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eukaryotic cells about 10 μm (100,000 Å)
mitochondria about 1 μm (10,000 Å)
bacteria about 1 μm (10,000 Å)
viruses about 0.1 μm (1,000 Å)
macromolecules about 0.01 μm (100 Å)
molecules about 0.001 μm (10 Å)
hydrogen ion about 0.0001 μm (1 Å)
"The ability to discriminate two points and visualize them as two points, even if extremely close together."
Defined as "half of the wavelength."
Ex: Human eye ~0.1 mm ; Light microscope ~0.2 μm ; Transmission electron microscope ~2-5 Å
Protoplasm is mainly proteins, carbohydrates, fats, salts, and water.
Avg. composition: Oxygen (75+%), Carbon (10+%), Hydrogen (10%), Nitrogen (2+%), Sulfer (about 0.2%), Phosphorus (about 0.3%), Potassium (0.3%), Chlorine (0.1%), <0.1% other.
Every living cell has a plasma membrane ("plasmalemma").
It acts as a permeability barrier between the cell and the environment.
Eukaryotes have diff. membranes that separate compartments in the cell.
All such membranes consist of lipid bilayers.
Lipid bilayers have associated proteins, some associated with the surface of the membrane, whereas other proteins extend across the lipid bilayer.
Membrane surfaces facing away from cytoplasm in eukaryotic cells may have many oligosaccharide groups.
Primary function is to control movement of materials from one compartment to another. This may occur via simple diffusion (which occurs in any liquid) or via carrier-mediated processes (peculiar to biological membranes).
___________ __________ consisting of differences in concentration of a component in a fluid can drive a net movement of that component.
In general simple diffusion will occur from areas of high to low concentration.
1. ______ = > solute cont, < water cont
2. ______ = < solute cont, > water cont
Multicellular animal cells normally operate in 3. ______ body fluids.
In 1. ______ environs animal cells shrink, in 2. _____ environs they swell/burst.
Causes directional conformational changes, & usually ATP is consumed.
Like facilitated diffusion, ________ ________ shows saturation kinetics.
Unlike facilitated diffusion, ________ ________ is sensitive only on one side and saturates at low conct.
1. __________ cells have no nuclear envelope to separate nuclear material from the cytoplasm, are unicellular, and frequently occur in loosely organized colonies.
2. __________ cells contain a nuclear envelope, may be unicellular or multicellular.
Gram-positive bacteria have a cell wall consisting of a thick layer of _______________, which consist of sugars and amino acids. This cell wall supports and protects the individual cell that it surrounds.
_______ are hollow protein tubes that attach bacteria to surfaces and transfer DNA between cells during conjugation (mating).
Histone classes H2A, H2B, H3, and H4 aggregate with DNA to form ___________s. Each ___________ contains two molecules of each histone class comprising a protein core and has two "turns" of DNA (approx. 146 nucleotide pairs) wound around the outside.
_______________ contain actin protein subunits assembled into very thin filaments (5 nm diameter); are usually associated with myosin and other proteins; are bundled into much larger stress fibers in some cells types; capable of contraction.
____A____ ____B___ may include several types of ___B___. Zonula adherens often occur adjacent to conula occludens ___B___. Zonula adherens ___B___ form a mechanical ___A___ between cells, which protects the zonula occludens __B__ in epithelial cells.
Prophase- chromosomes become distinct and nucleolus disappears
Metaphase- chromosomes move to equator and duplicate
Anaphase- two chromatids split apart and start migration
Telophase- chromosomes lengthen, nucleoli reappear
Interphase- cell growth
A. tissue is placed in a fixative solution, which kills and preserves the cells
B. water is removed from the tissues by passing through alcohol solutions
C. placing tissue in a solid medium
D. tissue is cut into sections
E. stained w color dyes
Besides catalyzing assembly of DNA strands, DNA polymerase checks each deoxyribonucleotide after ____________ it and __________ it if base pairing is incorrect.
_______-_______ ___ _________ _________ (ssb protein in E. coli) binds to and protects single-stranded regions of DNA exposed in the lagging strand.
____ ________ synthesizes a short segment of RNA complementary to the template strand of ____. The RNA primer is usually about 10 nucleotides in length, and a new primer is made approximately 200 nucleotides after the last primer segment.
