Module One Flashcards
Communication within the body is essential for homeostasis and is accomplished chiefly by _____ and ____.
Nervous and Endocrine Systems
Homeostatic Control Mechanisms:
Receptor
Essentially, it is some type of sensor that monitors and responds to changes in the environment. It responds to such changes, called “stimuli” by sending information (input) to the second element, the control center. Information flow from the receptor to the control center along the afferent pathway.
Homeostatic Control Mechanisms:
Control Center
Determines the level (set point) at which a variable is to be maintained, analyses the information it receives and then determines the appropriate response or course of action.
Homeostatic Control Mechanisms:
Effector
Provides the means for the control center’s response (output) to the stimulus. Information flows from the control center to the effector along the efferent pathway. The results of the responses then feed back to influence the stimulus, either depressing it (negative feedback) so the whole control mechanism is shut off or enhancing it (positive feedback) so the reaction continues at an even faster rate.
Examples:
- when a fly lands on them (positive feedback)
- stressing the horse (negative feedback)
Most homeostasis control mechanisms are _____
negative feedback mechanisms.
What happens to us when we age?
Our body organs become less efficient and our internal conditions become less and less stable.
What are the four primarily elements that cells are made of? And what are the smaller amounts of several other elements are made of?
1) Carbon, Oxygen, hydrogen and nitrogen.
2) iron, sodium, and potassium
Why are sodium and potassium ions essential?
Because they are needed for nerve impulses to be transmitted and muscles are to contract.
Types of cells: Prokaryotic
- cells have very little visible internal organization, for instance, the genetic material is stored in the molecule DNA, is free within the cell
- all their intracellular water soluble components (proteins, DNA, and metabolites) are located together in same volume enclosed by cell membrane, rather than in separate cellular compartments.
Types of Cells: Eukaryotic
- larger
- can be large enough to see with the naked eye
- structurally more complex
- contain a variety of specialized structure’s known collectively as orangelles, surrounded by viscous substance called cytosol
- their DNA is held within the largest organelle, the nucleus
- the defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is contained
Structures Within the Cell: Nucleus
- seed inside that contains most of the cell genetic material, organized as multiple long linear DNA molecules on complex with large variety of proteins to form chromosomes.
Structures Within the Cell: Nucleoli
- the nucleus contains one or more small, round bodies
- are sites where ribosomes are assembled
- migrate into the cytoplasm and serve as the actual sites of protein synthesis
Structures Within the Cell: Chromatin (primary functions)
- to package DNA into smaller volume to fit in cell
- strengthen DNA to allow mitosis
- to prevent DNA damage
- to control gene expression and DNA replication
Structures Within the Cell: Chromatin
- when a cells is not dividing, its DNA is combined with protein and forms a loose network of bumpy threads called chromatin that is scattered throughout the nucleus. When a cell is dividing to form two daughter cells, the chromatin threads coil and condense to form dense rod-like bodies called chromosomes, much the way a stretched spring becomes shorter and thicker when allowed to relax
- is the combination or complex of DNA and proteins that make up the contents of the nucleus of a cell.
Structures Within the Cell: Plasma Membrane
- is a fragile, transparent barrier that contains the cells contents and separates them from the surrounding environment.
- has a core of two lipid layers
- has proteins in bi-layers
- involved in transport functions
- proteins mounted on the cell exterior are receptors for hormones or other chemical messengers.
What is microvilli?
tiny finger like projections that greatly increase the cell’s surface are for absorption so that the process occurs more quickly
What determines your blood type:
glycoproteins, which act as receptors that certain bacteria viruses or toxins can bind to, and play a role in cell to cell interactions.
What are sugar proteins?
Glycoproteins because of their presence, the cell surface is fuzzy, sticky, sugar rich area.
What are desmosomes?
anchoring junctions that prevent cells subjected to mechanical stress from being pulled apart. (such as skin cells)
In tight membrane junctions what do the adjacent plasma membranes do?
Fuse together tightly like a zipper.
