7 Animal Integument Flashcards
The system that covers the outer of the animal body, including the skin and structures derived from it, such as hair, feathers, setae, and horns.
integumentary system
What are the functions of the integumentary system? (4)
- Protective wrapping
- Regulatory and Excretory functions
- Sensory Functions
- Behavioral interactions between individuals
What are the functions of the integumentary system’s protective wrapping? (4)
- mechanical protection
- a barrier against bacteria
- prevents fluid loss or gain; and
- protects underlying cells from UV radiation.
What are the functions of the integumentary system’s regulatory and excretory functions?
Osmo- and Thermoregulation , due to the presence of sweat glands and other structures.
What sensory functions are associated with the integumentary system? (4)
- thermoreceptor (senses heat/cold)
- Meissner’s corpuscles (senses touch)
- nociceptor (senses pain)
- Pacinian corpuscle (sense pressure)
What affects how individuals interact, and in some animals, such as snakes, coloration can signal whether they are venomous.
Pigmentation
Many protozoans have only a delicate cell or plasma membrane for __. __ functions for gas exchange, waste removal by simple diffusion, and uptake of dissolved nutrients.
- external covering
- Protozoan integument
What is the thick protein coat in some protozoans that provides environmental protection and transmits the force of cilia or flagella during movement? Give an example of organism that have this.
- Pellicle
- Ex.: Paramecium
What is the epidermis in multicellular invertebrates made of?
a single layer of columnar epithelial cells
Some invertebrates add a __ over the epidermis for additional protection. Give an example of organism that have this.
- noncellular cuticle
- Ex.: Nematodes
The molluscan epidermis is delicate, contains __, and secretes __ for the shell.
- mucous glands
- calcium carbonate
Compared to lower invertebrates, mollusks have a more complex integument consisting: (5)
- cuticle
- simple epidermis
- connective tissue
- iridocytes (reflecting cells)
- thicker connective tissue layer
The arthropod integument is the most complex of integument because their integument can perform __, with a hardened cuticle that serves as an __. Depending on the taxon of arthropod, the means of hardening could be one of the following processes that act on the __.
- skeletal functions
- exoskeleton
- procuticle layer
How is the arthropod cuticle hardened? (2)
- calcification (deposition of calcium carbonate, as in crustaceans)
- sclerotization (cross-linking of protein molecules, as in insects).
deposition of calcium carbonate, as in crustaceans
calcification
protein molecules bond together with stabilizing cross-linkages within and between adjacent lamellae of the procuticle. This protein is tough, highly resistance, and water insoluble. Observed in insects.
sclerotization
__ is a tough, highly resistant, and water-insoluble protein found in the __ of insects. It bonds together with stabilizing cross-linkages within and between adjacent __, contributing to the hardening of the exoskeleton in a process called sclerotization. This process strengthens the insect’s exoskeleton, making it more durable and protective.
- sclerotin
- procuticle
- lamellae
Why must arthropods molt or shed their exoskeleton?
their exoskeleton cannot grow with the animal, so they must shed it to accommodate growth.
The process by which arthropods shed their exoskeleton to accommodate growth. Since their exoskeleton cannot expand, molting allows the animal to grow a new, larger exoskeleton. This process is crucial for their development, but it temporarily leaves them vulnerable until the new exoskeleton hardens.
molting (ecdysis)
What are the steps involved in arthropod molting (ecdysis)? (5)
1) epidermal cells divide by mitosis
2) secretion of enzymes to digest the procuticle
3) absorption of digested material
4) formation of new epicuticle and procuticle; and
5) hardening of the new cuticle by calcification or sclerotization.
The vertebrate integument is the __ and its __.
- skin
- derivatives
What are the two main layers of vertebrate skin?
- epidermis
- dermis
is not part of the skin; it is a layer of loose connective tissue, adipose tissue, and nerve endings that separates the skin from deeper tissues.
hypodermis
- made up of stratified keratinized squamous epithelium.
- It is devoid of blood vessels, i.e., it is avascular.
- Cells of the basal part undergo frequent mitosis to replace the outer layer of cells.
- New generations of cells undergo keratinization, which make the cells
cornified—cells that are highly resistant to abrasion and water diffusion
Epidermis
What type of tissue makes up the epidermis?
stratified keratinized squamous epithelium
Epidermis have new generations of cells undergo __, which make the cells __—cells that are highly resistant to abrasion and water diffusion
- keratinization
- cornified
The epidermis is __, meaning it has no blood vessels.
avascular
What are the layers of epidermis? (5)
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
- the deepest cell layer of the epidermis, located closest to the dermis.
- contains only one layer of cuboidal stem cells that receive adequate nourishment through diffusion of nutrients from the dermis.
- The cells constantly undergo cell division, and millions of new cells are produced daily. The daughter cells are pushed upward, away from the source of nutrition, to become part of the epidermal layers closer to the skin surface.
stratum basale or stratum germinativum
The stratum basale contains a single layer of __ that undergo cell division to produce new cells that move toward the skin surface.
- cuboidal stem cells
Cells in the stratum basale receive nourishment through __ of nutrients from the __.
- diffusion
- dermis
- a layer in epidermis found right above the stratum basale and is about 8-10 cell layer thick.
- ## Cells from the stratum basale migrate to this layer to undergo important changes as they continue to go upward.
Stratum spinosum
The stratum spinosum is located above the __ and is about __ cell layers thick.
- stratum basale
- 8-10
Two of the changes observed in the cells found in the stratum spinosum (2)
- conversion of the cuboidal cells into keratinocytes
- presence of many desmosomes that adjoin adjacent cells.
In the stratum spinosum, cuboidal cells convert to __ and develop numerous __, giving them a spined appearance, hence the name “spinosum”.
- keratinocytes
- desmosomes
join adjacent cells, providing strength and creating the spined appearance of cells in the stratum spinosum.
desmosomes
- a layer in the epidermis located above the stratum spinosum and is about 3-5 cell layers thick.
- Cells in this layer assume the flattened appearance. Cells also start to produce keratin and keratohyalin, the proteins that cause the grainy appearance of cells in this layer.
- Cells in this layer start to die, i.e., they start to lose their nuclei and other organelles. What remain in the cells in this layer are the keratin and keratohyalin, which will form the outermost skin layer, nails, and hairs.
Stratum granulosum
The stratum granulosum is located above the __ and is about __ cell layers thick.
- stratum spinosum
- 3-5
Cells in the stratum granulosum become flattened and grainy due to the production of __ and __ proteins. These proteins contribute to forming the outermost skin layer, nails, and hair.
- keratin
- keratohyalin