LO 4 Flashcards
1
Q
______ is anatomically simple but functionally important sheet like structures called membranes
A
Skin
2
Q
______ is another name for the skin and the connective tissue underneath
A
Integument
3
Q
_________ is the integument when considered as a body system
A
Integumentary system
4
Q
Hair, nails, and skin glands are examples of _________
A
Skin appendages
5
Q
Describe membranes
A
- Thin, sheet-like structure found throughout the body
- Covers and protect internal and external surfaces and organs
- Anchors organs and bones
- Secrete lubricating fluids to reduce friction
6
Q
What are the 2 major types of membranes in the body?
A
- Epithelial membranes (2 distinct layers - epithelial tissue and underlying layer of connective tissue)
- Connective tissue membranes - composed largely of various types of connective tissue
7
Q
What are the 3 types of epithelial membranes?
A
- Cutaneous membrane - the skin
- Serous membrane - parietal + visceral
- Mucous membrane
8
Q
Describe the cutaneous membrane (the skin)
A
- Primary organ of the integumentary system
- Largest and and one of the most visible organs - 16% of body weight
- Made up of superficial layer of epithelial cells + underlying layer of supportive tissue
9
Q
Describe the serous membrane
A
- Made of 2 layers:
i. Epithelial layer: thin layer of simple squamous epithelium ii. Connective tissue layer: very thin, glue-like basement membrane (holds and supports the epithelial cells)
Also secretes lubricating fluid to decrease friction
10
Q
What are the 2 types of serous membrane?
A
- Parietal - lines the walls of body cavities (e.g. peritoneum in thoracic cavity)
- Visceral - covers organs in body cavities (e.g. visceral pleura on lungs)
11
Q
Serous membranes can be easily visualized with this analogy
A
- Fist pushing into a water balloon
- Demonstrates how serious membranes form a double-walled structure containing a thin pocket of fluid (e.g. heart is surrounded by serous paracardium)
12
Q
Describe 2 serous membrane diseases
A
- Pleaurisy - inflammation of the serous membranes that line the chest cavity and cover the lungs (i.e. the pleura)
- Peritonitis - inflammation of the serous membranes that line the walls of the abdominal cavity and cover the abdominal organs (i.e. the peritoneum)
13
Q
Describe mucous membranes
A
- Line surfaces the open directly to exterior of body (lining of respiratory, digestive, urinary, and reproductive tracts)
- Epithelial portion varies depending on location and function
- Epithelial cells produce mucous to keep the membranes soft and moist
14
Q
________ is the transitional area where the skin and mucous membranes meet
A
Mucocutaneous junction (eyelids, nostrils, anus)
15
Q
Describe connective tissue membranes
A
- Do not contain epithelial components
- Produce lubricant called synovial fluid
- Examples are synovial membranes between joints and the lining of the bursae (cushion-like sacks found between many moving body parts)
16
Q
What are the 2 primary layers of the skin?
A
- Epidermis
- Dermis
17
Q
Describe the supporting layer of the skin (hypodermis)
A
- Loose connective tissue
- Fat - insulation from extreme heat, alternative source of energy, protective cushion
18
Q
Describe the epidermis
A
- Outer most layer of skin
- Relatively thin sheet of stratified squamous epithelium
- Arranged in up to 5 distinct layers
19
Q
Describe the stratum germintativum (also called stratum basal or basal layer)
A
- Is the inner-most layer of the epidermis
- Continuously undergoes mitosis
- New cells are pushed upward through additional layers “strata” of cells - as they approach surface, cells die and their cytoplasm is replaced by keratin
20
Q
Describe keratin
A
Tough, water-proof material that provides cells in the outer layer of the skin with an abrasion resistant and protective quality
21
Q
______ is the outermost layer of the epidermis, also known as the horny layer
A
Stratum corneum
22
Q
What are the 5 layers of the epidermis from the outermost down?