Tight membrane junctions are impermeable junctions that bind cells together into leak proof sheets that prevent substances from passing through the extracellular space between cells. True or False. Give an example
True. Example: in the small intestine these junctions prevent digestive enzymes from seeping into the bloodstream.
How are desmosomes structurally?
These junctions are button-like thickening of adjacent plasma membranes which are connected by fine protein filaments.
Where are gap junctions commonly seen?
They are commonly seen in the heart and between embryonic cells allow communication. Chemical molecules, such as nutrients or ions, can pass directly from one cell to another.
In gas junctions, the neighbouring cells are connected by hollow cylinders (connexions) composed of proteins that span the entire width of the abutting membranes. True or False
True
Structures Within the Cell: Cytoplasm
- the factory area of the cell
- the cellular material outside the nucleus and inside the plasma membrane
What are the three elements of the cytoplasm?
- cytosol: a semitransparent fluid that suspends the other elements
- organelles: the metabolic machinery of the cell (each have a specific function, ex. some synthesize proteins, others package those proteins), “little organs” specialized cellular compartments each performing its own job to maintain the life of the cell
- inclusions: are not functioning units but instead are chemical substances that may or may not be present, depending on the specific cell type. Most inclusions are stored nutrients or cell products.
Structures Within the Cell: Ribosomes
- tiny, round, dark bodies made of proteins and a variety of RNA called ribosomal RNA
- ribosomes are the actual sites of protein synthesis.
When ribosomes are attached to membranes, the whole ribosome membrane combination is called the smooth endoplasmic reticulum (ER). True or False
False. Rough ER
Structures Within the Cell: Endoplasmic Reticulum
- network within the cell
- system of fluid filled cisterns (tubules or canals) that coil and twist through the cytoplasm
- serves as a mini circulatory system for the cell because it provides a network of channels for carrying substances (primarily proteins) from one end to the other
What are the two forms of ER?
Smooth ER and Rough ER
Explain what Rough ER is:
Rough ER is studded with ribosomes. Essentially all of the building materials of cellular membranes are formed either in it or on it, the rough ER can be thought of as the cell’s membrane factory.
In general the amount of rough ER a cell has is a good clue to the amount of protein that cell makes. True or False
True
Explain Smooth ER:
Smooth ER is a continuation of the rough variety, it plays no role in protein synthesis. Instead it functions in cholesterol synthesis and breakdown, fat metabolism and detoxification of drugs.
What ER is found in liver cells mainly?
Smooth ER
What ER is found in pancreas cells mainly?
Rough ER
What is the first structure within the cell to disfunction in an unhealthy cell?
Golgi Apparatus
Structures Within the Cell: Nucleolus
- a structure found in the nucleus of cells, it forms around specific chromosomal regions in the nucleus of Eukaryotic cells made up of mostly proteins and ribonucleic acids
Whats the nucleolus’s function?
- to transcribe ribosomal RNA and combine it with proteins to from incomplete ribosomes
What does RNA stand for?
Ribonucleic Acid
Structures Within the Cell: Golgi Apparatus
- part of the cellular endomembrane system, the Golgi apparatus packages proteins inside the cell before they are sent to their destination. It is particularly important in the processing of proteins for secretion
What does lysosomes mean?
Breakdown bodies
Structures Within the Cell: Lysosomes
- many sizes
- membrane bags containing powerful digestive enzymes
- capable of digesting worn-out or non-useable cell structures and most foreign substances that enter the cell.
- lysosomes are especially abundant in white blood cells that engulf bacteria and other potentially harmful substances because they digest and rid the body of such foreigners.
The enzymes that lysosomes contain are formed by ribosomes and packaged by the golgi appartus. True or False
True
What are peroxisomes?
Membranous sacs containing powerful oxidase enzymes that use molecular oxygen to detoxify a number of harmful or poisonous substances including alcohol and formaldehyde.
What are peroxisomes convert free radicals into?
Hydrogen peroxide
What are free radicals and what disarms them?
Free radicals are highly reactive chemicals with unpaired electrons that can scramble the structure of proteins and nucleic acids. Also Peroxisomes disarm them.
What happens after the peroxisomes convert the free radicals into hydrogen peroxide?
