Lecture Exam 2 Study Guide
Tissues:
• Distinguish “blast” from “cyte”
o Blasts: Young cells that are still secreting extracellular matrix
▪ Osteoblasts: Secreting osteoid
o Cytes: Mature cell that is no longer secreting extracellular matrix
▪ Osteocytes: No longer secreting but they are maintaining the extracellular matrix that is
around them
• Briefly describe each tissue type discussed in lecture, distinguishing them by their structure, function,
and location in the body
o Lecture 7/8?
o Stratified squamous epithelium: Multiple layers of flattened cells. It is found on your epidermis,
plays a protective role for your skin
• Describe/ define the extracellular matrix (generally)
o The ECM is stuff secreted by connective tissue cells.
o For the majority of connective tissue, the ECM makes up the majority of the tissue by volume
▪ Not the case of adipose tissue.
o Ex: Bone secretes osteoid which is the organic portion of the ECM in bone which accumulates
hydroxyapatites: calcium phosphate salts which are the inorganic portion of bone that hardens it.
o ECM is made up mostly of protein fibers and also has glycoproteins, glycolipids, water that the
fibers interact with.
▪ Those fibers are mostly collagen (really tough protein – most abundant protein in your
body that is good at resisting tensile forces).
▪ Elastic fibers have give and allow elasticity to a tissue
▪ Reticular fibers, short, branched collagen fiber playing an immune fiber because WBC
leukocytes hang out on them and monitor liquids that are passing through the tissue.
o Bone as an example: the osteoid is mostly collagen fibers and those accumulate calcium
phosphate salts
Integument:
• Describe the basic functions of the integumentary system
o Protection, barrier to outside world, thermoregulation (vessels can dilate or constrict), cutaneous
sensations (interactions with outside world – touch receptors, thermoreceptors)
o Hair acts as another touch receptor – is sensitive to bending – can feel a breeze on your skin
since the hairs on your skin are bending in response
o Metabolic functions: synthesizes a vitamin D precursor
• Overview each of the epidermal layers and any defining characteristics, especially as they relate to the
maturation of the primary epidermal cells
o They migrate up through the different layers as they mature
o Stratum basale: Cells are born in the stratum basale (the deepest layer of the epidermis), the only
mitotic layer. When the cells undergo mitosis, some cells remain there as stem cells and other
cells become keratinocytes that will continue moving up through the layers
o Stratum spinosum: Cells begin to dehydrate and prekeratin begins to form
▪ It is getting spiney because it is dehydrating so the cells begin shrinking in volume
o Stratum granulosum: Prekeratin is becoming keratin and by the time the cells have moved to the
stratum granulosum, they are far enough from blood supply that they can no longer receive
nutrients or oxygen.
▪ Cells die in this layer
▪ There are some granules there which make the slide a little bit darker.
, o Stratum lucideum: If it is thick skin, the cells will enter the stratum lucidem (Only if it is thick
skin- palms of your hand and soles of your feet)
o Stratum corneum: Outer layer, thickest layer
▪ 25-30 rows of flattened keratocytes (corneocytes).
▪ Keratin is a thick protein that helps waterproof the skin, and protects skin to abrasion
o Then they flake off. There are enzymes that will digest the linkages to the desmosomes and
allow the cells to individually flake off.
• Distinguish the two layers of the dermis, noting fiber types and functional differences
o Papillary layer: Does have some touch receptors
o Reticular layer: Deeper layer, is more dense, thicker and tougher
o In both layers you have collagen and elastic fibers
• Explain the purpose/ importance of friction ridges and Langer’s lines
o Friction ridges: Fingertips – help you grip stuff and aid in sensation. They vibrate when you run
them across surfaces
o Langer’s lines: Lines across the body formed via bundles collagen fibers within the dermis and
they are useful mostly for surgery. Because you want to cut down the length of the line instead of
across it.
