial cell wall synthesis  Narrow spectrum antibiotics: effective against a small group of bacteria  Broad spectrum antibiotics: effective against a wider variety of bacteria * May have negative impact on normal microbiota  Antibiotics are not effective against viruses

Answer 261

hypersensitivity reactions  Inappropriate response to an allergen  Allergen: any substance (antigen) that causes an allergic reaction (not a pathogen, but the body reacts as though it is a pathogen)  Examples of allergens * Pollen * Mold spores * Dust mites o Treatment of allergies  Antihistamines – treatment of mild to moderate reactions  Epinephrine injection – treatment of anaphylactic shock  Allergy shots

Midterm Study Deck Flashcards

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