Final Review Sheet Flashcards
0
Q
What are the Properties of Living Things?
A
- Organization - exhibit a higher level of organization than non-living organisms
- Cellular Composition - compartmentalized into one or more cells
- Metabolism - the sum of all internal chemical change
- Responsiveness and Movement - the ability of an organism to sense and react to stimuli
- Homeostasis - maintain internal stability
- Development - any change in form or function over the lifetime of the organism
- Reproduction - produces copies of themselves
1
Q
What is the Hierarchy of Complexity?
A
- Organism - a single complete individual
- Organ System - a group of organs with a unique collective function
- Organ - two or more tissues that work together to carry out a function
- Tissue - a mass of similar cells and cell products that form a discrete region of an organ and performs a specific function
- Cell - the smallest unit of an organism that carries out all the basic functions of life
- Organelle - structure in a cell that carries out its individual functions
- Molecule - a particle of composed atoms
- Atom - the smallest particle with unique chemical identities
2
Q
What are the types of metabolism?
A
a. Anabolism - molecules are synthesized
b. Catabolism - molecules are broken down
c. Excretion - the separation of wastes from the tissues and their elimination from the body
3
Q
What is responsiveness and movement?
A
a. Nerve and muscle cells
b. Self-propelled movement from place to place
4
Q
What are the different types of development?
A
a. Differentiation - the transformation of cells with no specialized function into cells that are committed to a particular task
b. Growth - an increase in size
5
Q
What are Chemical Bonds?
A
Forces that hold a molecule together and attract molecules to one another
6
Q
What are the types of Chemical Bonds?
A
a. Ionic Bond - weak attraction of a cation to an anion that easily dissociates in the presence of something more attractive
b. Covalent Bonds - attraction between atoms formed by the sharing of electrons
c. Hydrogen Bond - a weak attraction between a hydrogen atom in a molecule and an oxygen or nitrogen in another
d. Van der Waals forces - weak, brief attractions between neutral atoms
7
Q
What are the types of covalent bonds?
A
i. ) Single Covalent Bond - sharing of a single pair of electrons
ii. ) Double Covalent Bond - sharing of two pairs of electrons
8
Q
What is the physiology of water?
A
- Most mixtures in our bodies are chemicals dissolved in H2O
- Water is a very cohesive liquid because of its hydrogen bonds
9
Q
What are the characteristics of water?
A
- Solvency - the ability to dissolve other chemicals
- Adhesion - the tendency of one substance to cling to another
- Cohesion - the tendency of molecules of the same substance to cling to each other
- Chemical Reactivity - water participates in chemical reactions by ionizing other chemicals
- Thermal Stability - water has a high heat capacity and thus can absorb heat without changing temperature much
10
Q
What are the types of solvency?
A
a. Hydrophilic - substances that dissolve in water
b. Hydrophobic - substances that do not dissolve in water
11
Q
What is the physiology of adhesion?
A
Water adheres to the body’s tissue and forms a lubricating film
12
Q
What is the physiology of cohesion?
A
a. Water is a cohesive liquid because of its hydrogen bonds
b. Surface tension - a force that holds water molecules together so that they form an elastic layer
13
Q
What are Carbohydrates and their different types?
A
- Carbohydrate - hydrophilic organic molecule with the general formula (CH2O)n, where n represents the number of carbon atoms
- Simplest carbohydrates are monomers called monosaccharides
- Disaccharides - sugars composed of two monosaccharides
- Oligosaccharides - short chains of three or more monosaccharides
- Polysaccharides - long chains of monosaccharides
14
Q
What are the three primary carbohydrates?
A
- The three primary are glucose, fructose, and galactose all are C6H12O6
- Glucose is the “blood sugar” that provides energy for most cells
15
Q
What are the primary polysaccharides?
A
a. Glycogen - energy-storage molecule made by cells of the liver, muscles, brain, uterus, and vagina
b. Starch - energy-storage molecule of plants that is digestible by humans
c. Cellulose - molecule that gives strength to the cell walls of plants, not digestible by humans but is important as a dietary fiber
16
Q
What are the functions of carbohydrates?
