Module 7 - Integumentary System Flashcards
What is the integumentary system comprised of?
skin, hair, nails.
What is the largest organ of the body?
Skin
How many layers are there in the skin?
3
Name the 3 layers of the skin:
- Epidermis
- Dermis
- Hypodermis
What is the outer layer of the skin called?
Epidermis
What is the middle layer of the skin called?
Dermis
What is the inner layer of the skin called?
Hypodermis (also called the subcutaneous layer)
What is another name of the hypodermis?
The subcutaneous layer
How is the skin related to bone development?
Skin is related to bone development because skin cells absorb ultraviolet radiation to produce vitamin D, which is used to promote bone development.
What is the integumentary system responsible for?
Plays a role in protecting internal organs from extreme temperature changes as well as pathogenic (disease-causing) microorganisms.
What happens if the integumentary system is damaged and microbes or foreign objects make their way into the body?
The lymphatic system is responsible for mounting the attach to defend the body’s internal environment
Identify structures 1-6 on Figure 7.1
- Epidermis
- Dermis
- Hypodermis
- Subcutaneous fat
- Subcutaneous tissue
- Basement membrane
What is the epidermis adhered to?
The basement membrane
What are sensory organs?
Sensory organs are specialized organs embedded into the skin that are designed to detect sensory information and relay that information to the brain.
Name 5 different types of sensory organs related to the skin?
- Merkel’s cells
- Meissner’s corpuscles
- Nociceptors
- Pacinian corpuscles
- Thermoreceptors
Name 2 different kinds of mechanorecepters and what they do:
- Merkel’s cells
- Meissner’s corpuscles
Mechanoreceptors are sense organs that detect mechanical sensory information in the form of light touch and vibration.
What do nociceptors detect?
Nociceptors detect pain, such as from a pin prick.
What type of sense organ is responsible for detecting pressure that is being applied to the skin?
Pancinian corpuscles. They detect mechanical sensory information on pressure applied to the skin.
What do thermoreceptors detect?
Thermoreceptors detect hot and cold.
Identify structures 1-5 on figure 7.2
- Epidermis
- Merkel cell
- Meissner’s corpuscles
- Pacinian corpuscle
- Sensory nerve
What is an exocrine gland?
Exocrine glands contain secretions released through a duct (opening) into an epithelial surface or lining.
What is a duct?
An opening into an epithelial surface or lining through which secretions are released in exocrine glands
Define multicellular glands
Most glands in body are multicellular.
They are set within epithelial tissue and release their contents through a duct to the surface.
Define sebaceous gland
Oil gland that produces sebum.
What does sebum do and where does it come from?
Sebum helps to keep the skin and hair from drying out and inhibits the growth of harmful microorganisms. Sebum comes from sebaceous glands.
Define sweat gland
sudoriferous gland.
Produce sweat in almost every part of the skin. The secretory portion of a sweat gland is deep within the dermis layer of the skin.
The duct extends all the way through the dermis, through the epidermis to release its contents on the external surface.
Define perspiration
the release of sweat
What does perspiration do?
It helps the body regulate its temperature through a process called thermoregulation.
What is the process of thermoregulation?
It is the release of heat from the body (typically, through perspiration)
Identify structures 1-4 on figure 7.3
- Epidermis
- Sweat gland
- Oil
- Sebaceous gland
What is the epidermis made up of?
stratified squamous epithelium
What is stratified squamous epithelium?
layered and flat
Define avascular
when a structure does not have a direct blood supply.
Where does the epidermis receive its nutrients from?
The basement membrane
How many layers is the epidermis comprised of?
4
List the 4 layers of the epidermis from superficial to deep.
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
Where does the epidermis get it’s blood supply from?
The stratum basale (the deepest layer of the epidermis), is firmly adhered to the basement membrane, which contains the blood supply for the epidermis.
How does the stratum basale rebuild the skin?
The stratum basale cells are constantly dividing, then they are pushed towards the external surface until they are dead and slough off.
Why is the most superficial layer of skin (epidermis) dead?
Because it is farther away from the blood and nutrient supply of the basement membrane.
How long does it take for a single cell to move from the stratum basale to the external surface of the stratum corneum?
30 days
How long do the dead cells remain within the stratum corneum?
Roughly 2 weeks before they slough off.
What layer of the epidermis produces epidermal ridges?
The stratum basale
How is the epidermis related to a person’s “fingerprints”?
The stratum basale forms the epidermal ridges, which are unique to each person and are consistent throughout a person’s lifetime. These projections extend all the way through the epidermis and form a distinct pattern, commonly referred to as fingerprints.
