TISSUE & INTEGUMENTARY SYSTEM

Anatomy

biological form of an organism

Physiology

biological functions an organism perform

Homeostasis

used to maintain a “steady state” or internal balance regardless of external environment

Set, point, stimulus, sensor, & response

Terms needed in the mechanisms of homeostasis

Negative Feedback

Type of feedback that helps variable return to a normal range ; example is body temperature

Positive Feedback

This type of feedback amplifies the stimulus and does not contribute to homeostasis ; example is oxytocin in childbirth

Circadian Rhythm

governs physiological changes that occur roughly every 24 hours

**Acclimatization**

A process in which homeostasis can adjust to changes in external environment ; its temporary (ajustment)

Thermoregulation

the process by which animals maintain an internal temperature

**Endothermic Animals**

they generate heat by metabolism; example are birds and mammals

Ectothermic Animals

they gain heat from external sources ; example are fish and amphibians

**Poikilotherm**

organisms that has body temperatures that varies with its environment ; temperature regulators

**Homeotherm**

organisms that has body temperatures that are constant ; temperature conformer

**Radiation, evaporation, convection, and conduction**

Four Physical Processes to exchange heat

Radiation

This Physical Process to exchange heat emits or releases electromagnetic waves

Evaporation

This Physical Process to exchange heat removes heat from the surface of liquid

Convection

This Physical Process to exchange heat transfers heat by movement of air or liquid

Conduction

This Physical Process to exchange heat transfers directly thermal motion or heat between molecules in contact w each other

Tissues

a group of cells or fluid that work together to perform a specific job in the body

Epithelial, Connective, Muscle, Nervous Tissues

Four Categories

Epithelial Tissue

This tissue covers the outside of the body and lines the organs and cavities within the body ; is closely packed with tight junctions

Tight Junction

Structures of the cell that will hold two cells together.

Apical Surface

the outer side / surface of the epithelial tissue

Basal Surface

inner surface of epithelial tissue

Squamous, Cuboidal, Columnar

Shapes of epithelial tissue

Simple, Stratified, Pseudostratified

Arrangements of epithelial tissue

Simple squamous epithelial tissue

This epithelial tissue allows transport across membranes ; it is in blood capillaries and lungs

Simple cuboidal epithelial tissue

This epithelial tissue has active secretory or absorptive functions ; it is in the kidney and salivary glands

Simple columnar epithelial tissue

This epithelial tissue maximizes absorption of nutrients and nourishment. ; it is in the intestinal tract

Stratified squamous epithelium

This type of epithelial tissue is adapted to skin’s mild mechanical abrasion and distortion ; it is mostly in the oral cavity, esophagus, and anal canal

Transitional Epithelium

Tissue that is under the stratified epithelium that is specialized to accommodate great stretching ; in the urinary tract and bladder

Connective Tissue

This tissue serves various binding and supportive function they mainly bind and support other tissues.

Collagenous fibers , Reticular fibers, Elastic Fibers

Fibers that connective tissue has

Collagenous fibers

Fiber to provide strength and flexibility \n

Reticular fibers

Fiber to join connective tissue to adjacent tissues

Elastic fibers

Fiber to stretch and snap back to their original length

Loose connective tissue & Dense connective tissue

The Two Types of Connective Tissue

Adipose, Blood, Cartilage, Bone

The Types of Specialized Connective Tissue

Loose (areolar) connective tissue

This connective tissue binds epithelia to underlying tissue and holds organs in place ; contains fibroblasts ; anchors blood vessels, nerves, and body organs

Fibroblasts

active cells responsible in producing **fibers** and **ground substance**.

Ground substance

amorphous gelatinous material

**Fibrocytes**

are inactive cells of the loose connective tissue

Fibrous (Dense) connective tissue

This type of connective tissue is found in tendons, which attach muscles to bones, and ligaments which connects bones at joints

Adipose Tissue

Special connective tissue that stores fat for insulation and fuel \n

Blood Tissue

Special connective tissue that is composed of blood cells and cell fragment

Cartilage Tissue

Special connective tissue that is a strong and flexible support material

Hyaline Cartilage

The most common type of cartilage in the cartilage tissue

Cartilage Tissue (2)

Special connective tissue that heals slowly due to lack of blood supply

Bone Tissue

Special connective tissue that is mineralized and forms the skeleton ; strongest connective tissue ; calcified matrix around collagen fiber

lacuna or lacunae

small pockets in the bone tissue

Osteocytes

Bone cells in the bone tissue ; they communicate with each other by the means of the canaliculi or the canaliculus (root looking).