A
a. A source of energy that can be quickly mobilized
b. Carbohydrates are converted to glucose, which is oxidized to make ATP
c. Glycolipids - component of cell surface coat
d. Glycoproteins - component of cell surface coat and mucus
e. Proteoglycans - cell adhesion, lubrication, and filler of some tissues
17
Q
What are lipids?
A
A lipid is a hydrophobic organic molecule with a high ratio of H to O
18
Q
What are the different types of lipids?
A
- Fatty Acid - a chain of carbon atoms with a -COOH at one end and -CH3 on the other
- Triglyceride - a molecule consisting of three fatty acids bonded to glycerol
- Phospholipids - similar to triglycerides except one fatty acid is replaced by a phosphate group
- Eicosanoids - 20-carbon compounds derived from a fatty acid
- Cholesterol - a lipid with carbons arranged in four rings
19
Q
What are the types of Fatty Acids?
A
a. Saturated Fatty Acid -
b. Unsaturated Fatty Acid - contains some double bonds so hydrogen could be added to the molecule
20
Q
What are the types of Triglycerides?
A
a. Oils - triglycerides that are liquid at room temperature
b. Saturated Fats - solid at room or body temperature
c. Adipose Tissue - energy-storage, insulation and cushions organs
21
Q
What is the physiology of Phospholipids?
A
a. The fatty acids are hydrophobic, but the phosphate is hydrophilic
b. Phospholipids serve as the foundation of cell membranes
22
Q
What are the physiology of Eicosanoids?
A
a. Function as hormone-like chemical signals between cells
b. Prostaglandins - play a variety of signaling roles in inflammation, blood clotting, hormone action, labor contractions, etc
23
Q
What is the physiology of Cholesterol?
A
a. Cholesterol - the “parent” from which steroids are formed
b. Cholesterol is also a component of cell membranes and is required for nervous system functions
c. Steroids - hormones
24
What are the Functions of Membrane Proteins?
a. Receptors - surface proteins where chemical signals from other cells bind chemicals and transport them into the cell
b. Second-Messenger System - a chemical messenger binds to an EC receptor triggering an IC peripheral protein to relay the message to an enzyme which converts a molecule to a second messenger
c. Enzymes - digest nutrients, help produce second messengers, and breakdown signaling molecules
d. Channel Proteins - passageways that allow water and hydrophilic solutes to move through the membrane
e. Carriers - transmembrane proteins that transfer solutes to the other side of the membrane
f. Cell-Identity Markers - glycoprotein acting as "identification tags"
g. Cell-Adhesion Molecules - membrane proteins that bind one cell to another or to extracellular material
25
What are the differences between Simple Diffusion?
1. Simple Diffusion - the movement of particles from a place of high diffusion to a place of lower concentration
2. Concentration Gradient - the concentration of a substance differs from one point to another
26
What are the types of Concentration Gradients?
a. Down or With the Gradient - particle move from a region of high concentration to a region of lower concentration
b. Up or Against the Gradient - particles move from a region of low concentration to a region of higher concentration
27
What are the factors that affect the rate of diffusion?
a. Temperature - the warmer a substance is, the more rapidly its particles diffuse
b. Molecular Weight - heavy molecules diffuse more slowly than light
c. Steepness of concentration gradient
d. Membrane Surface Area - more surface area means more diffusion
e. Membrane Permeability - nonpolar, hydrophobic, lipid-soluble substances diffuse through phospholipids
28
What are the mechanisms of carrier-mediated transport?
a. Facilitated Diffusion - transport of a solute through the membrane, down its concentration gradient
b. Primary Active Transport - transport of a solute through the membrane, up its concentration gradient using ATP
c. Secondary Active Transport - transport that requires energy input, but depends only indirectly on ATP
29
What are the different parts of organelles?
