Anatomy chpt 3
Terms
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- Parts of the cell
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1.The plasma membrane
2.The cytoplasm
3.The nucleus - PLASMA MEMBRANE
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selective permeable membrane that allows certain substances to get into and out of the cell.
Composed of: Phospholipids,Proteins(Peripheral-transporters, Integral-act as enzymes),Carbohydrates, Cholesterol - Two types of movement that takes place within cells
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PASSIVE MOVEMENT-molecules pass through the plasma membrane from area of higher concentration to lower without use of ATP.
ACTIVE MOVEMENT-when substances move across a selectively permeable membrane from a area of higher to lower concentration with the use of ATP. - Passive Movement includes:
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1.Diffusion-random movement of molecules high to low
2.Facilitated Diffusion-carrier proteins combine temp to molecules allow them to pass through membrane via protein channels
3.Osmosis-when water passes through a selectively permeable from high to low water level.
4.Filtration-process that forces small particles dissolved in a solution to cross semiperm membrane with help of hydorstatic pressure.
5.Dialysis-Exchange of solutions between two solutions seperated by a semiperm membrane. - Active Movement includes:
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1.Active Transport-uses energy from breakdown of ATP to move substances across a semipermeable membrane against a concentration gradient.
2.Exocytosis-fusion of secretory vesicles with the plasma membrane, followed by their expulsion from the cell.
3.Endocytosis-process which particles are engulfed by cytoplasm extensions, forming membrane bound vesicles within the cytoplasm - Three types of Endocytosis
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1.Pinocytosis-"cell drinking", plasma membrane invaginates and encloses small amounts of fluid, releasing them into the cytoplasm.
2.Receptor-mediated endocytosis-when extracellular large molecules bind specific receptors on plasma membrane.
3.Phagocytosis-"cell eating", ability of the plasma membrane to engulf large particles and digest them. - THE CYTOPLASM
- Portion of the cell located between the plasma membrane and the nucleus. Consists of and aqueoud phase and a particular phase.
- Phases in cytoplasm
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Aqueous-"fluid phase", consists of CYTOSOL
Particular-consists of organelles and inclusions. - Organelles
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Endoplasmic Reticulum-network of tubes the channels flow of substances around the cytoplasm.
Smooth/Rough ER-SMOOTH:free of ribosomes,site of steroid synthesis. ER ROUGH-covered in ribosomes, assists in protein synthesis.
Ribosomes-sites of protein synthesis.
Golgi apparatus-flattened sacs that store and package secretory proteins.
Lysosomes-organelles that contain digestive enzymes "suicide bags"
Peroxisomes-involved in formation of hydrogen peroxide.
Mitochondria- have folds called "cristae, are called the "powerhouses" due to ATP production.
ATP-main supplier for most biological activities in the cell.
Cytoskeleton-supportive framwork.
Centrioles-assist in cell division by forming mitotic spindle system.
Cilia-involved in transport of materials along the cell surface.
Flagellum-appendage which protudes from the cell and allow its propulsion.
Secretory Vesicles-contains products of secretion such as protein. - Cytoplasim Inclusions
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1.Lipid droplets-storage for energy
2.Glycogen-principal storage form of carbs
3.Zymogen granules- secretory products rich in inactive enzyme.
4.Melanin pigement- most abundant skin pigment
5.Hemosiderin-yellowish brown pigment from degradation of hemoglobin. - THE NUCLEUS
- Site where gentic material is stored. Consists of three componenets: Nuclear membrane, Chromatin, Nucleolus.
- Nuclear Components
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1.Nuclear Membrane-seperates the nucleus from the cytoplasm
2.Chromatin=fiborous strands containing DNA and proteins.
3.Nucleolus-where RNA is sythesized. - Nuclear Membrane
- Seperates the nucleus from the cytoplasm.
- Chromatin
- Made up of DNA and proteins.
- Nucleolus
- Dense mass where RNA is synthesized
- The Cell Cycle
- Period between beginning of one cell division and the beginning of the the next cell division. Two types of cell division: Somatic and Sex cells.
- Somatic Cell Division
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includes:Interphase, Mitosis, Cytokinesis
Interphase-Active period of cell activity duting which DNA in the nucleus doubles.
Cytokinesis-Division of the cytoplasm into two distinct cells.