The enzyme catalase then converts excess hydrogen peroxide to water.
Peroxisomes are especially numerous in the small and large intestine cells, which are very active in detoxification. True or False.
False: liver and kidney cells
How do peroxisomes replicate?
They simply pinch in half.
Mitochondria are not found in red blood cells. True or False
True
What happens when enzymes dissolve in the mitochondria?
When they dissolve in the fluid within the mitochondria, as well as enzymes that form part of the cristae membranes, carry out the reaction in which oxygen is used to break down foods. As the foods are broken down, energy is released. Much of the energy escapes as heat, but some is captured and used to form ATP molecules.
What does ATP stand for?
adenosine triphosphate
What does ATP do?
Provides the energy for all cellular work and every living cell requires a constant supply of ATP for its many activities.
What cells have huge amounts of ATP and have hundreds of mitochondria?
Liver and muscle cells, because they are metabolically busy.
What are some of the other tasks does the mitochondria do other than supply cellular energy?
- signalling
- cellular differentiation
- cell death
- the control of the cell cycle and cell growth
What is the cytoskeleton?
- elaborate network of protein structures extends throughout the cytoplasm
- acts as the cells bones and muscles by furnishing and internal framework that determines cells shape
- supports other organelles
Cytoskeleton is made up of mircotubles there are three different types:
- intermediate filaments: help form desmosomes and provide internal guy-wires to resist pulling forces on the cell
- microfilaments (such as actin and myosin): are most involved in cell motility and in producing changes in cell shape
- microtubules determine the overall shape of the cell and the distribution of organelles
Mircotubules are very important during _____.
Cell division
Draw and label a Cell.
look at picture on phone
What are centrioles?
They are rod-shaped bodies, that lay close to the nucleus and lie at right angles to each other. Made up of microtubules.
What is the purpose of cilia?
the ciliated cells of the respiratory system lining move mucus up and away from the lungs to take away bad bateria
What is a solution?
A homogenous mixture of two or more components.
What is a solvent?
The substance largest present in the solution is the solvent. Water is the body’s chief solvent.
What is a solute?
Components or substances present in the smaller amounts are solutes.
What is intracellular fluid?
A solution containing small amounts of gases, nutrients and salts, dissolved in water.
What is interstitial fluid?
Also dissolved in water. The fluid that continuously bathes the exterior of our cells.
The plasma membrane is a ______ ________ barrier which means that a barrier allows some substances to pass through it while excluding others.
Selectively Permeable
When a cell dies, the plasma membrane can no longer be selective and becomes permeable to nearly everything. True or False.
True
Movement of substances through the plasma membrane happen in two ways. Which two ways and explain.
Passive: transported across membrane without any energy input from the cell.
Active Transport: the cell provides the metabolic energy ATP
Molecules will move passively through the plasma membrane by diffusion if one of two things happens. What is this called and what are the ways?
Simple Diffusion: The unassisted diffusion of solutes through the plasma membrane.
1) they are small enough to pass through its pores.
2) they can dissolve in the fatty portion of the membrane.
What is osmosis?
Diffusion of water through a selectively permeable membrane such as the plasma membrane.
Osmosis into and out of cells is occurring all the time as water moves down its concentration gradient. True or False.
True.
Is a protein carrier needed as a transport vehicle in facilitated diffusion?
Yes
What does facilitated diffusion provide?
It provides a means for certain substances, notably glucose, that are both lipid-insoluble and too large to pass through the membrane pores, to enter the cell.
What is filtration?
Filtration is the process by which water and solutes are forced through a membrane (or capillary wall) by fluid, or hydrostatic pressure in the body.
Filtration is necessary for the liver to do its job properly. True or False
False the kidneys.
What are the two most important examples of active transport mechanisms?
Solute Pumping and Bulk Transport
Solute Pumping is similar to facilitated diffusion in that both __________________.
Require protein carries that combine reversibly with substances to be transported across the membrane.
What are some examples that are transported by solute pumps?
Amino acids, some sugars and most ions.
