Anatomy & Physiology (Test 2) Flashcards
Cell Growth
-depends on using genetic information in DNA to make structural & functional proteins (protein synthesis) needed for cell survival
Cell Reproduction
-ensures that genetic information is passed from one generation to the next
DNA (deoxyribonucleic acid)
- contains genetic information that determines expression heritable traits
- structure resembles a long, narrow, spiral staircase, referred to as a ‘double helix’
DNA ‘building blocks’
- sugar (deoxyribose) & phosphate make up the sides
- base pairs (A T) or (C G) make up the ‘steps’
- always paired (A T) & (C G)—complimentary/obligary base pairing
Gene
-a specific segment/sequence of base pairs within a DNA molecule
Genes dictate formation of ______ & other proteins by ______.
- enzymes
- ribosomes
Although the types of base pairs in all chromosomes are the same, the ______ varies.
-sequence
Each gene directs ______ function & protein synthesis.
-RNA
A human gene consists of approximately ______ base pairs (which contain the code for making one RNA molecule, which will be translated to make one ______).
- 1000
- polypeptide
DNA in the nucleus contains the ‘master code’ for protein synthesis, which occurs in the ______.
- cytoplasm
How does the ‘master code’
for protein synthesis get out of the nucleus & into the cytoplasm?
-with the help of various types of RNA, via the processes transcription & translation.
RNA (ribonucleic acid)
- single stranded
- composed of sugar (ribose), phosphate & base pairs (C G & T U)
How does genetic information get from the nucleus to the cytoplasm?
1) transcription-
2) translation- occurs in the cytoplasm & involves mRNA, tRNA and rRNA
3 Types of RNA
- mRNA: messenger RNA (coding RNA)
- tRNA: transfer RNA (non coding RNA)
- rRNA: ribosomal RNA (non coding RNA)
Transcription
-occurs in the nucleus between DNA & mRNA
-double stranded DNA unwinds or unzips
-single stranded mRNA forms along a segment of one strand of the unzipped DNA
mRNA is ‘edited’ & then moves into cytoplasm
Translation
- occurs in the cytoplasm & involves mRNA, tRNA & rRNA
- after leaving the nucleus & being edited, mRNA associated with a ribosome (which contains rRNA) in the cytoplasm
- tRNA molecules then bring specific amino acids to the mRNA at the ribosome; the type of amino acid is determined by 3-base pair sequences called codons on the mRNA & anticodons on the tRNA
- as amino acids are brought into place, peptide bonds join them, resulting in the creation of a polypeptide chain—>protein
Mitosis
- when a cell is actively dividing
- process in cell division that distributes identical chromosomes (DNA molecules) to each new ‘daughter’ cell that is formed when the original cell divides
- enables cells to identically reproduce their own kind
Interphase
-when a cell is not actively dividing
Before a cell can divide (cell reproduction), it has to make a copy of it’s ______, so that it can be equally shared among the ______ ______.
- DNA
- daughter cells
DNA Replication
-a process by which each half of a DNA molecule becomes a whole molecule identical to the original DNA molecule
Newly formed cells produce a variety of molecules & other substances required for growth/maintenance by using the ______ contained in DNA’s ______.
- information
- genes
DNA unwinds, separates at a point between base pairs, and each ‘side’ ______ it’s ______ ______ until each strand is a whole one again (identical to the original). It the proceeds ______.
- attracts
- complementary base
- mitosis
4 Stages of Mitosis
1) prophase
2) metaphase
3) anaphase
4) telophase
Fertilization of an ovum & sperm leads to a diploid cell, called a…
-zygote
How many chromosomes does a zygote get from each parent?
- 23 from each parent
- 64 in total
Body cells (somatic cells/asexual cells) contain ______ chromosomes aka ‘diploid’ number of chromosomes.
46
22 homologous pairs + 2 others, which are the sex chromosome ______ or ______.
XX or XY
______ sex cells also have the diploid number (46) of chromosomes.
Immature
Gametes
-sperm or ovum
______ is the process by which the diploid number of chromosomes in the immature cells is reduced to the ______ number of chromosomes (23) found in mature sex cells which are called ______.
- meiosis
- haploid
- gametes
Zygote
-a fertilized sperm & ovum that is a diploid cell
A zygote will have ______ chromosomes from each parent.
23
Cutaneous
skin
Serous
facing inside body
Mucous
inside body, but connection to the outside (eye, mouth, rectum)
Tissue
-a group of cells, held together by an extracellular matrix, which are similar in structure & perform common or related functions
4 Main Types of Tissues
1) epithelial
2) connective
3) muscle
4) nervous
Within ______ weeks of conception, there is organization of cells into ______ primary germ layers.