Mitosis-Process where two diploid cells result from the division of a parent diploid. Divided into four stages:PROPHASE,ANAPHASE,TELOPHASE,METAPHASE. - Protein Synthesis
- Two major steps:Transcription and Translation
- Transcription
- process where one strand of DNA is used as a template to synthesize a messenger RNA.
- Codon
- A set of three consecutive nucleotides or triplet on mRNA
- Translation
- The formation of a polypeptide under the control of mRNA. Broken down into three stages:Initiation, Elongation,Termination
- Anticodon
- A triplet of nucleotides found on transfer RNA(tRNA). It is complimentary to the codon.
- Initiation
- Always begins with anticodon "UAC", binds to the codon "AUG" of mRNA and begins protein synthesis
- Elongation
- Results from the formation of peptide bonds between different amino acids carried by different tRNA's
- Termination
- Addition of the amino acids to the polypeptide ends when one of the three codons reaches the ribosomes
- Tissues
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A group or cluster of cells with a common function.
Histology-the study of cells - Classification of Tissues
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1.Epithelial Tissue
2.Connective Tissue
3.Muscle Tissue
4.Nervous Tissue - Epithelial Tissue
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Cover the body(epidermis).Composes the secreting parts of endrocine and exocrine glands.
ENDROCINE-secretes hormones into bloodstream,no ducts.
EXOCRINE-secrete into their ducts
Is used in protection,filtration,absorption.Contains a basement membrane used to determine if the epithelium is SIMPLE or STRATIFIED. Comes in four shapes:SQUAMOUS,CUBOIDAL,COLUMNAR,TRANSITIONAL. - Simple and Stratified epithelium tissue
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Simple-one layer of cells attached to basement membrane.
Stratified-more than one layer of cells with the bottom layer attached to the basement membrane. - Epithelial shapes
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Squamous-flat-like
Cuboidal-cube-shaped
Columnar-tall,looklike columns
Transitional-hotair ballons - Connective Tissue
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Found in all parts of the body,connects epithelium tissue to other parts of the body, most abundant tissue in body.
Is used in protection, support.Has two components:Ground substance and Fibers. Types of connective tissue:Embryonic,Areolar,Bone,Blood. - Muscle Tissue
- Highly specialized to contract(shorten) in order to produce movement of some body parts. Has three types of muscles: Skeletal, Cardiac, Smooth
- Types of muscles
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SKELETAL-The "meat" of the body;attached to the skeleton.It is voluntarily controlled.
CARDIAC-Found only in the heart,is uninucleated,is involuntary.
SMOOTH-Smallest muscle cell,also has uninucleated cells,involuntary, found in the walls of hollow organs. - Nervous Tissue
- Composed of two major cell populations: Neuroglia and Neurons.
- Neuroglia
- Special supporting cells that protect,support,and insulate the more delicate nuerons.
- Neurons
- Highly specialized to receive stimuli, and to conduct waves of excitation. They are the cells most associated with nervous system functions.
- Body Membranes
- Fall into two major categories: Epithelial and Synovial
- Epithelial Membranes
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CUTANEOUS-The skin
MUCOUS-Composed of epithelial cells resting on a layer of loose connective tissue called lamina propria.
SEROUS-Composed of a layer of simple squamous epithelium on a scant amount of loose connective tissue. - Synovial Membranes
- Composed of connective tissues, lines the cavaties surrounding the joints.
- Transmembrane Potential
- Outside the cell is slightly positively charged and the inside is slightly negatively charged, phospholipid membrane keep them apart creating a potential difference.
- Resting Potential
- Transmembrane potential of an undisturbed cell.
- Triplets
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Triplets formed on Messenger RNA(mRNA),called a codon.
Triplets formed on Transfer RNA (tRNA), called a anticodon. - Functions of the Integumentary System
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1.Insulates and cushions the underlying tissues.
2.Protects body
3.Acts as excretory system
4.Site for assemblage of vitamin D
5.Large sensory organ - Components of the Cytoskeleton
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1.Microtubules
2.Microfilaments
3.Intermediate Filaments - Appendages of the skin
- Hair,Nails,and cutaneous glands
- Transitional Epithelium
- Lines urinary bladder,only epithelial tissue that can stretch without being damaged.