The _____-______ ____ that simultaneously carries ____ ions out and ________ ions into the cell is absolutely necessary for normal transmission of impulses by nerve cells.
Sodium-potassium pump, sodium, potassium
What does bulk transport do?
Some substances that cannot get through the plasma membrane in any other way are transported with the help of ATP into or out of the cell by bulk transport.
What does exocytosis do?
Moves substances out of the cell. It is the means by which cells actively secrete hormones, mucus and other cell products or eject certain cellular wastes. The product to be release is first packaged, typically by the efforts of the golgi apparatus.
What does endocytosis do?
Moves substances in the cell by including those ATP requiring processes that take up, or engulf, extracellular substances by enclosing them in a small membranous vesicle.
What does phagocytosis mean?
Cell Eating
What does pinocytosis mean?
Cell Drinking
Where are pinocytosis most likely to be found?
Cells forming the lining of the small intestine and kidney tubule cells because it is especially important in cells that function in absorption.
Once the vesicle or sac is formed it detaches from the plasma membrane and moves into the cytoplasm, where it fuses with _____ and its contents are ______ by ________ enzymes.
Lysosome, digested by lysosomal.
Bulk Transport:
Exocytosis and endocytosis.
1) during _____, vesicles fuse with the plasma membrane and dump their contents to the outside of the cell.
2) during ______, extracellular substances are incorporated into the cell in vesicles formed by an inward folding of the plasma membrane.
1) exocytosis
2) endocytosis
The cell cycle has two major periods, what are they and what happens?
Interphase, in which the cell grows and carries on its usual metabolic activities and Cell Division, during which it reproduces itself.
The function of cell division is to produce more cells for _____ and ______ ________.
Growth and repair processes.
When is the DNA duplicated?
This occurs toward the end of the cell’s interphase period.
What is DNA composed of?
Composed of building blocks called nucleotides each consisting of deoxyribose sugar, a phosphate group and a nitrogen-containing base.
In DNA replication what are the three steps?
1) enzymes split apart base paris and unwind the DNA double helix.
2) free nucleotides in the cell find their complementary bases along the new strands.
3) The sugar-phosphate backbone is assembled to complete the DNA strand.
Which nucleotides join which nucleotides?
Adenine always bonds with thymine.
Guanine always bonds with cytosine.
Cell Division consists of two events.
Mitosis (division of the nucleus, which occurs first) then division of the cytoplasm, cytokinesis which begins when mitosis is nearly completed.
Explain prophase.
In prophase, the chromatin condenses into discrete chromosomes. The nuclear envelope breaks down and spindles form at opposite “poles” of the cell.
Explain Metaphase.
In metaphase, the spindle fully develops and the chromosomes align at the metaphase plate (a plane that is equally distant from the two spindle poles).
Explain Anaphase.
In anaphase, the paired chromosomes ( sister chromatids ) separate and begin moving to opposite ends (poles) of the cell. Spindle fibers not connected to chromatids lengthen and elongate the cell. At the end of anaphase, each pole contains a complete compilation of chromosomes.
Explain Telophase.
In telophase, the chromosomes are cordoned off into distinct new nuclei in the emerging daughter cells. The chromosomes uncoil to become thread like chromatin again.
The division of the cytoplasm usually begins ____ ______ and completes during ______.
Late anaphase, telophase.
What does it mean when mitosis has gone wild?
The basis for tumors and cancers.
In addition to replicating itself for cell division, DNA serves as the master blueprint for protein syntheses. True or False.
True
What is a gene?
A gene is a DNA segment that carries the information for building one protein or polypeptide chain.
Every chemical reaction that goes on in the body requires a(n) _____.
Enzyme.
Why is there RNA?
DNA never leaves the nucleus. Thus DNA requires not only a decoder but also a messenger to achieve its task of specifying the structure of proteins to be built at the ribosomes (the manufacturing sites for proteins). These messenger and decoder functions are carried out by the second type of nucleic acid called RNA.
How does RNA differ from DNA?
RNA differs from DNA in being single-stranded and in having ribose sugar instead of deoxyribose and a uracil (U) base instead of thymine (T).