1. Organelles - structures in a cell that carry out specialized metabolic tasks
2. The Nucleus - the largest organelle, it contains the cell's chromosomes and is the genetic control center of the cell
3. Endoplasmic Reticulum (ER) - interconnected channels
4. Ribosomes - small granules of proteins and RNA, they interpret the genetic code and synthesize polypeptides
5. Golgi Complex
6. Lysosomes - a package of enzymes used for IC digestion and autophagy
7. Peroxisomes - a package of enzymes that use O2 for detoxification and breaking down fatty acid which produces hydrogen peroxide
8. Mitochondria - a double membrane organelle that synthesizes ATP
9. Centriole - a short assembly of microtubules that play a role in cell division and also form the basal body of a flagellum or cilium
30
What makes up the nucleus?
a. Nuclear envelope - two membranes surrounding the nucleus
b. Nuclear pores - proteins that perforate the envelope, regulate traffic through the envelope and hold the membrane together
c. Chromatin - fine thread-like matter composed of DNA and protein
d. Nucleoli - masses where ribosomes are produced
31
What are the types of Endoplasmic Reticulum (ER)?
a. Rough ER - flattened sacs covered with ribosomes, where phospholipids and proteins are produced
b. Smooth ER - tubular channels with no ribosomes, where detoxification occurs, steroid hormones are synthesized, and calcium is stored for muscle contraction
32
What is the Golgi Complex?
a. System of channels that synthesize carbohydrates and finish up protein and glycoprotein synthesis
b. Vesicles bud off the Golgi and become lysosomes, add new proteins and phospholipids to the membrane, or become secretory vesicles
33
What is DNA?
DNA is a polymer of nucleotides
34
What makes up DNA?
a. Nucleotides consist of a sugar, phosphate group, and nitrogenous base
b. Nitrogenous bases are cytosine (C), thymine (T), and guanine (G)
35
What is the structure of DNA?
DNA is described as a double helix that resembles a spiral staircase
a. Each side is composed of phosphate groups alternating with deoxyribose (sugar)
b. The step-like connections are pairs of nitrogenous bases (A-T, G-C) which hold the side pieces together with hydrogen bonds
36
What is the primary function of DNA?
The essential function is to carry instructions for synthesis of proteins
37
What is the structure of RNA?
1. RNA consists only of one nucleotide chain
2. The sugar is ribose
3. RNA has no thymine, but uracil takes its place
38
What are the types of RNA?
a. mRNA - the molecule that carries the genetic code from the nucleus to the cytoplasm
b. tRNA - binds a free amino acid and delivers it to the ribosome
c. Ribosome - the molecule that "reads" the mRNA
39
What are the phases of mitosis?
a. Prophase
b. Metaphase - the chromosomes align at the cell equator
c. Anaphase - sister chromatids are pulled apart to opposite poles of the cell
d. Telophase
40
What happens during prophase?
i. ) Chromosomes coil into compact rods which consist of two identical sister chromatids
ii. ) The nuclear envelope disintegrates
41
What happens during telophase?
i. ) A new nuclear envelope forms around the chromatids
| ii. ) The chromatids uncoil
42
What is simple epithelia?
Only one layer of cells
43
What are the types of simple epithelia?
1. Simple Squamous Epithelium - thin cells with flattened nucleus
2. Simple Cuboidal Epithelium - square or round cells
3. Simple Columnar Epithelium - tall, narrow cells
4. Pseudostratified Columnar Epithelium - looks multilayered, some cells do not reach the free surface, often with goblet cells and cilia
44
What are the locations and functions of simple squamous epithelium?
a. Locations - alveoli, glomerlular capsule, endothelium, serosa
b. Functions - allows rapid diffusion or transport of substances through membranes, secretes lubricating serous fluid
45
What are the locations and functions of simple cuboidal epithelium?
a. Locations - liver, thyroid, mammary, salivary, and other glands; most kidney tubules, bronchioles
b. Functions - absorption and secretion, mucus production, movement of respiratory mucus
46
What are the locations and functions of simple columnar epithelium?
a. Locations - inner lining of the stomach, intestines, gall bladder, uterus, uterine tubes; some kidney tubules
b. Functions - absorption, secretion of mucus, movement of egg and embryo
47
What are the locations and functions of pseudostratified columnar epithelium?
a. Locations - respiratory tract from nasal cavity to bronchi
b. Functions - secretes and propels mucus
48
What are the types of fibrous connective tissue?