Identify the layer of skin in figure 7.4 as well as structures 1-5
This is the epidermis
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
- Dermis
Name 5 different types of cells that can be found in the epidermis
- Keratinocytes
- Langerhans cells
- Fibroblast cells
- Melanocytes
- Merkel cells
What do melanocytes do?
Produce a pigment called melanin
What are Langerhans cells involved in?
The body’s immune response- they act as the body’s first line of defense, helping to identify microorganisms before they reach the bloodstream.
What are merkel cells?
Merkel cells are a type of sensory receptor that respond to light touch.
What do keratinocytes produce? What does it do?
Keratinocytes produce a tough substance called keratin. Cells within the epidermis undergo keratinization, which protects exposed surfaces of skin.
What are fibroblast cells?
Fibroblast cells produce collagen, which helps to adhere the cells of the epidermis to each other and give the skin elasticity
Identify cells 1-5 in figure 7.5
- Keratinocytes
- Melanocytes
- Langerhans cells
- Fibroblast cells
- Merkel cells
In what layer of the skin can Meissner corpuscles and Pacinian corpuscles be found?
The dermis
How many layers is the dermis comprised of?
2
Name the layers found within the dermis from superficial to deep
- papillary region
2. reticular region
Which layers of the dermis contain collagen fibers and elastic fibers?
Both (papillary region and reticular region)
Does the dermis or the epidermis have a higher water content?
The dermis
How can you check for dehydration?
You can pinch the skin on the back of one’s hand and if it does not recoil back to its normal shape but instead stays pinched, this is indicative of dehydration (decreased water content in the dermal layer of skin)
What does the reticular region of the dermis do?
It contains the main blood supply for the skin.
What is a bruise?
Also known as a contusion, a bruise is damage to one of the blood vessels found in the dermis. Blood leaks out of a vessel into the dermis, creating the color of a bruise (typically black and blue).
Identify structures 1-8 in figure 7.6
- basement membrane
- dermis
- papillary region
- reticular region
- artery
- nerve
- vein
- hypodermis
What type of cells does the hypodermis mostly consist of?
fat cells (adipocytes)
How many layers are there in the hypodermis?
2
Name the layers found in the hypodermis
- subcutaneous fat
2. subcutaneous tissue
What is one function of the hypodermis and why is important?
The hypodermis anchors the dermis to a layer of fat cells. The fat helps to insulate and regulate body temperature. The thickness of the hypodermis protects the deeper tissues and organs from injury.
What is a subcutaneous injection?
A medication or vaccination that is given in a needle that reaches the dermis, but superficial to the muscle (in the hypodermis layer of the skin).
Is medication that is given through a subcutaneous injection absorbed by the body more slowly than if given directly into a vein?
Yes.
Define a dermatome
A dermatome is a region of skin innervated by one sensory nerve.
Where do sensory signals from the skin typically get sent to?
The spinal nerve through the spinal cord (and finally, to the brain for processing).
Is every region of the skin innervated by a spinal nerve?
No, the face is innervated by a cranial nerve (CN V: trigeminal nerve).
Label spinal regions 1-4 for which region of the spine receives information from the skin on figure 7.7
- Cervical spinal nerves
- Thoracic spinal nerves
- Lumbar spinal nerves
- Sacral spinal nerves
What are the two parts of the hair?
- the root
2. the shaft
Where does the root of the hair begin?
In the dermis layer at the hair bulb, which has blood and nervous supply.
Describe the positioning of the hair shaft
The shaft extends through the epidermis to the external surface of the skin.
What is hair made up of?
Hair is made up of dead epidermal cells that are converted to keratin, giving the hair its stronger texture compared to other skin cells.
what type of gland is found at the root of each hair follicle?
A sebaceous gland
What does the gland found at the root of each hair follicle responsible for?
Helping to hydrate hair with oil
What is each hair follicle connected to?
An arrector pili muscle
What is an arrector pili muscle?
It is a smooth muscle that contracts when the body is cold or experiences emotional responses.
Where can hair follicles be found and what are they susceptible to?
They can be found throughout the surface of the skin and are susceptible to circulating hormones.
Label structures 1-9 on figure 7.8
- Shaft
- root
- Sebaceous gland
- Arrector pili muscle
- Matrix
- Papilla
- Melanocytes
- Bulb
- Blood vessels
What are nails composed of?
Dead epidermal cells that are converted to keratin
Where are new cells converted? (in relation to nails)
At the nail root, then they are pushed towards the external surface in the direction of the nail body.
What is the nail body?
The visible portion of a nail, covering the epidermis in that region, called a nail bed.
Is the nail root visible?
No
What is the nail body?
The visible portion of the nail, covering that epidermis in that region, called the nail bed.
