Anat 337 Exam 1

rostral

near or towards the nose

caudal

near or towards the tail

anatomical position

body standing upright, feet at shoulder width and parallel, toes forward, upper limbs are along each side and the palms of the hands face forward

neoplasia

abnormal cell proliferation

four tissues

epithelial, connective, muscle, nervous

functions of epithelial tissue

protection

selective permeability

diffusion

absorption (transcellular transport)

secretion

sensation

surface parallel transport

epithelial protection

body's first line of defense against chemical, physical, and biological wear and tear

epithelial selective permeability

epithelial cells act as gatekeepers allowing selective transfer of material

either diffusion or absorption/transcellular transport (processed to some degree before being released to blood or underlying tissue)

epithelial secretion

many epithelial cells produce and secrete specific chemicals onto their apical surface

epithelial sensation

specialized epithelial cells can detect light, taste, sound, smell, and hearing

epithelial surface parallel transport

transport of substances across the free surface of epithelium thanks to cilia

features of epithelial tissue

highly cellular, avascular, regeneration

cilia

extensions from apical surface of cell that beat in unison to move fluids as well as trapped particles across the surface in surface parallel transport

microvilli

extensions that serve to increase the surface area of the apical aspect of the cell for absorption; more surface area means more space for substances to contact the apical surface and be absorbed into cell for transcellular transport

simple squamous

single layer of flat, thin cells

allows materials to pass through quickly via simple diffusion

located in places we need substances to pass quickly, e.g. lung alveoli

simple cuboidal

single layer of cuboidal cells, may have microvilli

allows secretion and absorption

located to allow space for intracellular processing of absorbed substances and not overly-thick secretions, e.g. certain glands, kidney tubules

simple columnar

single layer of tall cells, may have microvilli

allows secretion and absorption

located to allow space for intracellular processing of absorbed substances, e.g. digestive tract

pseudostratified columnar

single layer of different size cells, only some reaching the surface, containing cilia on apical surface

allows surface parallel transport and secretion of mucous

located to move substances along the surface of the epithelium without smooth muscle, e.g. trachea

stratified squamous

multiple layers of flat cells

allows protection

located to provide more layers before damage reaches underlying tissue, e.g. skin, esophagus

transitional

special epithelium with layers of epithelial cells that stretch when the organ is distended

allows urinary organs to expand and stretch

located in bladder, ureters, urethra

gland

structure made up of one or more cells modified to synthesize and secrete chemical substances

endocrine gland

ductless gland that releases hormones directly into surrounding tissues and bloodstream

highly vascularized, can only affect target cells that have receptors for specific hormones, hormones have different effects on different target cells

hormonal secretions

happen in response to another hormone

neural secretions

happen in response to a nerve impulse

e.g. adrenal glands are stimulated by nerves to secrete epi/norepi

humoral secretions

happen in response to something in the blood

e.g. detecting low BGM means secreting glucagon to raise BGM

exocrine gland

secretions leave through a duct that opens directly or indirectly to a surface

e.g. skin, GI tract, respiratory tract

goblet cells

unicellular exocrine "gland" interspersed between columnar or pseudostratified columnar epithelial cells of mucous membranes; release mucin

basal lamina

superficial layer that restricts movement of proteins and other large molecules from underlying connective tissue into the epithelium

tight junctions

holds cells together so there is no extracellular space between them

prevents substances from moving between cells, thus forcing them to go through cells

allows epithelial to act as a selective barrier or gatekeeper

adhering junctions

acts like a belt holding the epithelial cells together for support and stability of tissue

desmosome

holds cells together like a push button on a jacket to provide support and stability of tissue

gap junction

forms an intercellular passageway between the membrane of adjacent cells to facilitate movement of small molecules and ions between the cytoplasm of adjacent cells

allows easy cell to cell communication

carcinoma

malignant tumor of epithelia

adenocarcinoma

malignant tumor of glandular epithelia

metaplasia

normal epithelia from one area is replaced by another form of epithelial not typical for that region

connective tissue

most diverse, common, and widely distributed tissue

functions of connective tissue

support

protection

defense

transport

energy storage

connective tissue protection

CT provides cushioning as well as bony projections of organs

connective tissue defense

specialized cells in CT defend the body from microorganisms that enter the body

connective tissue transport

transport of fluid, nutrients, waste, and chemical messengers is ensured by specialized fluid CT, such as blood and lymph

connective tissue energy storage

adipose cells store surplus energy in the form of fat and contribute to thermal insulation of the body

connective tissue proper

largest category of CT, primary cell type is fibroblasts

what three fibers do fibroblasts secrete?