A
- Stratum corneum (horney layer) - thick, dead, keratin-filled cells (layer that sheds)
- Stratum lucidum - only present in thick, hairless skin (e.g. palms)
- Stratum granulosum - where cell first becomes full of keratin
- Stratum spinosum
- Stratum germintativum (stratum basal) - epithelial cells constantly dividing
23
Q
______ produce melanin and are stimulated by the sun
A
Melanocytes
24
Q
We have a totally new epidermis every _________
A
24-45 days
25
Describe skin pigment
1. Gives skin colour
2. Produced in stratum germintativum by melanocytes
3. Pigment is called melanin (brown/dark) - primary function to absorb harmful UV radiation from sunlight
26
Describe the dermal - epidermal junction
1. Specialized area between epidermis and dermis
2. Like glue holding the two layers together
3. Blisters caused by breakdown of this junction
27
Describe the dermis
1. Deeper and thicker than epidermis
2. Composed largely of connective tissue
3. Cells scattered further apart than epidermis and there are many fibres (collagen and elastic) between cells
28
What does the dermis contain?
1. Nerve endings
2. Muscle fibres
3. Hair follicles
Sweat and sebaceous glands
4. Blood vessels
29
What are the 2 distinct layers of the dermis?
1. Papillary layer (superficial layer) - parallel rows of dermal papillae, helps bind dermis to epidermis, basis of fingerprinting, improves our grip
2. Reticular layer (deepest layer) - network of collagenous & stretchable fibres, number of elastic fibres decreases with age (wrinkles)
30
Describe the hypodermis (subcutaneous tissue)
1. It is NOT a part or layer of the skin 🚫
2. Lies deeply into the dermis
3. Forms a connection between the skin and underlying structures (muscle and bone )
31
________ is the process of inserting a hollow tube into the subcutaneous tissue (hypodermis) and removing fat with a vacuum aspirator
Liposuction
32
What do you need to understand about hair?
1. Human body covered in millions of hairs
2. At the time of birth, most of the follicles required for hair growth are present
3. Hairless areas include lips, palms, soles of feet
33
________ is the hair of newborns, means down in Latin, and is soon replaced with stronger and more pigmented hair
Lanugo
34
Describe hair growth
1. Requires an epidermal tube-like structure called a hair follicle (developed by epidermal cells growing down into the dermal layer)
2. Growth begins from small cap-shaped clusters of cells at the base of the follicles called hair papilla
3. Hair root lies inside the follicle
35
The visible part of the hair is called the _______, and most hair is _______
Shaft; invisible
36
_________ is specialized smooth muscle attached to the base of dermal papillae and contract to cause goosebumps/ hair standing on ends
Arrector pili
37
What do you need to understand about skin receptors?
1. They are specialized nerve endings that make it possible for skin to act as a sense organ
2. They relay messaged to the brain of touch, pain, temp, and pressure
38
________ skin receptors detect light touch (generally superficial)
Meissner's (tactile) corpuscles
39
_______ skin receptors detect pressure (generally deeper)
Pacini (lamellar) corpuscles
40
_________ skin receptors detect low frequency vibration and fine touch
Krause end bulbs (bulboid corpuscles)
41
_______ nerve endings detect pain
Free
42
What do you need to understand about nails?
1. Produced by epidermal cells over ends of fingers and toes (when cells fill with keratin)
2. Visible part called nail body
3. Root lies in. Groove and is hidden by cuticle
4. Crescent shaped area near root is called lunula
5. Nail bed can change colour with blood flow
43
The ______ is the crescent shaped area near the root of the nail
Lunula
44
Skin/cutaneous glands (all exocrine) can be divided into _______ and _______
1. Sudoriferous glands (sweat)
2. Sebaceous glands (oil)
45
Sudoriferous glands (sweat) can be divided into ________ and _______
1. Eccrine
2. Apocrine
46
Describe eccrine glands
1. Function throughout life
2. Most numerous, important, and widespread sweat glands
3. Produce sweat, which is eliminated through pores
4. Assist in body heat regulation
47
Describe apocrine glands
1. Enlarge at onset of puberty
2. Mostly in armpit and around genitals
3. Secretion is thicker/milky
4. Odor is caused by bacterial breakdown
48
Describe sebaceous glands
1. Grow where hair grows
2. Secrete oil (sebum) for hair and skin (ducts open into hair follicles
3. Level of secretion increases in adolescence
4. Amount of secretion regulated by sex hormones
5. Sebum in sebaceous gland duct may darken into blackhead
6. Secretion decreases with age
49
What causes skin cancer?
