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anatomy

study of the structure of the body

gross anatomy

study of the macroscopic structures of an organism

microscopic anatomy

study of the microscopic structures of an organism

physiology

study of the functions of an organism and its parts

irritability

ability to sense changes in the environment and respond to them

digestion

breaking down of ingested foodstuffs to simple molecules that can be absorbed into the blood

metabolism

taking the small things that are broken down by digestion and using them

excretion

getting rid of wastes

reproduction

at the cellular level, the original cell divides, producing two identical daughter cells that may then be used for body growth or repair

growth

an increase in the size of a body part or an organism

homeostasis

state of equilibrium in the body with respect to its functions, chemical levels, and tissues

receptor

monitors the body's variables like blood pressure

control center

determines the set point, which is the level or range at which a variable is to be maintained

effector

structure in the body that can change the value of a variable

negative feedback mechanisms

when the effect of response to stimulus is to shut off the original stimulus or reduce its intensity

positive feedback mechanisms

increases the original disturbance or stimulus by pushing the value further from the original value

homeostatic imbalance

disturbance of homeostasis or when negative feedback mechanisms are overwhelmed

anatomical position

standard body position (feet forward, eyes forward, palms up)

superior

toward the head or the upper part of the body or a structure

inferior

away from the head end or toward the lower part of the structure

anterior

toward the front of the body

posterior

toward the back of the body

medial

toward or at the midline of the body

lateral

away from the midline of the body

intermediate

between a more medial and a more lateral structure

proximal

closer to the origin of the body part (the point of attachment of a limb to the body trunk)

distal

father from the origin of the body part (the point of attachment of a limb to the body trunk)

superficial

toward or at the body surface

deep

away from the body surface

axial

makes up the main axis of the body and includes the head, neck, and trunk

appendicular

consists of the appendages, or limbs, which are attached to the body's axis

plane

flat surface of a portion that that the body is cut into

sagittal plane

vertical plane that divides the body into right and left parts

midsagittal plane

sagittal plane that lies exactly in the midline

frontal plane

lies vertically and divides the body into anterior and posterior parts

transverse plane

runs horizontally from right to left, dividing the body into anterior and posterior parts

viscera

internal organs

thoracic cavity

superior subdivision surrounded by ribs and muscles

pleural cavities

two subdivisions of the thoracic cavity, each enveloping a lung

mediastinum

medial cavity of the thorax that contains the heart, the trachea, and great vessels

pericardial cavity

encloses the heart and surrounds the remaining thoracic organs

abdominal cavity

contains the stomach, intestines, spleen, liver, and other organs

serous membrane

moist membrane found in the closed ventral body cavities

oral cavity

contains the teeth and the tongue; continuous with the digestive organs

nasal cavity

part of the respiratory system passageways

orbital cavity

home to the eyes, which it houses in the anterior position

middle ear cavity

contain tiny bones that transmit sound vibrations to the hearing receptors in the inner ears

synovial cavity

secretes a lubricating fluid that reduces friction as the bones move across one another

squamous epithelium

flat cells

cuboidal epithelium

cube shaped cells

columnar epithelium

tall cells (like a column)

simple epithelium

one cell layer thick

stratified epithelium

made up of several cell layers

pseudostratified epithelium

stratified "wanna-be"; looks like several layers, but it is only one layer

endocrine gland

produce hormone and eventually lose their ducts

exocrine gland

secrete their onto body surfaces (skin) or into body cavities

hormones

regulatory chemicals that endocrine glands secrete by exocytosis directly into the extra cellular space

collagen fibers

most abundant of the three fibers found in the matrix of connective tissue

fibroblasts

continuously manufacture the fibers and scant ground substance

connective tissue proper

has fibers as its prominent element

loose connective tissue

category of connective tissue that includes areolar tissue, reticular tissue, and adipose tissue; most common type of connective tissue in vertebrates; holds organs in place and attaches epithelial tissue to other underlying tissues; surrounds the blood vessels and nerves

adipose tissue

areolar connective tissue modified to store nutrients; a connective tissue consisting chiefly of fat cells

reticular connective tissue

connective tissue with a fine network of reticular fibers that from the internal supporting framework of lymphoid organs

dense regular tissue

contains closely packed bundles of collagen fibers running in the same direction

dense irregular tissue

has the same structural elements as the regular variety, but the bundles of collagen fibers are much thicker and are arranged irregularly; forms sheets in body areas where tension is exerted from many different directions

cartilage

has qualities intermediate between dense connective tissue and bone; tough but flexible; lacks nerve fibers and is avascular; receives its nutrients by diffusion from blood vessels located in the connective tissue membrane surrounding it