collagen, elastic, and reticular fibers

collagen fibers

great tensile strength, resist stretching, e.g. ligaments and tendons

elastic fibers

contain elastin to return to original shape after stretch and compression

reticular fibers

create a structure and allow space for an organ, strong enough to make a shape while also still allowing things to move

loose connective tissue

found between many organs where it acts to both absorb shock and bind tissues together; areolar, adipose, and reticular

areolar CT

contains all cell types and fibers distributed randomly, fills space, highly vascular

located in muscle fibers, blood and lymph vessels, underlies most epithelia

adipose CT

highly vascular, functions for insulation, energy, water, hormone storage, and support and protect organs, very little extracellular matrix

located in kidneys, neck, clavicle

reticular CT

located where there is a lot of blood flow and large cells needing to go through

located in the spleen

dense connective tissue

contains more collagen fibers and displays greater resistance to stretching than loose CT; dense regular, dense irregular, and elastic CT

dense regular CT

fibers are parallel to each other, enhancing tensile strength and resistance to stretching in the direction of fiber orientations

dense irregular CT

direction of collagen fibers is random, gives tissue greater strength in all directions rather than one particular direction and withstands tension in multiple directions

elastic CT

contains elastin and collagen fibers, main functions are stretch and recoil

skeletal muscle

large, long, cylindrical

striated

voluntary movement

muscles acting on limbs, trunk, and face

movement or stabilization, heat production, protect internal organs

no mitosis but can regenerate

smooth muscle

small, spindle-shaped with tapered ends

not striated

involuntary movement

walls of many internal organs and passageways

move food, urine, secretions and control diameter of vessels

capable of mitosis and regeneration

cardiac muscle

small, short, branched

striated

involuntary movement

heart wall

circulates blood

connected by intercalated discs with gap junction

not capable of mitosis or regeneration

epimysium

sheath of dense, irregular CT surrounding a muscle

perimysium

sheath of CT surrounding each individual fascicle

endomysium

sheath of CT surrounding each individual muscle fiber

fascicle

bundle of muscle fibers

myofibrils

cylindrical structures that runt he entire length of the muscle fiber

myofilaments

actin and myosin proteins in myofibrils

sarcomere

unique individual groupings of actin and myosin

sharpey's fibers

collagen fibers penetrating deep into cortical bone

neuromuscular junction

site where a motor neuron meets the muscle fiber

motor unit

group of muscle fibers in a muscle innervated by a single motor unit controls only muscle fibers of the same type

all-or-none principle

when a motor neuron is stimulated, all muscle fibers in its motor unit will contract; as more motor units are recruited and contract, the muscle contraction grows stronger

slow oxidative (SO) fibers

fibers contract slowly and are aerobic

less power, greater endurance, need greater blood supply

fast glycolytic (FG) fibers

fibers contract quickly and are anaerobic

more power, rapid instead of endurance, use glycogen stores

hypertrophy

resistance training leads to increased size of myofibrils and muscle cells in muscle fibers

two main classes of cells in nervous system

neurons and neuroglia

neurons

transmit information through the body via electrochemical signals

last a lifetime

don't divide

high metabolic rate

neuroglia

cells that support neurons, six different types - four found in the CNS, two found in the PNS

synapse

gap between two neurons or a neuron and its target across which an impulse is transmitted by neurotransmitters

cell body (soma)

most of the cytoplasm, organelles, and nucleus of a neuron

"thinking" part

dendrite

branches receiving most of the input from other neurons and carry it to cell body

axon

only one per neuron, a fiber that emerges from cell body and proejcts to target cells to propagate nerve impulse

pseudounipolar neurons

axon emerges from cell body and splits so that it can extend a very long distance

one end of the axon has dendrites, other end forms synaptic connections with a target

exclusively sensory neurons

bipolar neurons

two processes extend from each end of the cell body opposite to each other

one is axon and one is dendrite

found in olfactory epithelium and retina

multipolar neurons

most common neurons in the body with one axon and two or more dendrites

convergence

multiple presynaptic neurons converge to send a signal to ONE postsynaptic neuron

this amplifies the signal and causes firing

divergence

one presynaptic neurons sends a signal to MANY postsynaptic neurons

this sends the same information to multiple locations

astrocytes

most abundant glial cells in CNS

regulate the environment around neurons and take up/breakdown neurotransmitters or ions in the fluid surrounding the neurons

contribute to BBB

act as CT of the brain

form scar tissue

regulate inflammatory response

involved in synapse formation and neuronal growth

propagate Ca signals involved with memory

microglia

smallest and least abundant in CNS, considered immune cells of the brain

phagocytize debris from dead/dying cells and invading microorganisms around brain and spinal cord

oligodendrocytes

myelinate axons in the CNS

can myelinate multiple parts of multiple axons

inhibit regeneration of neurons

ependymal cells

filter blood to make CSF

Schwann cells

myelinate axons in PNS

surround unmyelinated axons in PNS

can only myelinate one part of one axon at a time

satellite cells

surround cell bodies of neurons in the PNS, isolating them and protecting them from surrounding tissue

wallerian degeneration

in an injury to an axon, the part of the axon distal to the cell body breaks down in a process called fragmentation

portion between the cell body and injured area can stay alive and remain healthy

macrophages clean up damaged cells

Schwann cells form cord/regeneration tube to guide axon back to its target

if there is too much damage, it may not happen at all

not possible in the CNS

nucleus/center

group of neuronal cell bodies in the CNS

ganglion

group of neuronal cell bodies in the PNS

tract

bundle of axons or fibers in CNS

nerve

bundle of axons or fibers in PNS

general somatic sensory

sense of touch, pressure, pain, temperature, and propioception

general somatic motor

voluntary movement by skeletal muscles

general visceral motor

involuntary movement of our cardiac and smooth muscle and secretion from glands

general visceral sensory

monitoring and sensing unconscious information primarily coming from our organs and glands

nervous vs endocrine system

neurotransmitters in synaptic cleft vs hormones in blood stream

rapid vs slow response

short, localized effects vs long, widespread effects

meninges

three layers of connective tissue in which the brain and spinal cord are wrapped