M1, S4, Integumentary System Flashcards
A precursor form of which vitamin is produced in the skin?
Vitamin D
As cells of the outer surface of the epidermis are continually being sloughed off, some cells in the stratum ______ (the bottom layer) of the epidermis divide continuously, replenishing the epidermis.
basale
What are the two sub-layers of the dermis?
- Papillary region
2. Reticular region
The reticular region usually constitutes approximately __% of the dermis.
80%
______ helps to protect the skin and underlying tissue from harmful UV radiation
Melanin
What are the three pigments that contribute towards skin color?
Melanin, carotine, hemoglobin
Carotene is a precursor to vitamin __.
A
Which of the following cell types are usually found in the epidermis?
- keratinocytes
- melanocytes
- erythrocytes
- Langerhans cells
- T cells
- keratinocytes
- melanocytes
- Langerhans cells
Which of the following is the most significant determinant of skin color?
- location of melanocytes
- number of melanocytes
- amount of melanocytes
-AMOUNT of melanocytes
Cells multiply at the basement membrane and move toward the surface, becoming increasingly __________. As they move away from the nutrients of the dermis, they die and flake away on reaching the surface.
keratinized
Approximately 90% of epidermal cells are ___________.
keratinocytes.
These cells are part of the immune system and can recognize foreign microbes, engulf and destroy them, and present their antigens to the immune system for further action.
Langerhans cells
________ cells are found at the border between the epidermis and the dermal layer. They have small dendrites that protrude in between nearby keratinocytes in the stratum spinosum.
Merkel cells
The most superficial layer of the epidermis, consisting of 20-30 layers of dead keratinocytes.
Stratum corneum
A single layer of cuboidal-shaped cells on a ______ membrane. This layer contains stem cells, keratinocytes, and melanocytes. It is also sometimes called the stratum germinativum , due to its role in cell germination, i.e., new skin cells are produced at the basal membrane pushing the older cells towards the surface.
basal
In which of the following locations is the stratum lucidium found?
- armpits
- groin
- soles of the feet
- fingertips
- chin
- soles of the feet
- fingertips
Skin with hair is commonly referred to as ____ skin
thin
Hairless skin is often called _____ skin.
thick
________ growth factors are associated with the overall regulation of skin growth.
Epidermal
_______ strengthens the cells, while ________ adhere the cells to one another and are responsible for the waterproof properties of skin.
Keratin, glycolipids
What is the name of the molecule that is produced by lamellar granules in the stratum granulosum?
Glycolipid
Which of the following epidermal strata contains the most live cells?
Stratum basale
_________ glands produce sebum, an oily secretion that prevents the hair and skin from becoming brittle and dry
Sebaceous
What are the two types of sweat glands?
Merocrine and apocrine glands
________ perspiration is when sweat is secreted and forms a visible layer, whereas _________ perspiration is when sweat is secreted, but evaporates before a visible layer is formed.
Sensible, insensible
_________ are the more abundant of the two types of sweat glands and are found all over the skin.
High concentrations are found on the palms of the hands and soles of the feet.
Opens directly onto the surface of the skin as a sweat pore.
Merocrine, Thermoregulation
________ glands are large sweat glands that develop during puberty, and are mainly located in the armpits and anogenital areas.
Apocrine
Which gland does NOT contribute to thermoregulation?
Apocrine glands
________ glands are modified apocrine sweat glands located deep in the subcutaneous layer of the external ear.
Ceruminous
The ____ is an onion-shaped structure deep in the dermis, where cell growth occurs.
bulb
Formed by two or three layers of irregularly shaped cells, located in the center of a hair.
Cortex, medulla, cuticle?
Medulla
Layers of elongated cells surrounding the medulla, forming a significant part of the hair structure.
Cortex, medulla, cuticle?
Cortex
A single layer of thin, flat cells that are heavily keratinized. Each cell partially overlaps the cuticle cell superficial to it, with the exposed edge pointing upwards.
Cortex, medulla, cuticle?
Cuticle
Within the bulb is an indentation called the _____, which contains blood vessels and connective areolar tissue.
papilla
A germinal layer of cells, called the _____ _____, surrounds the papilla of the hair and gives rise to all cells within a hair, including the internal root sheath.
hair matrix
This muscle causes hair to stand on end in what is commonly known as ‘goose bumps’.
This action has a major role in thermoregulation for animals with thick fur, but in humans it of minor importance.
Arrector pili muscle
Which of the following substances are found in the bulb of the hair?
- melanocytes
- cuticle
- papilla of the hair
- hair matrix
- medulla
- melanocytes
- papilla of the hair
- hair matrix
The white, half-moon-shaped area at the proximal end of the nail.
Lunule
_________ ________ are egg-shaped, encapsulated masses of dendrites.
Messner’s corpuscle
________ ________ are large oval structures, consisting of a dendrite wrapped in a multilayered, connective tissue capsule.
Involved in sensing PRESSURE.
Pacinian corpuscle
They are flattened, saucer-shaped free nerve endings.
Merkel disc
Besides tactile sensation, thermoreception and proprioception, what is the fourth type of somatic sensation?
pain
Cold receptors can be found in the stratum _______.
basale
Warm receptors can be found in the _______.
dermis
Special pain receptors are called _________.
nociceptors
_______ pain is a phenomenon that occurs when pain is felt in a different location to the site of the causative injury.
Referred
Which of the following sensory receptors are responsible for the touch sensation?
- free nerve ending
- hair root plexus
- Pacinian corpuscle
- Merkel disc
- Messner’s corpuscle
- hair root plexus
- Merkel disc
- Messner’s corpuscle
T/F: Pacinian corpuscles detect higher-frequency vibrations
True
Which of the following receptors respond to VIBRATION?
- Merkel discs
- hair root plexus
- Pacinian corpuscles
- Messner’s corpuscles
- thermoreceptors
- Pacinian corpuscles
- Messner’s corpuscles
Epithelial cells produce cationic proteins called _______ which have antimicrobial properties and help prevent the colonization of the skin.
defensins
_________ is the transfer of heat away from an object via the movement of gases or fluids.
Convection
Which of the following help the skin to act as a barrier against microbes?
- glycolipids
- sweat
- normal flora
- melanin
- defensins
- sweat
- normal flora
- defensins
What is the name given to the formation of scar tissue during the final phase of deep wound healing?
fibrosis
Fibrin and blood platelets form a blood clot in the wound to prevent further blood loss and to seal the injury from the external environment. This is known as __________.
hemostasis
Which one of the following cell types produces scar tissue?
- reticular cells
- fibroblasts
- macrophages
- adipocytes
- phagocytes
-fibroblasts