1. Areolar tissue - loose network of collagen and elastic fibers and cells
2. Reticular tissue - loose network of reticular fibers and cells
3. Dense regular CT - densely packed, parallel collagen fibers
4. Dense irregular CT - densely packed collagen fibers in random directions
49
What are the locations and functions of areolar tissues?
a. Locations - under epithelia; around BV, nerve esophagus, trachea
b. Functions - binds epithelia to deeper tissues; allows passage of nerves and BV through tissues
50
What are the locations and functions of reticular tissue?
a. Locations - lymph nodes, spleen, thymus, bone marrow
| b. Functions - supportive framework for lymphatic organs
51
What are the locations and functions of dense regular CT?
a. Locations - tendon and ligament
| b. Functions - ligaments bind bone to bone; tendon binds muscle to bone
52
What are the locations and functions of dense irregular CT?
a. Locations - deeper part of dermis; capsules a rounds organs such as liver, kidney, spleen; fibrous sheaths around cartilage and bone
b. Functions - durable, hard to tear
53
What are the cell junctions?
1. Cell junction - the connections between one cell junction and another
2. Tight junctions - proteins that encircle an epithelial cell near its apex and join to proteins of nearby cells thus sealing of the intercellular space
3. Desmosomes - a patch-like intercellular junction that mechanically links two cells together to keep the cells from pulling apart
4. Hemidesmosomes - junctions on the basal cells of the epithelium then link them to the basement membrane
5. Gap junction - transmembrane proteins surrounding a channel that allows solutes to diffuse from one cell to the next
54
What are the functions of skin?
1. Resistance to trauma and infection
2. Other barrier functions
3. Vitamin D synthesis - carries out the first step, liver and kidneys complete
4. Sensation - contains a variety of nerve endings that react to heat, cold, touch, texture, pressure, vibration, and injury
5. Thermoregulation - thermoreceptors monitor the body surface temperature
55
How does skin resist trauma and infection?
a. Epidermal cells are packed with keratin and linked by desmosomes, giving it durability
b. Skin is dry, slightly acidic and contains antimicrobial peptides
56
What are the other barrier functions of skin?
a. Barrier to water - prevents water gain and water loss
b. Barrier to UV rays which are cancer causing
c. Barrier to harmful chemicals
57
What does thermoregulation do?
a. When chilly - blood vessels of the dermis constrict, keeping warm blood deeper in the body
b. When overheating - blood vessels of the dermis dilate, allowing more blood to flow close to the surface and lose heat through skin
c. Sweat glands secrete sweat and sweat evaporation cools the body
58
What are the cells of the epidermis?
a. Stem cells - undifferentiated cells located in the stratum basale that divide and give rise to the keratinocytes
b. Keratinocytes - the majority of cells, they synthesize keratin
c. Melanocytes - synthesize the dark pigment melanin which is picked up by the keratinocytes to protect DNA from UV radiation
d. Tactile (Merkel) cells - receptors for touch
e. Dendritic cells - defense cells that migrate to the dermis
59
What are Carbohydrates and their different types?
1. Carbohydrate - hydrophilic organic molecule with the general formula (CH2O)n, where n represents the number of carbon atoms
2. Simplest carbohydrates are monomers called monosaccharides
3. Disaccharides - sugars composed of two monosaccharides
4. Oligosaccharides - short chains of three or more monosaccharides
5. Polysaccharides - long chains of monosaccharides
60
What are the three primary carbohydrates?