What is Transfer RNA (tRNA)?
Molecules which are small cloverleaf-shaped ribosomes, where proteins are built.
What is Messenger RNA (mRNA)?
Molecules which are long, single molecule that carry the message-containing-gene in the nucleus to the ribosomes in the cytoplasm.
Essentially protein synthesis involves two major phases which are?
Transcription: when complementary mRNA is made at the DNA gene
Translation: is decoded and used to assemble proteins.
What are the key elements of an amino acids?
Carbon, hydrogen, oxygen and nitrogen.
How many amino acids are known?
About 500
Amino acids are biologically important organic compounds composed of:
amine (-NH2) and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid.
They can be classified according to the core structural functional groups’ location as:
Alpha, Beta, Gamma, Delta
What is the second largest component of human muscles, cells and other tissues?
Amino acids in the form of proteins.
Outside proteins, amino acids perform critical roles in the processes such as ______ ____ and _____.
Neurotransmitter Transport and biosynthesis.
Groups of cells that are similar in structure and function are called ____.
Tissues.
The four primary tissue types are:
1) epithelium - covering
2) connective - support
3) nervous - control
4) muscle - movement
What are the functions of epithelium tissue?
- protection
- absorption
- filtration
- secretion
The membranes of epithelium tissue always have one free surface or edge, so this is called _____ surface.
Apical
The Apical Surface is exposed to the body’s exterior or to the cavity of an internal organ. What are some of the characteristics of the exposed surfaces and internal surfaces?
Exposed surfaces of some epithelia are slick and smooth but others exhibit cell surfaces modifications such as microvilli or cilia.
Epithelial tissues have blood supply of their own. True or False.
False, these tissues have no blood supply of their own (avascular) and depend on diffusion from the capillaries in the underlying connective tissue for food and oxygen.
What is stratified epithelium?
- forms two or more layers
- more durable than the simple epithelia
- primarily to protect
- squamous or flat
Example of simple sqaumous:
lungs
Example of simple cuboidal:
salivary glands
Example of simple columnar:
digestive tract
Example of stratified sqaumous:
mouth, outer portion of the skin, esophagus
Example of stratified cuboidal:
thymus, glands
Example of stratified columnar:
ducts of large glands
Example of pseudostratified columnar:
urinary system
Most connective tissues are well vascularised but there are exceptions what are they?
Tendons and ligaments have a poor blood supply and cartilages are avascular.
What is the extracellular matrix?
Varying amounts of nonliving substance found outside the cells.
How is the matrix produced?
The matrix is produced by the CT cells and then secreted to their exterior.
Depending on the CT type, the matrix can be:
liquid, semisolid or gel-like or very hard.
The extracellular matrix helps the CT to be able to:
Bear weight, to withstand stretching and other abuses such as abrasion that no other tissue could endure.
CT perform many functions but they primarily involved in:
Protecting, supporting and binding together other body tissues.
Various types and amounts of fibres are deposited and form a part of the matrix material, they include _______, ________, and _______ fibres like the rest of the matrix. The fibres are made by CT cells then secreted.
Collagen (white), Elastic (yellow, and reticular (fine collagen)
All CT consists of living cells surrounded by a matrix. True or False.
True
What are the CT tissues major difference between them?
Their major differences reflect fibre type and the number of fibres in the matrix.
What is bone sometimes called?
Osseous Tissue
Bone is composed of bone cells sitting in cavities called?
Lacunae
What is bone surrounded by and what does it contain?
Surrounded by layers of a very hard matrix that contains calcium salts in addition to larger numbers of collagen fibres.
What is cartilage more of and less than bone?
More flexible and less hard
Where is elastic cartilage found?
Found where a structure with elasticity is desired. For example it supports the external ear.
Tell me about fibrocartilage.
Highly compressible. Forms the cushion-like disks between the vertebrae of the spinal column.
What is the main cartilage found in the body?
Hyaline Cartilage.
What is hyaline cartilage?
It has an abundant collagen fibres hidden by a rubbery matrix with a glossy blue-white appearance.
What does hyaline cartilage main purposes?