• Overview the structure and function of sweat glands, oil glands, and nails
o Eccrine sweat glands: Thermoregulation
▪ Many of them
o Apocrine sweat glands: Fewer of them. Only found in axillary and genital regions
▪ Start working at puberty
▪ Are mostly human scent glands
▪ Your immune system is related to types of proteins that get secreted in apocrine sweat
glands and that sebum interacts with bacteria and creates BO which is unique to your
immune system. And your immune system is connected to your DNA and you end up
being attracted to people with a very different immune system than you
o Nails: Fine grip, help with sensation if you bang it on things
o Oil Glands (Sebaceous glands): Connect to hair follicles and they secrete oil.
▪ The oil softens and waterproofs hair.
▪ It also slightly softens your skin to protect it
▪ They become really active at puberty
• Skin become oily and acne becomes common
• Describe the structure, functions, and growth of the two hair types
o Vellus hair: Refined body hair that we all have and covers most of our body
o Terminal: Thicker, coarser, longer, much more deeply colored hair
▪ Is on our head, eyebrows, and eyelashes (where it helps protect our eyes), anogenital
area, axillary area.
▪ And the degree to which it is found on other parts of the body is regulated by different
hormone aspects – especially testosterone
• Testosterone prompts this kind of hair growth on areas like face, chest, back, etc.
• Distinguish alopecia from balding and explain genetic determinants of your odds of balding
o Alopecia: Generic hair thinning we will all get
o Balding: True balding is more common in males because it is transmitted on the X chromosome
and the genes are mostly recessive which means as a female you have 2 Xs. So, if you have
recessive balding genes on one X, your odds are that on the other X chromosome, the genes do
not code for balding and that is what will be expressed because it is dominant. However, if you
are male, you only have 1 X chromosome and you got it from mom, and if those genes say you
are going to go bald, you will go bald since it is recessive.
o Your best guess as to whether you will bald is to look at your mom’s dad because whatever X
you got from your mom, there is a 50/50 chance it came from her dad.
Tissues:
• Distinguish “blast” from “cyte”
o Blasts: Young cells that are still secreting extracellular matrix
▪ Osteoblasts: Secreting osteoid
o Cytes: Mature cell that is no longer secreting extracellular matrix
▪ Osteocytes: No longer secreting but they are maintaining the extracellular matrix that is
around them
• Briefly describe each tissue type discussed in lecture, distinguishing them by their structure, function,
and location in the body
o Lecture 7/8?
o Stratified squamous epithelium: Multiple layers of flattened cells. It is found on your epidermis,
plays a protective role for your skin
• Describe/ define the extracellular matrix (generally)
o The ECM is stuff secreted by connective tissue cells.
o For the majority of connective tissue, the ECM makes up the majority of the tissue by volume
▪ Not the case of adipose tissue.
o Ex: Bone secretes osteoid which is the organic portion of the ECM in bone which accumulates
hydroxyapatites: calcium phosphate salts which are the inorganic portion of bone that hardens it.
o ECM is made up mostly of protein fibers and also has glycoproteins, glycolipids, water that the
fibers interact with.
▪ Those fibers are mostly collagen (really tough protein – most abundant protein in your
body that is good at resisting tensile forces).
▪ Elastic fibers have give and allow elasticity to a tissue
▪ Reticular fibers, short, branched collagen fiber playing an immune fiber because WBC
leukocytes hang out on them and monitor liquids that are passing through the tissue.