1. The three primary are glucose, fructose, and galactose all are C6H12O6
2. Glucose is the "blood sugar" that provides energy for most cells
61
What are the primary polysaccharides?
a. Glycogen - energy-storage molecule made by cells of the liver, muscles, brain, uterus, and vagina
b. Starch - energy-storage molecule of plants that is digestible by humans
c. Cellulose - molecule that gives strength to the cell walls of plants, not digestible by humans but is important as a dietary fiber
62
What are the functions of carbohydrates?
a. A source of energy that can be quickly mobilized
b. Carbohydrates are converted to glucose, which is oxidized to make ATP
c. Glycolipids - component of cell surface coat
d. Glycoproteins - component of cell surface coat and mucus
e. Proteoglycans - cell adhesion, lubrication, and filler of some tissues
63
What are lipids?
A lipid is a hydrophobic organic molecule with a high ratio of H to O
64
What are the different types of lipids?
1. Fatty Acid - a chain of carbon atoms with a -COOH at one end and -CH3 on the other
2. Triglyceride - a molecule consisting of three fatty acids bonded to glycerol
3. Phospholipids - similar to triglycerides except one fatty acid is replaced by a phosphate group
4. Eicosanoids - 20-carbon compounds derived from a fatty acid
5. Cholesterol - a lipid with carbons arranged in four rings
65
What are the types of Fatty Acids?
a. Saturated Fatty Acid -
| b. Unsaturated Fatty Acid - contains some double bonds so hydrogen could be added to the molecule
66
What are the types of Triglycerides?
a. Oils - triglycerides that are liquid at room temperature
b. Saturated Fats - solid at room or body temperature
c. Adipose Tissue - energy-storage, insulation and cushions organs
67
What is the physiology of Phospholipids?
a. The fatty acids are hydrophobic, but the phosphate is hydrophilic
b. Phospholipids serve as the foundation of cell membranes
68
What are the physiology of Eicosanoids?
a. Function as hormone-like chemical signals between cells
b. Prostaglandins - play a variety of signaling roles in inflammation, blood clotting, hormone action, labor contractions, etc
69
What is the physiology of Cholesterol?
a. Cholesterol - the "parent" from which steroids are formed
b. Cholesterol is also a component of cell membranes and is required for nervous system functions
c. Steroids - hormones
70
What are the Functions of Membrane Proteins?
a. Receptors - surface proteins where chemical signals from other cells bind chemicals and transport them into the cell
b. Second-Messenger System - a chemical messenger binds to an EC receptor triggering an IC peripheral protein to relay the message to an enzyme which converts a molecule to a second messenger
c. Enzymes - digest nutrients, help produce second messengers, and breakdown signaling molecules
d. Channel Proteins - passageways that allow water and hydrophilic solutes to move through the membrane
e. Carriers - transmembrane proteins that transfer solutes to the other side of the membrane
f. Cell-Identity Markers - glycoprotein acting as "identification tags"
g. Cell-Adhesion Molecules - membrane proteins that bind one cell to another or to extracellular material
71
What are the differences between Simple Diffusion?
1. Simple Diffusion - the movement of particles from a place of high diffusion to a place of lower concentration
2. Concentration Gradient - the concentration of a substance differs from one point to another
72
What are the types of Concentration Gradients?
a. Down or With the Gradient - particle move from a region of high concentration to a region of lower concentration
b. Up or Against the Gradient - particles move from a region of low concentration to a region of higher concentration
73
What are the factors that affect the rate of diffusion?
a. Temperature - the warmer a substance is, the more rapidly its particles diffuse
b. Molecular Weight - heavy molecules diffuse more slowly than light
c. Steepness of concentration gradient
d. Membrane Surface Area - more surface area means more diffusion
e. Membrane Permeability - nonpolar, hydrophobic, lipid-soluble substances diffuse through phospholipids
74
What are the mechanisms of carrier-mediated transport?
a. Facilitated Diffusion - transport of a solute through the membrane, down its concentration gradient
b. Primary Active Transport - transport of a solute through the membrane, up its concentration gradient using ATP
c. Secondary Active Transport - transport that requires energy input, but depends only indirectly on ATP
75
What are the different parts of organelles?
