Cells, Tissues, Organs Flashcards
What are the 5 characteristics of a cell
1) irritability : responds to stimulation
2) growth : goes through a life process of birth, development and death
3) spontaneous movement: movement originating and occurring within the cell
4) metabolism: takes in raw products, breaks them down and turns them into usable energy
5) reproduction: through cell division
cell membrane
selectively permeable double layer of molecules surround the outside of the cell
typically comes into play with inflammation and respiration
mitochondria
powerhouse of the cell, creates ATP to breakdown/give us energy
has own DNA/genome, only comes from mothers
10-20 in cell, not all the same can have different genomes
lysosome
breaks down material
golgi body
stores and delivers proteins
proteins for structural support, catalyze, antibodies, transport
centrioles
assist in cell division and microtubule formation
microtubules
support shape of the cell and movement of the organelles
smooth endoplasmic reticulum
stores and releases enzymes and calcium for muscle contraction
rough endoplasmic reticulum
produce, store and releases proteins
ribosomes
synthesize protein as directed by genetic information
Mitochondrial diseases
due to not defect in mitochondria, not enough energy due to lower levels / defects of ATP
as low as 1 in 4500 births
prevalence of dysarthria and dysphagia
genetic testing is the most reliable way to establish a diagnosis of a mitochondrial disorder
what are the 4 types of cells
epithelial cells: selectively absorb molecules and ions (like in the gut) or cover surfaces and form selective barriers (like in the skin)
connective tissue cells: form and secrete various types of extracellular connecting, anchoring, and supporting structures of the body
muscle cells (aka muscle fibres): produce mechanical forces, which in turn produce movement
nerve cells: initiate and conduct electrochemical information
What is a tissue and what are the 4 types
tissues are groups of cells that are similar in structure that band together with extracellular material and function as a unit
types:
1) epithelial tissue
2) connective tissue
3) muscle tissue
4) nervous tissue
epithelial tissue
tissue that lines the internal and external surfaces of the body and the cavities of the body
very little extracellular material
described by shape, number of cell layers and location
epithelial tissues: shape
shape:
- squamous (flat/plate like)
- cuboidal (cube)
- columnar (column)
epithelial tissues: number of cell layers
- simple (1 layer)
- stratified (multiple layers)
- pseudostratified (looks like more than one layer but cells are just different sizes)
epithelial tissues: location
epithelial tissue proper: forms the skin and internal membranes continuous with the skin
endothelial: lines blood and lymph vessels, made of simple squamous cells
mesothelial: 2 layers, lines internal body cavities, secretes seroud fluid
- pericardial (heart)
- pleural (lungs)
- peritoneal (abdomen)
connective tissue
tissue that combines or holds structures together, supports the body, and aids in maintenance
fewer cells than epithelial tissue but more extracellular substance
classified based on composition of the extracellular matrix (loose, dense, specialized)
connective tissue: loose
fills spaces and hold organs, anatomic structures, and other tissues in place
connective tissue: dense
more tightly packed collagen and elastic fibers (collagen = structure and strength, elastin = stretchiness)
able to tolerate higher degrees of tension
3 types:
1) tendons: join muscle to bone, cartilage, or other muscles
2) ligaments: join bone to bone, bone to cartilage, or cartilage to cartilage
3) fascia: covers and separates muscles into functional groups
connective tissue: specialized
cartilage has 3 types
1) hyaline: most abundant type, foudn in rib cage, larynx and nose
2) elastic: very flexible found in the outer ear (pinna, external auditory meatus), epiglottis, cuneiforms, corniculates
3) fibrous: slightly compressible and can withstand great amounts of pressure, found in regions that support body weight (intervertenral discs) and temporormandibular joint
bone: minerals are mixed with matrix which provide more rigidity and hardness
blood: extracellular material is primarily water
muscle tissue
tissue that enables movement due to its contractility
3 types: cardiac, smooth, skeletal
muscle tissue: cardiac (myocardium)
forms middle layer of the heart
responsible for pumping blood
involuntary control
each cardiomyocyte has one nucleus, looks striated, branches to connect with other cells, and has man mitochondria
muscle tissue: smooth
forms muscular portion of the visceral organs (lower esophagus, stomach, lungs) and found within blood vessels
controls size, shape, and movements
nonstriated
involuntary control
muscle tissue: skeletal (striated)
connects to skeletal framework and results in body movement during contraction
larger muscle diameters = greater strength
striated
voluntary control
predominant muscle tissue involved in speech production
muscle tissue levels overall
1) muscle (organ)
2) fascicle (tissue), bundle of this forms the muscle
3) muscle fiber (cell), bundles of this forms the fascicle
4) myofibril (organelle): muscle contraction, made up of myofilaments
nervous tissue
specialized to transmit information across distances via electrochemical means
found in brain, spinal cord, peripheral nervous system
2 types: nerve cells (neurons), glial cells
- neurons: send and receive infor
-glia: supportive function (maintain extracellular, provide structural support, nutrients to neurons)
what are the structures in a neuron
cell body, dendrite, axon, myelin sheath, node of ranvier, axon terminal, synapse
cell body
aka soma
metabolic centre for the neuron
dendrite
specialized processes where the majority of afferent input is received
axon (and hillock / terminal)
responsible for conducting the electrical impulse
axon hillock: the proximal portion of the axon where the soma and the axon meet
axon terminal: distal end of the axon which releases neurotransmitters
myelin sheath
insulating layer that facilitates conduction of electrical signal to move more quickly along the axon
node of ranvier
unmyelinated portions of the axon from which the action potential is observed to jump via saltatory conduction
synapse
space where the elctrochemical signal passes from one neuron to the next
what are the three main shapes of neurons
multipolar neuron: majority of brain neurons, motor function
bipolar neuron: special senses (ie taste)
unipolar neuron: sensory neurons
cell
smallest living unit of the body
vary in shape, size and specific role
tissue
groups of connected cells that share a similar function
each tissue has a characteristic role in processes related to communication
organ
structure composed of at least two diferent tissue types that work synergistically