It forms the supporting structures of the larynx (voice box), attaches the ribs to the breastbone and covers the ends of the bones.
When babies are in the utero bones are made up mostly of ________ _________, but by the time the baby is born most of it has been replaced by bone.
Hyaline cartilage
What is dense CT also called and what is it made of?
Dense fibrous tissue and has collagen fibres as its main matrix element.
Crowded between the collagen fibres in the dense CT are rows of _______ that _________ the ______.
fibroblasts, manufacture, fibres
What do dense CT form?
Since it is a strong, rope like structure it forms tendons and ligaments. Also makes up the lower layers of the skin (dermis) where it is arranged in sheets
Ligament fibres contain more elastic fibres than tendons. True or False
True
Tell me about loose CT
The loose CT are softer and have more cells and fewer fibres than any other CT type except blood.
The most widely distributed CT variety in the body is:
Areolar Tissue
What are characteristics of areolar tissue?
It is a soft, pliable tissue that cushions and protests the body organs it wraps.
What are the functions of areolar tissue?
It functions as universal packing tissue and CT “glue” because it helps to hold the internal organs together into the proper positions.
A soft layer of areolar CT called Lamia propria does what?
Underlines all mucous membranes.
Because of its loose and fluid nature, loose CT provides a reservoir of water and salts for the surrounding tissues and essentially all body cells obtain their nutrients from and release their wastes into this “tissue fluid”. True or False
False Areolar CT
When a body region is inflamed what does the areolar tissue do?
The areola tissue in the area soaks up the excess fluid like a sponge and the area swells and becomes puffy, a condition called oedema.
What wanders through the areolar tissue?
Many types of phagocytes wander through this tissue, scavenging for bacteria, dead cells and other debris which they then destroy.
Fat cells can store toxins. True or False
True
CT does not have blood supply so it doesn’t heal it just scars. True or False.
True
What is commonly called fat?
Adipose Tissue
Areolar tissue is where _____ cells predominate.
Fat
Where does adipose tissue form?
Adipose tissue forms the subcutaneous tissue between the skin where it insulates the body and protects it from extremes of both heat and cold.
Give an example where adipose tissue protects an organ individually?
Kidneys.
Where are fat deposits in the body so it is available for fuel if needed?
Hips and breasts
What cushions the eye balls in their socket?
Adipose tissue.
What do reticular cells resemble?
Fibroblasts
What does reticular CT consist of?
It consists of a delicate network of interwoven reticular fibres associated with reticular cells.
Reticular tissue is not limited to certain sites. True or False
False. it is limited
What is reticular tissue most important function?
It forms the stroma (bed) or internal supporting framework which can support many free blood cells (largely lymphocytes) in lymphoid organs such as lymph nodes, the spleen and bone marrow.
Why is blood considered a CT?
Because it consists of blood cells surrounded by a nonliving fluid matrix called blood plasma.
Blood is the ______ ______ for the __________ ______, carrying nutrients, ______, respiratory gases and many other substances throughout the body.
Transport Vehicle, Cardiovascular System, wastes
What makes up CT?
Amino Acids
What is the most common cell in CT in animals?
Fibroblasts
What plays a critical role in wound healing?
Fibroblasts
What is elastin?
A protein in CT, which allows many tissues in the body to resume shape after stretching or contracting.
Shapes of Skeletal Muscles: Parallel or Fusiform
These muscles contract over a great distance and usually have good endurance but are not very strong. Ex. rectus abdominus, saratus.
Shapes of Skeletal Muscles: Covergent
The muscle fibres coverage on the insertion to maximize the force of muscle contraction.
Shapes of Skeletal Muscles: Pennate
Many fibres per unit area, these types of muscles are strong but they tie up quickly.
- unipennate
- bipennate
- multipennte
Shapes of Skeletal Muscles: Circular
Muscle fibres surround opening to act as a sphincter (anus)
Shapes of Skeletal Muscles: Fusiform
Classified as parallel muscles that are slightly wider in their middle as fusiform
What is a muscle cell called?