Causes may be genetic and/or environmental (e.g. sun exposure)
50
What are the 3 most common types of skin cancer?
1. Squamous cell carcinoma
2. Basal cell carcinoma
3. Malignant melanoma
51
Describe squamous cell carcinoma
1. Slow growing
2. Malignant tumor of epidermis
3. First appear as hard, raised nodules
4. If left untreated, it will grow and metastasize
52
Describe Basal cell carcinoma
1. Most common type of skin cancer
2. Usually on upper face
3. Least likely to metastasize
4. Small raised lesion
5. Erodes in the centre, forming a bleeding, crusted crater
53
Describe malignant melanoma
1. Most serious form of skin cancer
2. Can develop from a benign pigmented mole
3. Develops into a dark, spreading, cancerous lesion
4. Risk is significantly higher if you have 2 blistering sunburns before 20
54
What are the warning signs of malignant melanoma (A, B, C, D, E)
1. Asymmetry (one side bigger than other)
2. Border (irregular)
3. Colour (uneven)
4. Diameter (>6mm)
5. Evolving
55
What are the 5 most important functions of skin?
1. Protection
2. Temperature regulation
3. Sensation
4. Excretion
5. Synthesis of vitamin D
56
What are the steps of skin repair?
1. Blood clots, quickly stopping blood loss
2. Germintativum cells grow laterally to close gap and restore epidermis
3. Fiber-producing cells in dermis repair damaged network of fibers
4. Clot dissolves, leaving repaired epidermis and thickened dermis
57
________ and _______ are important contributors to the skin being the body's first line of defense
1. Keratin (horny layer) - infections by microbes, harmful chemicals, cuts and tears, excessive fluid loss
2. Melanin - UV rays
58
The skin's mechanisms of temperature regulation involve ______ which has a cooling effect
Heat loss through evaporation
59
How does the body cool?
1. Regulation of sweat secretion - heat loss through evaporation
2. Regulation of blood flow near skin's surface - head loss through radiation
60
Describe the skin's role as a sense organ
Receptors serve as receivers for the body, keeping it informed of changes in the environment (e.g. touch, pressure, 🔥, ❄️)
61
The body can lose substances through the skin via sweat. For example ____, _____, and _____
1. Salts
2. Waste products
3. Hormones
62
Describe the skin's role in vitamin D synthesis
1. Initiated when sun exposed to UV
2. Series of reactions involving the liver, kidneys resulting in the active form of vitamin D
3. Most North Americans are deficient
63
______ is one of the most serious and frequent problems affecting the skin
1. Burns
64
Causes of burns include _____
1. Sun
2. Chemicals/ acids
3. Electricity
4. Friction
65
The treatment and recovery or survival of burns depends on _____
1. Total area involved
2. Severity or depth of burns
(Rule of nines in adults - surface area estimation)
66
What is the rule of nines?
1. Estimates the percent of body burned
2. Body surface area divided into 11 areas of 9% each
3. Additional 1% at genitals
4. Intended for rapid assessment
67
Describe first degree (superficial partial-thickness) burns
1. Involves only the surface layer of epidermis
2. Minimal damage (e.g. peeling and blistering)
68
Describe second degree (partial-thickness) burns
1. Involve the deep epidermal layers
2. Always cause injury to upper layers of dermis
3. Severe pain, swelling, blisters, scarring
69
Describe third degree (full-thickness) burns
1. Complete destruction of the epidermis and dermis
2. May involve underlying muscle and bone
3. No pain initially; intense pain follows
4. Serious fluid loss and increased risk of infection
70
Describe fourth degree (full-thickness) burns
1. Muscle and bone involved
2. May require extensive grafting (or amputation)
3. High voltage electrical burns
4. Exposure to extreme heat