A: the presence (eukaryotic) or absence (prokaryotic) of membrane-bound nuclei in the cell.
B: the number of cells forming the organism.
C: the mechanism for nutrition.
Monera, Protista, Fungi, Plantae, and Animalia.
photosynthetic organisms (plants and algae)
organisms that absorb their nutrients (bacteria and fungi)
and, organisms that engulf or ingest their nutrients (protozoa and animals).
phyla (sing. phylum)
phyla ---> classes ---> families ---> genera ---> species
(with each of these groups capable of being divided into six additional groups)
K: Animalia - consume food via ingestion.
P: Chordata - notochord
S: Vertebrata - segmental vertebral column
C: Mammalia - hair or fur
O: Primates - opposable digits
F: Hominidae - bipedal locomotion
G: Homo - speech
S: Sapiens - large skull
Epithelial tissue (epithelium)
Its characteristics are that it has compactly aggregated cells, limited intercellular spaces and substance, avascular (no blood vessels), basally located basal lamina; polarized cells in sheets; from 3 germ layers.
Simple squamous epithelium.
Located in endothelium of blood lymphatic vessels; Bowman's capsule and thin loop of Henle in kidney; mesothelium lining pericardial, peritoneal & pleural body cavaties; lung aveoli; smallest excretory ducts of glands
microvilli - fingerlike projections from the cell surface
cilia - motile organelles extending in lumen, mainly in respiratory epithelium
flagella - similar to cilia, prime example is spermatozoa
stereocilia - very elongated microvilli
ground substance, cells, and fibers
...and wastes to and from the cells within or adjacent to connective tissue. Is composed of mucopolysaccharides (glyocosaminoglycans), proteins, lipids, water. Primary glycosaminoglycans are chondroitin sulfate and hyaluronic acid.
collagenous, elastic, and reticular
Collagen fibers (white fibers)
Present in structures such as tendons, ligaments, aponeuroses, and fascia, which are subjected to pulling or stretching activities.
are also inelastic, and found in the walls of blood vessels, lymphoid tissues (spleen and lymph nodes), red bone marrow, basal laminae, and glands (liver and kidney).
Adipocytes (fat cells)
Fibrocytes are the main cellular constituents of connective tissue structures such as tendons and ligaments. The terms fibroblast and fibrocyte are often used interchangeably.
Mesenchymal cells ... are primarily found in embryonic and fetal tissues; some are thought to be present in the adult abutting the walls of capillaries. They are smaller than fibroblasts and are stellate in shape. Capable of movement.
Fixed macrophages are very numerous in loose connective tissue. They are polymorphic in shape and contain an oval nucleus; can engulf extracellular material; are difficult to distinguish unless actively phagocytosing...
An adipocyte is a round, large cell with a distinct, dense nucleus usually located at the periphery of the cytoplasm. The cell his a signet ring appearance. Fat cells do not undergo mitosis.
Mast cells; and are soluble in water.
The mast cell granules are composed of histamine and an anticoagulant known as heparin. Mast cells take part in the allergic response of the body, are found in most connective tissue. Et cetera.
The pattern gives a "cartwheel or spoke wheel" appearance. Plasma cells function in protecting the body against bacterial invasion by secreting antibodies [immunoglobulins (IgG)] into the circulating blood.
in certain glands and lymphoid tissues.
various connective tissue cells as well as into smooth muscle cells.
The main leukocytes found in the connective tissue are lymphocytes, monocytes, eosinophils, basophils, and neutrophils. The leukocytes in connective tissue are similar in structure and function to those in the blood.
2. protection of vital organs
3. sites for muscle attachment
4. storage sites of body calcium and phosphates
5. sites for blood cell formation
vertebral canal (which extends from the foramen magnum at the base of the skull through the sacrum)
The vertebral column functions to support the trunk of the body and to protect the spinal cord located in the vertebral canal.