1. Organelles - structures in a cell that carry out specialized metabolic tasks
2. The Nucleus - the largest organelle, it contains the cell's chromosomes and is the genetic control center of the cell
3. Endoplasmic Reticulum (ER) - interconnected channels
4. Ribosomes - small granules of proteins and RNA, they interpret the genetic code and synthesize polypeptides
5. Golgi Complex
6. Lysosomes - a package of enzymes used for IC digestion and autophagy
7. Peroxisomes - a package of enzymes that use O2 for detoxification and breaking down fatty acid which produces hydrogen peroxide
8. Mitochondria - a double membrane organelle that synthesizes ATP
9. Centriole - a short assembly of microtubules that play a role in cell division and also form the basal body of a flagellum or cilium
76
What makes up the nucleus?
a. Nuclear envelope - two membranes surrounding the nucleus
b. Nuclear pores - proteins that perforate the envelope, regulate traffic through the envelope and hold the membrane together
c. Chromatin - fine thread-like matter composed of DNA and protein
d. Nucleoli - masses where ribosomes are produced
77
What are the types of Endoplasmic Reticulum (ER)?
a. Rough ER - flattened sacs covered with ribosomes, where phospholipids and proteins are produced
b. Smooth ER - tubular channels with no ribosomes, where detoxification occurs, steroid hormones are synthesized, and calcium is stored for muscle contraction
78
What is the Golgi Complex?
a. System of channels that synthesize carbohydrates and finish up protein and glycoprotein synthesis
b. Vesicles bud off the Golgi and become lysosomes, add new proteins and phospholipids to the membrane, or become secretory vesicles
79
What is DNA?
DNA is a polymer of nucleotides
80
What makes up DNA?
a. Nucleotides consist of a sugar, phosphate group, and nitrogenous base
b. Nitrogenous bases are cytosine (C), thymine (T), and guanine (G)
81
What is the structure of DNA?
DNA is described as a double helix that resembles a spiral staircase
a. Each side is composed of phosphate groups alternating with deoxyribose (sugar)
b. The step-like connections are pairs of nitrogenous bases (A-T, G-C) which hold the side pieces together with hydrogen bonds
82
What is the primary function of DNA?
The essential function is to carry instructions for synthesis of proteins
83
What is the structure of RNA?
1. RNA consists only of one nucleotide chain
2. The sugar is ribose
3. RNA has no thymine, but uracil takes its place
84
What are the types of RNA?
a. mRNA - the molecule that carries the genetic code from the nucleus to the cytoplasm
b. tRNA - binds a free amino acid and delivers it to the ribosome
c. Ribosome - the molecule that "reads" the mRNA
85
What are the phases of mitosis?
a. Prophase
b. Metaphase - the chromosomes align at the cell equator
c. Anaphase - sister chromatids are pulled apart to opposite poles of the cell
d. Telophase
86
What happens during prophase?
i. ) Chromosomes coil into compact rods which consist of two identical sister chromatids
ii. ) The nuclear envelope disintegrates
87
What happens during telophase?
i. ) A new nuclear envelope forms around the chromatids
| ii. ) The chromatids uncoil
88
What is simple epithelia?
Only one layer of cells
89
What are the types of simple epithelia?
1. Simple Squamous Epithelium - thin cells with flattened nucleus
2. Simple Cuboidal Epithelium - square or round cells
3. Simple Columnar Epithelium - tall, narrow cells
4. Pseudostratified Columnar Epithelium - looks multilayered, some cells do not reach the free surface, often with goblet cells and cilia
90
What are the locations and functions of simple squamous epithelium?
a. Locations - alveoli, glomerlular capsule, endothelium, serosa
b. Functions - allows rapid diffusion or transport of substances through membranes, secretes lubricating serous fluid
91
What are the locations and functions of simple cuboidal epithelium?
a. Locations - liver, thyroid, mammary, salivary, and other glands; most kidney tubules, bronchioles
b. Functions - absorption and secretion, mucus production, movement of respiratory mucus
92
What are the locations and functions of simple columnar epithelium?
a. Locations - inner lining of the stomach, intestines, gall bladder, uterus, uterine tubes; some kidney tubules
b. Functions - absorption, secretion of mucus, movement of egg and embryo
93
What are the locations and functions of pseudostratified columnar epithelium?
a. Locations - respiratory tract from nasal cavity to bronchi
b. Functions - secretes and propels mucus
94
What are the types of fibrous connective tissue?
