3: Tissues and the Integumentary System
- Page ID
- 127090
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\( \newcommand{\dsum}{\displaystyle\sum\limits} \)
\( \newcommand{\dint}{\displaystyle\int\limits} \)
\( \newcommand{\dlim}{\displaystyle\lim\limits} \)
\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)
( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\id}{\mathrm{id}}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\kernel}{\mathrm{null}\,}\)
\( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\)
\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\)
\( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)
\( \newcommand{\vectorA}[1]{\vec{#1}} % arrow\)
\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow\)
\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vectorC}[1]{\textbf{#1}} \)
\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)
\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)
\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\(\newcommand{\longvect}{\overrightarrow}\)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- 3.1: Introduction to Tissues
- Tissues are groups of similar cells organized to perform specific functions. The four basic tissue types provide the structural and functional foundation of organs and help explain both normal body function and disease.
- 3.2: Epithelial Tissue — Covers and Communicates
- Epithelial tissue functions as a protective and regulatory barrier, controlling what enters and leaves the body, and it also contributes to sensation. Differences in cell shape and layering create specialized epithelial tissues adapted for specific roles on body surfaces and within organs.
- 3.3: Connective Tissue — Supports and Protects
- Connective tissue links, supports, protects, and transports throughout the body using cells embedded in an extracellular matrix. Differences in matrix composition create connective tissue proper, supportive tissues like cartilage and bone, and fluid tissues such as blood and lymph, each specialized for distinct functions.
- 3.4: Muscle Tissue — Built to Move
- Muscle tissue is specialized for contraction, allowing the body to move, maintain posture, generate heat, and propel substances such as blood and food. Differences in control, structure, and location divide muscle tissue into three distinct types, each adapted to perform specific roles.
- 3.5: Nervous Tissue — Perceives and Responds
- Nervous tissue is characterized as being excitable and capable of sending and receiving electrochemical signals that provide the body with information. Two main classes of cells make up nervous tissue: the neuron and neuroglia. Neurons propagate information via electrochemical impulses, called action potentials, which are biochemically linked to the release of chemical signals. Neuroglia play an essential role in supporting neurons and modulating their information propagation.
- 3.6: Epithelial Membranes
- Epithelial membranes form the protective linings, coverings, and interfaces between the body and its internal and external environments. Differences in structure and location give rise to mucous, serous, and cutaneous membranes, each in specific regions of the body and specialized for either protection, secretion, absorption, or friction reduction.
- 3.7: Tissue Repair and Wound Healing
- Wound healing is a coordinated, multi-phase process that restores tissue integrity after injury by stopping bleeding, preventing infection, rebuilding damaged structures, and strengthening the repaired area. The four overlapping phases of wound healing explain why healing takes time, why scars form, and what happens when the process is disrupted.
- 3.8: Overview of Cancer
- Cancer develops when normal controls on cell growth and division break down, allowing cells to multiply uncontrollably and disrupt normal tissue structure. Understanding how cancer alters cell behavior helps explain how tumors form, spread, and interfere with normal organ function.
- 3.9: Introduction to the Integumentary System
- The integumentary system includes the skin and its accessory structures, working together to protect the body, regulate temperature, provide sensation, and support vitamin D production.
- 3.10: Structure of the Skin — Epidermis
- The epidermis is the skin’s outer protective layer, designed to shield the body from dehydration, injury, and invading microorganisms. Its layered organization supports these essential protective functions.
- 3.11: Melanin and Skin Color
- Melanin is a pigment produced by specialized skin cells that plays a key role in determining skin color and protecting the body from ultraviolet (UV) radiation. Differences in melanin production, distribution, and type explain normal variation in skin color and how the skin responds to sunlight.
- 3.12: Structure of the Skin — Dermis and Hypodermis
- Beneath the epidermis, the dermis and hypodermis provide the skin with strength, flexibility, nourishment, and support. Together, these layers house blood vessels, nerves, glands, and fat that allow the skin to protect the body, sense the environment, regulate temperature, and absorb physical stress.
- 3.13: Sweat and Sebaceous Glands
- Sweat and sebaceous glands are specialized skin glands that help regulate body temperature, protect the skin, and maintain moisture. Understanding how these glands work helps explain sweating, body odor, and common skin conditions like oily skin and acne.
- 3.16: Burns
- Burns are injuries that damage the skin and underlying tissues, disrupting the body’s protective barrier and normal homeostasis. The depth and extent of a burn determine its severity, treatment needs, and potential complications such as fluid loss, infection, and impaired healing.
- 3.17: Skin Cancer
- Skin cancer develops when mutations disrupt normal cell growth in the epidermis, allowing abnormal cells to divide uncontrollably. Basal cell carcinoma, squamous cell carcinoma, and melanoma differ in their cells of origin, behavior, and potential to spread.
- 3.18: Acne
- Acne is a common skin condition that develops when hair follicles become clogged with sebum, the keratin of dead skin cells, and bacteria, leading to inflammation. Hormonal changes, bacterial growth, and immune responses together shape the severity of acne and the types of lesions that form.