The entire vertebral column is held together by ligaments.
face and cranium
occipital, frontal, ethmoid, sphenoid, vomer, mandible
parietal, temporal, maxillary, palantine, zygomatic, lacrimal, inferior concha, and nasal
The lower jaw or mandible is the only movable part of the skull (head).
middle ear bones (ossicles)
The hyoid bone is suspended in a portion of the neck by muscles and ligaments.
shoulder (pectoral) girdle
skull (22 bones)
ossicles (malleus, incus, and stapes) (6 bones)
vertebral column (26 bones)
ribs (24 bones)
sternum (1 bone)
hyoid (1 bone)
upper extremities (64 bones)
lower extremities (62 bones)
clavicle and scapula
radius (lateral) and ula (medial)
All part of the appendicular skeleton.
wrist (proximal row: scaphoid, lunate, triquetrium, and pisiform) (distal row: trapezium, trapezoid, capitate, and hamate)
The coxal bones attach the lower limbs to the trunk by articulating with the sacrum.
The ____ consists of 5 digits (____) and 5 ___________.
The lower leg contains the ______ and ________.
foot; toes; and metatarsals
From distal to proximal the lower limb consists of foot, ankle, shank, and thigh.
The tibia is larger, located medially, forms the shin, and articulates at the knee joint with the femer (thigh bone).
Bone marrow fills the marrow cavity or smaller marrow spaces depending on the type of bone.
Also, osteons are oriented along the longitudinal axis of the bone.
Blood vessels enter and leave and are distributed throughout bone via the Haversian and Volkmann's canals.
They are remnants of resorbed lamellar systems resulting from the remodeling of the bone.
inner (endosteal) and outer (periosteal) circumferential lamellae, respectively.
The Haversian systems are the major component of compact bone and lie between these two circumferential lamellae.
Both the endosteum and periosteum contain osteogenic cells, which can transform into bone-forming cells, or osteoblasts.
osteocytes, osteoblasts, and osteoclasts
Osteocytes are found singly in lacunae (spaces) within the calcified matrix and communicate with each other via small canals in the bone known as canaliculi, which contain osteocyte cell processes.
They arise from undifferentiated cells, such as mesenchymal cells. They are cuboidal cells which line the trabeculae of immature or developing spongy bone.
They are multinucleated cells lying in cavities, Howship's lacunae, on the surface of the bone tissue being resorbed.
Osteoclasts remove the existing calcified matrix releasing the inorganic or organic components.
Matrix also consists of inorganic material which is about 65% of the dry weight of bone. Approx. 85% of the inorganic component consists of calcium phosphate in a crystalline form (hydroxyapatite crystals).
Some joints are immovable, such as the sutures between the bones of the cranium. Others are slightly movable joints; examples are the intervertebral joints and the pubic symphysis (joint between the two pubic bones of the coxal bones).
...which produces a lubricating fluid - synovial fluid - between the articulating bones.
freely movable joints
The synovial joints can be classified according to the type of motion permitted by the structure of the joint.
They are strong bands that support the joint and may also act to limit the degree of motion occurring at a joint.
A muscle cell also has the ability to propagate an action potential along its cell membrane, as does a nerve cell.
S muscle cells are relatively large in diameter and extremely long, with hundreds of nuclei.
C muscle cells are a syncytium (a large cell-like structure of cytoplasm and many nuclei). The initiation of contraction is intrinsic to cardiac muscle.
It may innervate a few to 2,000 muscle fibers.
Because each motor unit responds as a unit, the number and size of motor units determine many of the characteristics of a muscle.
The gap junction-like components of the intercalated disks allow the ionic charges involved in an action potential to spread from cell to cell in a layer of cardiac muscle. As such, excitation of any point on heart spreads throughout...
B/c the modified cardiac muscle cells at sinoatrial node region of the atria of heart have the most rapid rate of self-depolarization, they serve as the pacemaker region and drive the contraction of rest of heart.
...resulting in the absence of visible cross striations when viewed by light or electron microscopy. Some types of smooth muscle cells appear to be interconnected by modified gap junctions (allow ionic charges --> wave of contraction).
neurosecretory, alters the activity level of the muscle
This is contrasted by synaptic, and alters the activity level of the muscle rather than directly triggers contractions.
and strength play a part. Each muscle consists of many muscle cells or fibers held together and surrounded by connective tissue that gives functional integrity to the system.
endomysium - extracellular matrix and very sparse, loose connective tissue layer enveloping a single fiber.
perimysium - connective tissue layer enveloping a bundle of fibers.
epimysium - connective tissue layer enveloping the entire muscle.