- 2
- 3
3 Primary Germ Layers
1) endoderm
2) mesoderm
3) ectoderm
Histogenesis
-the cells of each germ layer differentiate to form specific tissues, eventually giving rise to the various organs & tissues
Extra means…
outside or beyond
Matrix
a surrounding medium or structure
Extracellular Matrix Components
1) collagen
2) elastin
3) glycoproteins & proteoglycans
Collagen
- twisted bundles of fibres
- very strong/can be stretched
- most abundant
- weakens with age
Elastin
-rubbery & stretchy
Glycoproteins & Proteoglycans
-combo of proteins & carbohydrates
What removes damaged tissues?
phagocytosis
Epithelial & connective tissues have the ______ capacity to repair.
-greatest
Muscle & nerve tissues have ______ ______ to repair.
-limited ability
Cartilage is ______ to repair.
-slow
Keloid Scars
-unusually thick scars that develop in lower layers of the skin
Membrane
- thin, sheet like structure
- found throughout the body
- cover & protect internal & external surfaces & organs
- anchors organs & bones
- secrete lubricating fluids to reduce friction
2 Major Types of Membranes
1) Epithelial
2) Connective Tissue
3 Types of Epithelial Membranes
1) cutaneous
2) serous
3) mucous
Epithelial Membranes
-most diverse & widespread tissue in the body
2 Layers of Serous Membrane
- visceral (covers organs)
- parietal (lines cavity wall)
Cutaneous Membrane
- the skin
- primary organ of the integumentary system
- largest organ (16% of body weight)
- made up of: superficial layer of epithelial cells & underlying layer of supportive connective tissue
2 Layers of Serous Membranes
1) epithelial sheet: thin layer of simple squamous epithelium
2) connective tissue layer: thin, supportive basement membrane
Pleura
in lungs
Peritoneum
in abdomen
Pleurisy
-inflammation of the serous membranes that line the chest cavity & cover the lungs (the pleura)
Peritonitis
-inflammation of the serous membranes that line the walls of the abdominal cavity & cover the abdominal organs (the peritoneum)
Mucous Membranes (mucosa)
-lines body surfaces that open directly to the exterior of the body (ex. lining of ducts & passages of respiratory, digestive, urinary & reproductive tracts)
Epithelial cells produce ______ to keep the membranes soft & moist to protect underlying cells.
-mucous
Connective Tissue Membranes
- do not contain epithelial components
- synovial
2 Types of Epithelial Tissue
1) membranous (everywhere else)
2) glandular (glands)
Membranous Epithelium
-covers the body & some of it’s parts; lines the serous cavities, blood & lymphatic vessels, respiratory tract, digestive tract, and genitourinary tract
Glandular Epithelium
-secretes units of endocrine & exocrine glands
Functions of Epithelial Tissue
- protection
- sensory functions: special epithelial structures in the skin, nose, eyes & ears
- secretion: hormones, mucous, digestive juices & sweat
- absorption: gut & respiratory tract
- excretion: kidney tubules
Generalizations of Epithelial Tissues
- limited amounts of matrix material
- tightly packed sheets of cells, with many desmosomes and tight junctions
- membranous type attached to a basement membrane
- avascular
- capable of reproduction
Simple Squamous Epithelium
- single layer of flat & scale shaped cells
- structure perfect for transport/diffusion (ex. absorption of oxygen into blood)
- permeable to many substances
- located in alveoli of lungs, lining of blood & lymphatic vessels
Simple Cuboidal Epithelium
- single layer of cube shaped cells
- often specialized for secretory activity (saliva, digestive juices, sweat, hormones)
- usually grouped into tubules or clusters/glands
Simple Columnar Epithelial
- single layer of tall, narrow, column shaped cells
- composes surface of mucous membranes that line stomach, intestines, part of respiratory system & reproductive system
- contains mucous producing goblet cells
- specialized for absorption (ex. microvilli)
Pseudostratified Columnar Epithelium
- columnar cells of varying heights
- single layer of cells that wedge together to appear as if they are 2 or more layers
- each cell touches basement membrane
- lining of respiratory tract (ex. trachea) & parts of reproductive system (ex. moves egg in fallopian tube)
Glands
-can be endocrine (ductless) or exocrine (duct)
Tubules
-urine producing tubules of kidneys
Stratified Squamous Epithelium
- several layers of closely packed cells
- protection is primary function
- can be keratinized or non keratinized
Stratified Cuboidal Epithelium
- 2 or more rows of cuboidal cells randomly arranged over a basement membrane
- protective function
- located in sweat glands, pharynx, epiglottis
Stratified Columnar Epithelium
- multiple layers of columnar cells
- only most superficial cells are typical in shape
- protective
- rare (ex. located in segments of male urethra & near anus)
Stratified Transitional Epithelium
- up to 10 layers of roughly cuboidal shaped cells that distort to squamous shape when stretched
- protective function
- found in body areas subject to stress & that stretch (ex. urinary bladder)
Glandular Epithelium
- specialized for secretory activity & can function on their own (unicellular glands) or in clusters (multicellular glands)
- exocrine glands: discharge secretion into ducts
- endocrine glands: “ductless” glands; discharge secretions directly into blood or interstitial fluid