a&p exam 1
selective permeability
a barrier that allows some substances to pass through it while excluding others
transverse section
a cut along a horizontal plane, dividing the body into superior and inferior parts (cross section_
tight junction
impermeable junction that encircles the cells and binds them together
neuron
nerve cells that receive and conduct electrochemical impulses from one part of the body to another
visceral layer
part of serous membrane that covers the outside of organs in a cavity
microtubule
part of the cytoskeleton that determines the overall shape of a cell and the distribution of its organelles
intermediate filament
part of the cytoskeleton that helps form desmosomes and provides internal wires that resist pulling forces on the cell
microfilament
part of the cytoskeleton that is most involved in cell motility and shape changes
extracellular matrix
produced by connective tissue that is composed of a structureless ground substance and fibers
secretion
product that usually contains proteins molecules in an aqueous fluid
fibrosis
repair by dense connective tissue (formation of scar tissue)
tRNA
small RNA molecules that escort amino acids to the ribosome
simple diffusion
unassisted diffusion of solutes through the plasma membrane
vesicular transport
uses ATP to fuse or separate membrane vesicles and cell membranes
hyperplasia
enlargement of certain body tissues due to some irritant or condition that stimulates the cells
endocytosis
ATP-requiring process that takes up/engulfs extracellular substances into the cell
triplet
a three-base sequence of DNA
elastic cartilage
cartilage found in structures with elasticity
ventral body cavity
cavity that contains all structures within the chest and abdomen
dorsal body cavity
cavity that contains two subdivisions on the posterior side of the body
reticular layer
deepest skin layer that contains dense irregular connective tissue, blood vessels, sweat/oil glands, and pressure receptors
cardiovascular system
delivers nutrients, oxygen, hormones, and other substances to (and picks up wastes such as CO2) from cells near exchange sites (does this through blood)
keratin
fibrous protein that makes a tough protective layer of the epidermis
effector
flows control center's response back to stimulus
cardiac muscle
found in the heart wall and contracts to make the heart pump and propel blood (involuntarily)
stratified epithelium
more than one layer of epithelial cells
mRNA
RNA that carries instructions for protein synthesis from DNA in the nucleus to the ribosomes in the cytoplasm
rRNA
RNA that helps form ribosomes where proteins are synthesized
gene
a DNA segment that carries the information for building a protein
frontal (coronal) section
a cut along the lengthwise plane that divides the body into anterior and posterior parts
sagittal section
a cut along the lengthwise plane that divides the body into left and right parts
nuclear envelope/membrane
a double membrane barrier surrounding the nucleus (its boundary)
hair
a flexible epithelial structure that can be divided into hair root and hair shaft
plasma membrane
a fragile, transparent barrier that contains the cell contents and separates them from the surroundings
organ system
a group of organs that work together to accomplish a common purpose
transitional epithelium
a highly modified, stratified squamous epithelium that forms the lining of the urinary bladder, ureters, and part of the urethra
simple columnar epithelium
a single layer of tall cells that fit closely together
simple squamous epithelium
a single layer of thin squamous cells resting on the basement membrane (thin, scale-like)
organ
a structure composed of two or more tissue types that performs a specific function for the body
responsiveness/irritability
ability to sense changes (stimuli) in the environment and then react to them
movement
all activities promoted by the muscular system
metabolism
all chemical reactions that occur within the body and all of its cells
neoplasm
an abnormal mass of proliferating cells (can be cancerous)
adipose tissue
an areolar tissue in which adipose cells are most prominent (fat)
desmosome
anchoring junction that prevents cells from getting pulled apart
enzyme
biological catalyst that speeds up every chemical reaction that occurs in the cell
dermis
bottom layer of the cutaneous membrane composed mostly of dense (fibrous) connective tissue
pinocytosis
cell engulfing droplets of extracellular fluid ("gulping/drinking")
epidermal dendritic cell
cell scattered about in the epidermis that alerts and activates the immune system cells
receptor-mediated endocytosis
cell taking up specific target molecules
goblet cells
cells that produces a lubricating mucus (in epithelial membranes)
cytoplasm
cellular material outside the nucleus and inside the plasma membrane
mediastinum