1. Areolar tissue - loose network of collagen and elastic fibers and cells
2. Reticular tissue - loose network of reticular fibers and cells
3. Dense regular CT - densely packed, parallel collagen fibers
4. Dense irregular CT - densely packed collagen fibers in random directions
95
What are the locations and functions of areolar tissues?
a. Locations - under epithelia; around BV, nerve esophagus, trachea
b. Functions - binds epithelia to deeper tissues; allows passage of nerves and BV through tissues
96
What are the locations and functions of reticular tissue?
a. Locations - lymph nodes, spleen, thymus, bone marrow
| b. Functions - supportive framework for lymphatic organs
97
What are the locations and functions of dense regular CT?
a. Locations - tendon and ligament
| b. Functions - ligaments bind bone to bone; tendon binds muscle to bone
98
What are the locations and functions of dense irregular CT?
a. Locations - deeper part of dermis; capsules a rounds organs such as liver, kidney, spleen; fibrous sheaths around cartilage and bone
b. Functions - durable, hard to tear
99
What are the cell junctions?
1. Cell junction - the connections between one cell junction and another
2. Tight junctions - proteins that encircle an epithelial cell near its apex and join to proteins of nearby cells thus sealing of the intercellular space
3. Desmosomes - a patch-like intercellular junction that mechanically links two cells together to keep the cells from pulling apart
4. Hemidesmosomes - junctions on the basal cells of the epithelium then link them to the basement membrane
5. Gap junction - transmembrane proteins surrounding a channel that allows solutes to diffuse from one cell to the next
100
What are the functions of skin?
1. Resistance to trauma and infection
2. Other barrier functions
3. Vitamin D synthesis - carries out the first step, liver and kidneys complete
4. Sensation - contains a variety of nerve endings that react to heat, cold, touch, texture, pressure, vibration, and injury
5. Thermoregulation - thermoreceptors monitor the body surface temperature
101
How does skin resist trauma and infection?
a. Epidermal cells are packed with keratin and linked by desmosomes, giving it durability
b. Skin is dry, slightly acidic and contains antimicrobial peptides
102
What are the other barrier functions of skin?
a. Barrier to water - prevents water gain and water loss
b. Barrier to UV rays which are cancer causing
c. Barrier to harmful chemicals
103
What does thermoregulation do?
a. When chilly - blood vessels of the dermis constrict, keeping warm blood deeper in the body
b. When overheating - blood vessels of the dermis dilate, allowing more blood to flow close to the surface and lose heat through skin
c. Sweat glands secrete sweat and sweat evaporation cools the body
104
What are the cells of the epidermis?
a. Stem cells - undifferentiated cells located in the stratum basale that divide and give rise to the keratinocytes
b. Keratinocytes - the majority of cells, they synthesize keratin
c. Melanocytes - synthesize the dark pigment melanin which is picked up by the keratinocytes to protect DNA from UV radiation
d. Tactile (Merkel) cells - receptors for touch
e. Dendritic cells - defense cells that migrate to the dermis
105
What are the abnormal colors of the skin and what do they mean?
a. Cyanosis - blueness from deficiency of oxygen in the blood
b. Erythema - redness caused by increased blood flow in dilated BV
c. Pallor - pale or ashen color from little blood flow through the skin
d. Albinism - milky white skin in people with a genetic lack of melanin
e. Jaundice - yellowing of the skin and white of the eyes from high levels of bilirubin in the blood
f. Hematoma - a mass of clotted blood showing through the skin
106
What are the Cutaneous Glands?
A. Sweat Glands (sudiferous)
B. Sebaceous Glands
C. Ceruminous Glands
D. Mammary Glands
107
What are the types of sweat glands and where are they located?