Myofiber or myocite
What is sarcolemma?
plasma membrane of the muscle cell.
What is sarcoplasma?
the cytoplasm of the muscle
What is sarcoplasmic reticulum?
the endoplasmic reticulum of a muscle cell
What is sarcosome?
The mitochondria of the muscle cell
What is sarcomere?
the contractile functional unit of the muscle
Types of Muscles: Smooth
hollow organs, stomach, bladder, uterus, and blood vessels
Types of Muscles: Skeletal
striated
Types of Muscles: cardiac
heart
What are muscles made up of?
Smaller bundles known as fascicles
What are fascicles?
bundles of individual muscle cells
What is the muscle surrounded by?
Surrounded by a CT sheath called perimysium.
Why is each sheath important in the physiology of the muscle contraction?
Because of its electrically insulates, the individual muscle cells are protected from each other
What is the CT tissue sheath known as?
Endomysium
At the ends of the muscle all of the CT sheaths (which are?), converge to form ____ to connect to the _____ attachment site.
epimysium, periysium, endomysium, tendon, bone
What is peristalsis?
A wave like motion that keeps food moving through the small intestine, is typical of its activity.
What is Cytosol?
cytoplasm in the cell.
What does mitochondria do?
ATP synthesis in muscle cell as in all other cells.
What are myofibrils?
Is a cylindrical bundle of contractile protein found within the muscle cell.
What are thin myofilaments?
composed of protein and actin
What are thick myofilaments?
composed of myosin and actin
What are t-tubules?
They are the major sites for coupling of excitation and contraction, which is the process where by the spreading depolarized is converted into force production by muscle fibres.
What are three examples of how the body defends itself at the local tissue level?
- skin and mucous membranes
- cilia
- the strong acid produce by stomach glands
When a tissue is injured what occurs?
It stimulates the body’s inflammatory and immune responses and the healing process begins almost immediately. The immune response is extremely specific and mounts a vigorous attack against recognized invades. (bacteria, toxins, viruses)
Tissue repair or wound healing occurs in two major ways:
1) Regeneration: is the replacement of destroyed tissue by the same kind of cells
2) Fibrosis: involves repair by dense fibrous connective tissue by the formation of scar tissue.
With regeneration and fibrosis happing depends on:
a) the type of tissue damage
b) the severity of the injury
What is granulation tissue?
It is a delicate pink tissue composed largely of capillaries that grow into the damaged area from undamaged blood vessels nearby.
What does granulation tissue contain?
It also contains phagocytes that eventually dispose of the blood clot and connective tissue cells (fibroblasts) that synthesize collagen fibres (scar tissue) to permanently bridge the gap.
Explain the ability of the different tissue keeps how they regenerate.
Epithelial tissues such as the skin epidermis and mucous membranes regenerate beautifully. Skeletal muscle regenerates poorly, it at all. Cardiac muscle and nervous tissue within the brain and spinal cord are replaced only by scar tissue.
Scar tissue is strong but lacks the ______ of most normal tissues.
Flexibility.
What is terrible about scar tissue?
The inability to perform the normal functions of the tissue it replaces. Thus, if scar tissue forms in the wall of the bladder, heart, or another muscular organ, it may severely hamper the functioning of that organ.
When we think of nervous tissue, we think of cells called:
neurons.
What do all neurons do?
All neurons receive and conduct electrochemical impulses from one part of the body to another, thus irritability and conductivity are their two major functional characterisitics.
The structure of the neuron is unique. Draw it.
Draw it.
Neurons, along with a special group of supporting cells, insulate the structures of the nervous system:
the brain, spinal cord and nerves.
What does acupressure mean?
It is based on the concept of life energy which flows through meridians in the body.
How do you help these meridians?
Physical pressure is applied to acupuncture points with the aim of clearing blockages in these meridians.
What is yang?
The element of light, originates in the pores. The active, positive force.
What is yin?
The element of darkness, moves within the five viscera. Is the passive, negative force.
What does qi mean?
Energy.
Homeostatic
Descries the body’s ability to maintain relatively stable internal conditions even though the outside world is continuously changing.