central region that separates lungs into right and left cavities in thoracic (where heart and trachea are found)
inclusions
chemical substances that may be present in cytosol depending on the cell type
chromosome
coiled and condensed chromatin threads formed when a cell is dividing
chromatin
collection of DNA-wrapped histones when a cell is not dividing
lymphatic system
complements the cardiovascular system by returning leaked fluids to the bloodstream to keep blood circulating through the body
mucous membrane
composed of epithelium resting on a loose connective tissue membrane (lamina propia); lines all body cavities open to the exterior (WET)
bone
composed of osteocytes in cavities (lacunae) surrounded by layers of a very hard matrix of calcium salts and collagen fibers
hair follicle
compound structures consisting of epithelial and connective tissue to form hair
cartilage
connective tissue composed of chondrocytes that is less hard and more flexible than bone
blood (vascular tissue)
connective tissue consisting of blood cells surrounded by blood plasma (nonliving, fluid matrix)
synovial membrane
connective tissue membrane composed of loose areolar connective tissue and contains epithelial cells
reticular connective tissue
connective tissue that consists of a delicate network interwoven reticular fibers
loose connective tissue
connective tissue that is softer with more cells and fewer fibers
dense connective/fibrous tissue
connective tissue with collagen fibers forming the main matrix, fibroblasts rows between fibers
skeletal system
consists of bones, cartilages, and joints that support the body and provide a framework for skeletal muscles
gland
consists of one or more cells that make a secrete a specific product
skeletal muscle
consists of skeletal muscle tissue packaged by connective tissue sheets to form the organs (forms flesh of the body and can be moved voluntarily)
nutrients
contain chemicals used for energy and cell building
pelvic cavity
contains reproductive organs, bladder, and rectum
abdominal cavity
contains stomach, liver, and intestines
nucleus
control center of a cell usually found in the center and houses the cell's DNA
endocrine system
controls body activities at a much slower pace than the nervous system; secretes hormones which regulated other structures
body membrane
covers surfaces, lines body cavities, and forms protective sheets around organs
section
cut made in a body to look at internal structures
skin
cutaneous membrane that is absolutely essential in keeping water and precious molecules in the body while keeping excess water out
atrophy
decrease in size of organ/body area due to loss of normal simulation
stratum basale
deepest cell layer of epidermis which contains stem cells
tendons
dense connective tissue that attaches skeletal muscles to bones
ligament
dense connective tissue that connects bones to bones at joints
control center
determines the level at which a variable maintains
endocrine glands
develops from endocrine sheets that lose their ducts and secrete directly into blood vessels (secrete hormones)
exocrine glands
develops from endocrine sheets that retain their ducts and secrete to the epithelial surface (secretes sweat and oil)
facilitated diffusion
diffusion of needed substances that are both lipid-insoluble and too large to pass through pores, substances can also be charged
osmosis
diffusion of water through a selectively permeable membrane
homeostatic imbalance
disturbance of homeostasis, can cause or be a result of disease
cytokinesis
division of the cytoplasm that begins in late anaphase and finishes in telophase
serous membrane (serosa)
epithelial membrane composed of a layer of simple squamous resting on a thin layer of areolar connective tissue
cutaneous membrane
epithelial membrane composed of two layers (epidermis, dermis) and is exposed to air/makes up the surface of the body (DRY)
stratified columnar epithelium
epithelium that consists of multiple layers where topmost layer is column-shaped
stratified cuboidal epithelium
epithelium that consists of multiple layers where topmost layer is cube-shaped
directional terms
explains exactly where one body structure is in relation to another
spinal cavity
extends from the cranial cavity to end of the spinal cord, protected by bony vertebrae (make up the spine)
extracellular (interstitial) fluid
fluid that continuously bathes the exterior of our cells (contains nutrients, gases, salts, amino acids, sugars, fatty acids, vitamins)
epithelial membrane
functions as a covering and lining, and contains an epithelial layer that is combined with a different connective tissue layer
intercalated discs
gap junctions where cardiac cells fit together and can send ions freely between cells
tissue
group of cells that are similar in structure and function
organism
highest level of structural organization
fibrocartilage