What is the cuticle?
The stratum corneum of the epidermis extends from the nail root covering the visible portion of the nail.
What is the lunula?
The visible portion of the nail bed near the nail root, which is typically crescent shaped (and most visibly on the thumbs).
Identify structure 1-9 on figure 7.9
- Nail root
- Nail matrix
- Cuticle
- Lunula
- Nail body
- Phalanx (finger bone)
- Dermis
- Hypodermis
- Epidermis
What is a cell?
The smallest unit of life
Cells come together to form what?
Tissues
What are tissues?
Tissues are comprised of cells, which are similar in structure and function. Tissues are also comprised of matrix.
What is matrix?
A.K.A extracellular material, made up of ground substances (extracellular fluid), protein, and collagen fibers. When the skin is damaged, both tissue and matrix need to be repaired.
What is a clot?
Blood platelets from the broken blood vessel start to accumulate in the area where the tissue was damaged. This secretes a mesh-like substance around it to prevent blood loss. This is the first step in the tissue repair process.
Describe what is happening in Figure 7.10. What 3 things are being shown?
Tissue damage- skin is cut by a foreign object.
- Tissue damage
- Foreign object
- Broken blood vessel
Describe what is happening in Figure 7.11. Identify structures 1-4.
Tissue repair, platelets are gathering in the broke blood vessel to form a clot.
- Broken blood vessel
- Red blood cell
- Platelets form a clot with mesh
- Platelets
What do mast cells do?
They release histamine
What is histamine?
It is a chemical that helps dilate blood vessels to bring increased blood and nutrients to the injured area. Histamines helps to initiate a local inflammatory response, which signals other cells in the area to help remove foreign pathogens.
What are macrophages?
A type of white blood cell that works to engulf and destroy disease-causing pathogens.
What are fibroblasts?
They are cells that help to secrete new collagen in the shape of old tissue. The collagen framework supports the tissue matrix in the shape of the old cells until new cells are fully developed.
Describe what is happening in Figure 7.12. Identify structures 1 and 2.
Fibroblasts secrete a collagen matrix in the shape of the original tissue.
- Damaged tissue
- Fibroblasts
Describe what is happening in Figure 7.13. Identify structures 1 and 2.
Collagen network fills in the damaged area as the cells divide and mature.
- Damaged tissue
- Collagen secreted by fibroblasts
What is the final stage of wound healing?
Remodeling- where the tissue matures, and the cells begin to take on their original functions.
What are scars and why do they occur?
A scar is an overgrowth of the fibrous connective tissue that cannot be fully replaced by the original tissue.
This occurs when the wound is too deep in the tissue. Some of the original function of the tissue is lost.
Describe what is happening in Figure 7.14. Identify structure 1.
Tissue remodeling: Cells divide, mature, and fully replace the damaged tissue.
- Repaired tissue
Describe one way to classify burns and name the 4 types for this type of classification of burns?
By the severity of the burn. There are 4 classifications:
- First degree burn
- Second degree burn
- Third degree burn
- Fourth degree burn
Describe a first degree burn and provide an example.
A first degree burn is a superficial burn, that only causes damage to the epidermis layer of the skin. The burned area becomes dry, red, and painful, without blistering. An example is a mild sun burn that does not blister.
What type of burn is shown in Figure 7.15? How do you know?
First degree burn, because there are no blisters on the skin.
Describe a second degree burn:
A second degree burn is also called a partial thickness burn, which causes damage to the epidermis layer of the skin. The burn turns red and forms blisters, becoming painful and swollen. Since the dermis has many sensory organs embedded within it, this kind of burn is painful.
What type of burn is shown in Figure 7.16? How do you know?
Second degree burn, because there are blisters on the the skin.
Describe a third degree burn:
A third degree burn is also known as a full thickness burn, which causes damage to the epidermis, entire dermis, and may extend slightly into the subcutaneous layer of the skin. The injured skin typically looks white and may even have a “charred” appearance. The extensive damage to the dermis layer of the skin makes third degree burns extremely painful.
What type of burn is shown in Figure 7.17? How do you know?
Third degree burn, because of the white/charred appearance.
Describe a fourth degree burn:
A fourth degree burn damages the epidermis, dermis, hypodermis, and underlying tissue such as muscle or bone. Because the nerves endings are destroyed, there is no sensation in the affected burn area.
What is skin grafting and when is it used? Name some benefits of this treatment.
Skin grafting is a treatment where healthy skin is taken from a person’s own body and grafted on top of the damaged area. Skin grafting decreases recovery time and prevents infection. It may be necessary if the skin has been too severely damaged or if the burn covers a large surface area.