o Bone as an example: the osteoid is mostly collagen fibers and those accumulate calcium
phosphate salts
Integument:
• Describe the basic functions of the integumentary system
o Protection, barrier to outside world, thermoregulation (vessels can dilate or constrict), cutaneous
sensations (interactions with outside world – touch receptors, thermoreceptors)
o Hair acts as another touch receptor – is sensitive to bending – can feel a breeze on your skin
since the hairs on your skin are bending in response
o Metabolic functions: synthesizes a vitamin D precursor
• Overview each of the epidermal layers and any defining characteristics, especially as they relate to the
maturation of the primary epidermal cells
o They migrate up through the different layers as they mature
o Stratum basale: Cells are born in the stratum basale (the deepest layer of the epidermis), the only
mitotic layer. When the cells undergo mitosis, some cells remain there as stem cells and other
cells become keratinocytes that will continue moving up through the layers
o Stratum spinosum: Cells begin to dehydrate and prekeratin begins to form
▪ It is getting spiney because it is dehydrating so the cells begin shrinking in volume
o Stratum granulosum: Prekeratin is becoming keratin and by the time the cells have moved to the
stratum granulosum, they are far enough from blood supply that they can no longer receive
nutrients or oxygen.
▪ Cells die in this layer
▪ There are some granules there which make the slide a little bit darker.
, o Stratum lucideum: If it is thick skin, the cells will enter the stratum lucidem (Only if it is thick
skin- palms of your hand and soles of your feet)
o Stratum corneum: Outer layer, thickest layer
▪ 25-30 rows of flattened keratocytes (corneocytes).
▪ Keratin is a thick protein that helps waterproof the skin, and protects skin to abrasion
o Then they flake off. There are enzymes that will digest the linkages to the desmosomes and
allow the cells to individually flake off.
• Distinguish the two layers of the dermis, noting fiber types and functional differences
o Papillary layer: Does have some touch receptors
o Reticular layer: Deeper layer, is more dense, thicker and tougher
o In both layers you have collagen and elastic fibers
• Explain the purpose/ importance of friction ridges and Langer’s lines
o Friction ridges: Fingertips – help you grip stuff and aid in sensation. They vibrate when you run
them across surfaces
o Langer’s lines: Lines across the body formed via bundles collagen fibers within the dermis and
they are useful mostly for surgery. Because you want to cut down the length of the line instead of
across it.
• Overview the structure and function of sweat glands, oil glands, and nails
o Eccrine sweat glands: Thermoregulation
▪ Many of them
o Apocrine sweat glands: Fewer of them. Only found in axillary and genital regions
▪ Start working at puberty
▪ Are mostly human scent glands
▪ Your immune system is related to types of proteins that get secreted in apocrine sweat
glands and that sebum interacts with bacteria and creates BO which is unique to your
immune system. And your immune system is connected to your DNA and you end up
being attracted to people with a very different immune system than you
o Nails: Fine grip, help with sensation if you bang it on things
o Oil Glands (Sebaceous glands): Connect to hair follicles and they secrete oil.
▪ The oil softens and waterproofs hair.
▪ It also slightly softens your skin to protect it
▪ They become really active at puberty
• Skin become oily and acne becomes common
• Describe the structure, functions, and growth of the two hair types
o Vellus hair: Refined body hair that we all have and covers most of our body
o Terminal: Thicker, coarser, longer, much more deeply colored hair
▪ Is on our head, eyebrows, and eyelashes (where it helps protect our eyes), anogenital
area, axillary area.
▪ And the degree to which it is found on other parts of the body is regulated by different
hormone aspects – especially testosterone
• Testosterone prompts this kind of hair growth on areas like face, chest, back, etc.
• Distinguish alopecia from balding and explain genetic determinants of your odds of balding
o Alopecia: Generic hair thinning we will all get
o Balding: True balding is more common in males because it is transmitted on the X chromosome
and the genes are mostly recessive which means as a female you have 2 Xs. So, if you have
recessive balding genes on one X, your odds are that on the other X chromosome, the genes do
not code for balding and that is what will be expressed because it is dominant. However, if you
are male, you only have 1 X chromosome and you got it from mom, and if those genes say you
are going to go bald, you will go bald since it is recessive.
o Your best guess as to whether you will bald is to look at your mom’s dad because whatever X
you got from your mom, there is a 50/50 chance it came from her dad.