highly compressible cartilage that forms discs between vertebrae of the spinal column (for cushioning)
negative feedback
homeostatic control mechanism whose response to stimulus is to shut it off or lessen the intensity
positive feedback
homeostatic control mechanisms whose response is to increase the stimulus and push the variable further from its original state (UNCOMMON)
solution
homogeneous mixture of 2 or more components (present on both sides of the plasma membrane)
skin appendage
includes cutaneous glands, hair/follicles, and nails that all arise from the epidermis to help maintain homeostasis
stroma
internal framework of an organ (formed by reticular connective tissue)
gap junction
junction used mainly for communication
respiratory system
keeps the body supplied with oxygen and removes carbon dioxide
phagocytosis
larger substances being engulfed ("cell eating")
stratum lucidum
layer above granulosum only present in areas of the body with no hair (thick, clear layer)
stratum spinosum
layer above the basale in the epidermis that contains thick bundles of intermediate filaments
stratum granulosum
layer above the spinosum where cells are flattened, organelles deteriorate, and the cells are flattened
flagella
longer projection from the cell that is used to propel
translation
mRNA converted to its amino acid sequence
codon
mRNA sequence that corresponds to DNA's triplet
ribosome
made of proteins and rRNA, site of protein synthesis
exocytosis
mechanism used to actively secrete hormones, mucus, and eject cellular waste
lysosome
membranous bag containing powerful digestive enzymes
peroxisome
membranous sac containing oxidase enzymes that use oxygen to detoxify harmful or poisonous substances
keratinocyte
most common cell type in the epidermis that produces keratin
stratified squamous epithelium
most common stratified, usually has many cell layers with topmost layer having a thin, scalelike shape
areolar connective tissue
most widely distributed connective tissue variety that is soft and pliable and cushions and protects the organs (acts as the glue of the body)
hyaline cartilage
most widespread cartilage that is composed of collagen fibers hidden under a rubbery matrix
smooth (visceral) muscle
muscle tissue found in the walls of hollow organs, contracts and enlarges to accommodate substances (no striations)
muscular system
muscles whose only function is to contract for movement
cytoskeleton
network of protein structures throughout the cytoplasm that determines cell shape, supports organelles, and provides machinery for transport and movement
simple cuboidal epithelium
one layer of cuboidal cells resting on a basement membrane
simple epithelium
one layer of epithelial cells
nuclear pore
opening in nuclear envelope that allows selected substances to pass through
Golgi apparatus
organelle found near the ER and works to modify, package, and ship proteins in specific ways depending on its destination (these proteins are received from the ER)
mitochondria
organelle that houses reactions in which oxygen is used to break down foods and captures the resulting energy in ATP molecules
centriole
organelle that lies close to the nucleus; generates microtubules and directs mitotic spindle formation during cell division
reproductive system
organs that work to produce offspring
stratum corneum
outermost epidermal layer that is 20-30 cells thick and contains dead cells filled with keratin
parietal layer
part of serous membrane that lines a specific portion of the wall of the ventral cavity
cell division
period in which a cell reproduces itself
interphase
period in which the cell grows and carries on its usual metabolic activities
melanin
pigment ranging from yellow to brown to black that is produced by melanocytes found in the stratum basale layer
diffusion
process by which molecules move away from areas where they are more concentrated to areas where they are less concentrated (moves down a concentration gradient)
active transport
process by which substances are transported against the gradient through the use of protein carriers powered by ATP
filtration
process by which water and solutes are forced through a membrane by fluid pressure (occurs when there is a pressure gradient)
transcription
process in which DNA is encoded into an RNA message
digestion
process of breaking down ingested food into simple molecules that can be absorbed
excretion
process of removing excreta (wastes) from the body
reproduction
production of offspring (cellular or organismal)
urinary system
removes nitrogen-containing waste from blood and flushes it from the body through urine
regeneration
replacement of destroyed tissue by the same type of cells
edema
result of areolar tissue soaking up fluids and wastes inflamed regions (more fluid present than normal)
secretory vesicles
sac filled with protein that pinches off of Golgi and travels to the plasma membrane (to fuse and release substances outside of cell)