Muscle Tissue

This type of tissue is the Most abundant ; Responsible for nearly all types of body movement ; consists of filaments of the proteins actin and myosin

Skeletal, Smooth and Cardiac Muscle

Type of Muscle Tissue

Skeletal Muscle

This type of muscle tissue is responsible for voluntary movement ; long cylindrical fibers which are multinucleated cells ; a striped or striated appearance

Cardiac Muscle

This type of muscle tissue is responsible for contraction of the heart ; cells here are short and are uninucleate ; branching network of fibers (tear-like) ; involuntary muscle

Smooth Muscle

This type of muscle tissue is responsible for involuntary body activities ; Long and tapering or spindle shape ; each cell has a single central nucleus ; Does not need signal from nervous system to move

Nervous Tissue

This type of tissue functions in the receipt, processing, and transmission of information ; reception of stimuli and conduction of impulses

Cell body or soma

The nucleus in the neurons

Axon

carries away signal from the cell toward the body cells or an effector organ ; often called nerve fiber

Neurons

Nerve cells that transmit nerve impulses ; Basic functional unit of the nervous system

Glial cells (Glia)

Support cells ; Helps nourish, insulate, and replenish neuron

Integumentary System

the body’s outer layer ; Includes the skin and all structures derived from or associated with skin

Mollusks

species that have a delicate epidermis that is why it needs a shell for protection.

Keratinocytes, Melanocytes, Langerhans, Merkel

Four type of cells in the integumentary system

Keratinocytes

(cells) deepest, produce keratin ; most common ; Provides protection and waterproofing ; Acts as sealant

Melanocytes

cells that makes dark skin pigment : melanin that absorbs UV light

Langerhans Cells

participate in immune responses against bacteria and viruses ; antigen presenting cells

Merkel Cells

cells that are associated with sensory nerve endings.

Epidermis & Dermis

Two layers of the integumentary system

Epidermis

Outer layer of the integumentary system

Stratum germinativum, stratum spinosum, stratum granulosum, stratum corneum

Layers of the epidermis (deep to superficial)

Stratum germinativum

Layer of epidermis that has the youngest cells ; replenishes the cells

Stratum Spinosum

layer of the epidermis that is responsible for skin strength and flexibility

Stratum granulosum

epidermis layer that has layers of flattened keratinocytes producing keratin (hair and nails made of it also)

Stratum corneum

epidermis layer that has the dead cells ; thick layers ; and is usually shed off in animals

Desmosomes

proteins that hold two cells together

Dermis

inner layer of the integumentary system

Papillary & Reticular

Two layers of the dermis

Hypodermis / Subcutaneous Tissue

Underneath the dermis is a connecting layer made up of loose connective tissue and adipose ; not considered as part of the skin

Arthropods

species that secretes a complex chitin ; their cuticle may remain tough but flexible

Decapod crustaceans

these species have cuticle stiffened by calcification (high production of calcium) \n

**sclerotization**

happens in insects ; process that produced the rigid cell of sclerotin that comprises an insect’s chitinous exoskeleton

Hair & Hair follicle, Nails & Sweat Glands

Skin Appendages that are Derived from epidermis but extended into dermis

Nail

Skin Appendages that have hard keratin and grows from the nail matrix

Hair & Hair follicles

Skin Appendages that provide warmth and protection (scalp) ; made out of hard keratin

Sweat Glands

Skin Appendages that covers the Entire skin surface except nipples and part of external genitalia ; prevents overheating

Eccrine & Apocrine

Two types of sweat gland

Eccrine gland

Sweat gland that produces thin watery secretion ; soles and palms

Apocrine gland

Sweat gland that produces thick odorous secretion ; axilla, eyelids, nipple and areola of breast, perianal region, and external genitalia

Melanin, Carotene, & Hemoglobin

Skin Color has three skin pigments

Melanin

Skin pigment that gives black or brown color of the skin ; most important

Carotene

Skin pigment that gives Yellow-orange pigment \n

Hemoglobin

Skin pigment that gives the pink color of skin