1. Apocrine sweat glands occur in the groin, anal region, axilla, and areola
2. Merocrine sweat glands are distributed over the entire body
108
What are apocrine sweat glands?
a. Ducts lead into hair follicles
b. Sweat is thicker and milkier because of fatty acids in it
c. Sweat glands that respond to stress and sexual stimulation
d. Clothing traps sweat allowing bacteria to degrade the fatty acids releasing a rancid odor - bromhidrosis
109
What are mericrine sweat glands?
a. The function is to cool the body
| b. Tube with duct leading to a sweat pore on the surface of the skin
110
What is Perspiration and Diaphoresis?
1. Perspiration - loss of about 500 mL of sweat per day
| 2. Diaphoresis - loss of up to 1 L of sweat per hour
111
What are Sebaceous Glands?
1. Glands that produce oily secretion (sebum)
2. The ducts open into a hair follicle
3. Sebum keeps skin and hair from drying
112
What are Ceruminous Glands?
1. Glands in the external ear canal that form part of the earwax (cerumen)
2. Cerumen keeps the eardrum flexible, waterproofs the canal, kills bacteria and coats the guard hairs blocking foreign particles from entering
113
What are Mammary Glands?
1. Milk-producing glands that develop during pregnancy and lactation
2. The glands are modified apocrine sweat glands that produce a richer secretion which is channeled through ducts to a nipple
114
What are the functions of the skeleton?
1. Support - bones hold up the body and provide support for muscles
2. Protection - bones enclose and protect vital organs
3. Movement - produced by the action of muscles on the bones
4. Electrolyte Balance - the skeleton stores calcium and phosphate ions and releases them into the tissue fluid and blood as needed
5. Acid-base Balance - bone tissue buffers the blood against excessive pH changes by absorbing or releasing alkaline phosphate or carbonate salts
6. Blood Formation - red bone marrow is the major producer of blood cells
115
What are the bone cells?
1. Osteogenic cells - stem cells in the endosteum and periosteum that multiply continually and give rise to osteoblasts
2. Osteoblasts - bone-forming cells that synthesize the organic matter of the bone matrix, which is hardened by mineral deposition
3. Osteocytes - former osteoblasts that have become trapped in lacunae in the matrix they deposited
4. Osteoclasts - bone-dissolving cells found on the bone surface
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What are lacunae?
Lacunae are interconnected by canaliculi which allow cells to pass nutrients and chemical signals and wastes to one another
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How are osteoclasts formed and where are they found?
a. They develop from bone marrow stem cells
| b. They reside in pits that they have etched into the bone surface
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What occurs during the healing of fractures?
a. Hematoma formation - bleeding in the bone causes a clot to form
b. Granulation of tissue - the clot is converted to granulation tissue by invasion of cells and blood capillaries
c. Soft callus formation - fibroblasts deposit collagen in the granulation tissue and chondroblasts produce fibrocartilage
d. Hard callus formation - osteoblasts deposit a bony collar around the fracture to unite the broken pieces
e. Bone remodeling - osteoclasts remove fragments of bone while osteoblasts deposit spongy bone then convert it to compact bone
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What are the ways to fix a fracture?
1. Closed reduction - a procedure in which bone fragments are manipulated into their normal positions without surgery
2. Open reduction - surgical exposure of the bone and the use of plates, screws, or pins to realign the fragments
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What are other bone disorders?
1. Rickets - soft bones in children from vitamin D deficiency
2. Osteomalacia - soft bones in adults from vitamin D deficiency
3. Osteitis deformans (Paget's disease) - excessive proliferation of osteoclasts with bone resorption and osteoblasts attempt to compensate by depositing extra bone
4. Osteomyelitis - inflammation of bone tissue and bone marrow as a result of bacterial infection
5. Osteogenesis imperfecta - a defect in collagen deposition that renders bones exceptionally brittle
6. Osteosarcoma - bone cancer most often in the tibia, femur, and humerus of males between 10 and 25
7. Osteoporosis - severe loss of bone density resulting in brittle bones with increase of fractures, especially in the hip, wrist, and vertebra