nail
scalelike modification of the epidermis
rough endoplasmic reticulum
segment of the ER that is studded with ribosomes that work as the cell's membrane factory
smooth endoplasmic reticulum
segment of the ER that metabolizes lipids and detoxifies drugs and pesticides
cytosol
semitransparent fluid that suspends other elements
thoracic cavity
separated from rest of ventral body by the diaphragm, contains heart and lungs (protected by ribcage)
peritoneum
serosa lining the abdominal cavity and its organs
pericardia
serosa surrounding the heart
pleurae
serosa surrounding the lungs
metaphase
short stage in which chromosomes line up in a straight line
pseudostratified columnar epithelium
single layer of cells on the basement membrane that have different heights (appear stratified)
nucleolus
site where ribosomes are assembled before they leave to work on protein synthesis
arrector pili
small bands of smooth muscle cells that connect each side of the hair follicle to the dermal tissue
cells
smallest units of life that are formed by molecules associating in specific ways
intracellular fluid
solution contained small amounts of gases, nutrients, and salts dissolved in water (found on the inside of a cell: cytosol)
cranial caivty
space inside bony skull
neuroglia
special group of supporting cells that insulate, support, and protect neurons
organelle
specialized cellular compartments that are the metabolic machinery of the cell
anaphase
stage in which centromeres split and and chromatids move apart towards opposite sides of the cell
prophase
stage in which chromatin shortens to form (sister) chromatids that are held together by a centromere which are then connected to microtubules (mitotic spindle) in preparation for separation
telophase
stage in which chromosomes uncoil (forms chromatin again) and a nuclear envelope forms around each chromatin mass
anatomical position
standing up with feet parallel and arms hanging at sides with palms facing forward/anterior
cell
structural unit of all living things
hypodermis
subcutaneous tissue that is not part of the skin but helps anchor it to the underlying organs
solvent
substance present in largest amount in a solution
solute
substance present in smallest amount in a solution
apocrine gland
sudoriferous gland that is larger than eccrine glands and secretes fatty acids and proteins into hair follicles
eccrine gland
sudoriferous gland that produces sweat to regulate body temperature
papillary layer
superficial dermis region that is uneven and has projections; brings nutrients to the epidermis and increase friction on hands and feet
endoplasmic reticulum
system of fluid-filled tunnels throughout the cytoplasm that acts as a network of channels for carrying things from one place to another in the cell
homeostasis
the body's ability to maintain relatively stable internal conditions with continuously changing external conditions
nervous system
the body's fast-acting control system that includes the brain, spinal cord, nerves, and sensory receptors
integumentary system
the external covering of the body including skin, hair, and nails (protects organs and regulated temp)
epithelial tissue (epithelium)
the lining, covering, and glandular tissue of the body; covers all free body surfaces inside and out, and contains versatile cells
mitosis
the process of dividing a nucleus into two daughter nuclei with exactly the same genes as the mother nucleus
cell life cycle
the series of changes a cell goes through from the time it's formed until it divides
physiology
the study of how the body and its parts work or function
anatomy
the study of the structure and shape of the body and its parts and their relationships to one another
atoms
tiny building blocks of matter that can combine to form molecules
microvilli
tiny, fingerlike extensions from the plasma membrane that increase the cell's surface area (more surface area = more substances in and out at quicker rates)
burn
tissue damage and cell death caused by intense heat, electricity, radiation, or chemicals
connective tissue
tissue that connects body parts; primarily involved in protecting, supporting, and binding together other body tissues
muscle tissue
tissue that is highly specialized to contract/shorten and generates the force required to produce movement
epidermis
top layer of the cutaneous membrane that is composed of stratified squamous
digestive system
tube running from mouth to anus that contains organs that break down food and deliver resulting nutrients to the blood for dispersal
receptor
type of sensor that monitors and responds to environmental changes
generalized cell
unspecialized cell with the same basic parts and functions common to all cells
matrix
well-nourished stratum basale where hair is formed
cilia
whiplike extensions that move substances along the cell surface ("crowdsurfing")