hyaline cartilage

most abundant cartilage type in the body; provides firm support with some pliability, covering the ends of long bones as articular cartilage and providing springy pads that absorb compression as joints

elastic cartilage

forms the "skeletons" of the external ear and the epiglottis

fibrocartilage

perfect structural intermediate between hyaline cartilage and dense regular connective tissues; has rows of chondrocytes alternating with rows of thick collagen fibers; found where strong support and the ability to withstand heavy pressure and required

bone

has a rocklike hardness that gives it the exceptional ability to support and protect body structures; bones provide cavities for fat storage and synthesis of blood cells

osseous tissue

another word for bone

blood

the fluid within blood vessels; the most atypical connective tissue; does not connect things or give mechanical support; develops from mesenchyme and consists of blood cells, surrounded by a nonliving fluid matrix called blood plasma

neurons

highly specialized nerve cells tat generate and conduct nerve impulses

muscle tissue

highly cellular, well-vascularized tissue that is responsible for most types of body movement

skeletal muscle

packaged by connective tissue sheets into organs called skeletal muscles that are attached to the bones of the skeleton

smooth muscle

cells of these muscles do not have any visible striations; spindle shaped and contain one centrally located nucleus; found mainly in the walls of hollows organs over than the heart; acts to squeeze substances through these organs by alternately contracting and relaxing

cardiac muscle

found only in the walls of the heart; its contractions help propel blood through the blood vessels to all parts of the body

voluntary muscle

muscle under strict nervous control, such as skeletal muscle

involuntary muscle

muscle that cannot ordinarily be controlled voluntarily

cutaneous membrane

cutaneous membranes of the skin cover the surface of the body; consist of stratified squamous epithelium and the underlying connective tissues; cutaneous membranes are thick, relatively waterproof, and dry

mucous membranes

membranes that form the linings of body cavities open to the exterior (digestive, reparatory, urinary, and reproductive tracts)

serous membranes

moist membranes found in closed ventral body cavities; consists of simple squamous epithelium resting on a thin layer of loose connective tissue

integumentary system

the skin as an entire organ system; provides the external protective covering of the body

hypodermis

loose connective tissue beneath the dermis and connects the dermis to muscle or bone; subcutaneous tissue just deep to the skin and consists of adipose plus some areolar connective tissue

epidermis

superficial layer of the skin; composed of keratinized stratified squamous epithelium

keratin

most abundant protein in dead epidermal structures such as hair and nails; waterproofing protein produced by the epidermis; fibrous protein that helps give the epidermis its protective properties

melanin

dark brown pigment found in skin; formed by cells called melanocytes; imparts color to the skin and hair; polymer made of tyrosine amino acids

melanocytes

cells in the epidermis that produce melanin; found in the deepest layer of the epidermis

tactile cells

present at the epidermal-dermal junction and are shaped like a spiky hemisphere and is associated with a dislike sensory nerve ending

stratum basale

deepest epidermal layer; attached to the underlying dermis along a wavy borderline that reminds one of corrugated cardboard

stratum spinosum

several layers thick; these cells contain a weblike system of intermediate filaments, mainly tension-resisting bundles of pre-keratin filaments, which span their cytosol to attach to desmosomes

stratum granulose

consists of three to five cell layers in which keratinocyte appearance changes drastically, and the process of keratinization (in which cells fill with the protein keratin) begins

keratinization

when the cells fill with the protein keratin; the cells flatten, their nuclei and organelles begin to disintegrate and they accumulate two types of granules

stratum lucidum

layer of tissue found only in the palms of the hands and the soles of the feet

stratum corneum

broad zone twenty to thirty cell layers thick that accounts for up to three-quarters of the epidermal thickness

desquamation

when the dead cells flake off the skin from the top

dermis

the part of the skin that is not made up of epithelial tissue; second major skin region; strong, flexible connective tissue

papillary layer

areolar connective tissue in which fine interlacing collagen and elastic fibers form a loosely woven mat tat is heavily invested with small blood vessels

dermal papillae

peg-like projections that indent the overlapping epidermis

epidermal ridges

on the palms of the hands and the soles of the feet, dermal papillae lie atop larger mounds called dermal ridges, which in turn cause the overlying epidermis to form epidermal ridge; they increase friction and enhance the gripping ability of the finger and feet

reticular layer

accounts for about eighty percent of the thickness of the dermis; coarse, irregularity arranged, dense fibrous connective tissue

carotene

yellow to orange pigment found in certain plant products such as carrots lajfdskfjsadjfl

sweat glands

distributed over the entire skin surface except the nipples and parts of the external genitalia

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