C: insertion - the end attached to a structure that will be moved when the muscle contracts
A pair of muscles usually control the movement of a joint; they are opposing or antagonistic muscles. ex. flexor vs. extensor
Example: The thigh may be rotated medially or internally; it may also be rotated laterally or externally.
In supination the palm of the hand is oriented anteriorly; turning the palm dorsally puts it into pronation. The body on its back is in the supine position.
The body on its belly is in the prone position.
In this movement the thumb pad is brought to a finger pad. A median nerve injury negates this action.
1. Pectoralis major; minor
2. Infra- and supraspinatus
A. Below and above spine of scapula
B. Pectoral region of thorax; major is larger
1 = B
2 = A
1. External and internal intercostals
A. refers to their location in the intercostal spaces
B. Temporal region of head
1 = A
2 = B
1. Pronators; supinators
2. Flexors; extensors
3. Levator scapulae
A. Pronation - down; supination - up
C. elevator of shoulder
1 = A
2 = B
3 = C
1. Biceps brachii
2. Triceps brachii
A. three-headed muscle in posterior brachium (arm)
B. two-headed muscle in anterior brachium (arm)
1 = B
2 = A
1. Flexor pollicis longus and brevis
2. Rhomboid major and minor
A. long and short flexors of thumb
B. major is large; rhomboid shape
1 = A
2 = B
A. extends from sternum to hyoid bone
B. extends from sternum, clavicle (cleido) to mastoid process
1 = B
2 = A
1 = I band bisected by the Z line
2 = A band bisected by the M line
Also, there is a somewhat lighter band within the "A" band called the "H" band. An even lighter area in middle of "H" zone on either side of the "M" line is the "pseudo-H" band.
A ___________, the area between two "Z" bands, is the functional unit of muscle.
sarcomere; it is the region btwn two "Z" lines; consists of an "A" band and half of two abutting "I" bands.
(Striations in muscle fibers are produced by the arrangement within the fibril of myofilaments which comprise the contractile machinery.)
Approx. 54% of all the contractile proteins (by weight) is myosin. The thick filament is composed of many myosin molecules oriented tail-end to tail-end. The head domains are oriented outward.
arranged in a twisted fashion.
This configuration gives the thin myofilament a certain periodicity. Associated w the thin myofilament along its entire length is the globular protein troponin.
Calcium ions released following an action potential in the fiber membrane and T-tubules bind with troponin. Calcium-troponin binding removes the inhibition of actomyosin formation.
sarcotubules (which are continuous with dilated sacs called terminal cisternae)
In skeletal muscle the __________ ___________ lie over the I-A junction of the sacromeres.
The terminal cisternae of cardiac muscle are less well developed and are located adjacent to the Z discs. The terminal cisternae are in associated with invaginations of the sarcolemma T-tubules.
The T-tubules function to bring a wave of depolarization of the sarcolemma into the fiber and thus into an intimate relationship with the terminal cisternae. The sarcoplasmic reticulum concentrates calcium ions (Ca2+) within its lumen...
Each muscle fiber normally has one neuromuscular junction (typically consisting of multiple endings), which is located near the center of the fiber.
It also loses its myelin sheath.
____________ in a skeletal muscle is triggered by the generation of an action potential in the muscle membrane.
It acts at specific sites normally found only on the motor end plate section of the fiber membrane and increases permeability of the motor end plate. Resulting Na+ influx produces a depolarized potential, the end-plate potential.
If muscle length is constant, contraction is an isometric contraction, in which passive tension remains constant with the active tension being added to it to produce the total tension of the muscle.
1) Transport nutrients and oxygen to tissues.
2) Remove waste materials by transporting nitrogenous compounds to the kidneys and carbon dioxide to the lungs
1) transport chemical messengers (hormones) to target organs and modulate and integrate the internal milieu of the body
2) transport agents which serve the body in allergic, immune, and infectious responses
1) initiate clotting and thereby prevent blood loss
2) maintain body temperature
1) produce, carry, and contain blood
2) transfer body reserves, specifically mineral salts, to areas of need