Week 2 Flashcards
Describe columnar epithelial cells:
Taller than wide
What do cilia do?
Move material across the surface
What are stereocilia?
Elongated microvilli use for sensation and absorption
Describe apocrine gland:
Secretion accumulate at secreting margins of the cell and the whole margin pinch off and then breaks down.
What are the two components of the nervous system?
1) Central Nervous System
2) Peripheral Nervous System
What are graded potentials?
Change in membrane potential confined to a small region.
Describe microvilli:
Increase surface for absorption and secretion
Describe afferent neurons:
Convery information from tissues and organs to the central nervous system
What are the function of connective tissue:
1) Binds together, support and strengthen other tissues
2) Protect and insulate internal organs
3) Compartmentalize structures
4) Transport substances
5) Stores energy
6) Main source of immune responses.
How do astrocytes form the brain-blood barrier?
By stimulating the formation of tight junctions between the cells that form the capillaries in the CNS.
What are the similarities between K+ and Na+ ion channels?
1) Both have sequences of charged amino acid that change shape in response to a change in the membrane potential
2) Both stay close at negative membrane potential
What are the three types of tissue repair?
1) Labile
2) Stable
3) Permanent
What is an equilibrium potential?
The electrical potential necessary to balance a given ionic concentration gradient across a membrane so that the net flux is zero.
What are the three different types of epithelium according to the number of layers?
1) Simple
2) Pseudostratified
3) Stratified
How do astrocytes sustain neurons metabolically?
By providing glucose and removing ammonia
Describe merocrine gland:
Released via exocytosis from vesicles.
What is summation?
If additional stimuli occur before the graded potential has died away, this can be added to the first.
What are the two majors layes of the skin:
The epidermis and the dermis
Describe transitional epithelium:
The apical cell layers change shape depending upon distention of the organ
Describe the serous tissue membrane:
Simple squamous epithelium called mesothelium, basement membrane and a thin layer of connective tissue. Line cavities not open to the exterior.
Describe oligodendrocytes:
Forms myelin sheats of the CNS neurons.
Describe cuboidal epithelial cells:
About equal in height and width
Describe the main features of cardiac muscle tissue:
Forms the wall of the heart
Cardiomyocites are striated and branching and connected together by a intercalated disc.
Almost completely under involontary control
What are collaterals?
Branched of the axon
What are the 3 components of the neuron?
1) Cell body (soma)
2) Dendrites
3) Axon
What is a membrane potential?
A separation of electrical charges that exists across plasma membranes
What are the two factors that influence neuronal electrical property?
1) concentration gradient of different ions
2) Permeability of the membrane to those ions
How are exocrine glands classified according to their structure?
Unicellular (goblet cells)
Multicellular
What are the two differences between K+ and Na+ ion chanels?
- Voltage-gate Na+ channel respond faster to change
- Voltage gated Na+ channel has an activation gate.
What are the three different types of muscle tissue?
Skeletal muscle tissue
Cardiac muscle tissue
Smooth muscle tissue
Describe permanent tissue repair:
If killed, replaced by a different type of cell. Limited regenerative activity.
What is an intercalated disc?
A large cluster of gap junctions.
What are the functions of epithelial tissue?
1) Protecting underlying structure
2) Acting as a barrier
3) Permitting the passage of substances
4) Secreting substances
5) Absorbing substance
Describe the axon:
A long process that extends from the cell body and carries outgoing signals to target cell.
Describe the movement of kinesin:
It moves from the cell body to the axon terminal (anterograde)
What are the 5 epithelial layers in the epidermis (from bottom to top)
1) Stratum basale
2) Stratum spinosum
3) Stratum granulosum
4) Stratum lucidum
5) Stratum corneum
Describe interneurons:
Connect neurons within the Central Nervous System
Describe efferent neurons:
Convey information away from the central nervou system to effectors.
Describe endocrine glands:
They are in no open contact with the exterior, they have no duct and produce hormones.
Describe Langerhans cells:
Phagocytic dendritic cells involved in immune response
Describe simple (unilaminar) epithelium:
One layer of cell
What are the 3 functions of basement membranes?
1) Attachment to connective tissue
2) Guides cell migration during tissue repair.
3) Acts as a filter in the nephron of the kidney.
What does the peripheral nervous system made of?
Consists of nerves that connect the brain and the spinal cord to body muscles, glands, sense organs and tissue.
What are the two types of glands formed by epithelium:
1) Endocrine
2) Exocrine
What are the 4 different types of free surfaces of epithelium:
Smooth
Microvilli
Cilia
Folds
Describe the main featurs of smooth muscle tissue:
Located on the walls of hollow internal organs
Constist of nonstriated cells with a central nucleus
Under involuntary control
What does the inactivation gate do?
Limit the flux of Na+ by blockin the channel shortly after depolarization opened it.
Describe the synovial tissue membrane:
Line freely movable joints and secrete a lot of hyaluronic acid.
Describe stratum corneum:
Dead cells have a hard protein envelope. Many sublayers of dead keratinocytes (also called corneocytes)
What are the 4 type of tissue:
1) Epithelial tissue
2) Connective tissue
3) Muscle tissue
4) Nervous tissue
What are the functions of the skin?
1) Regulation of body temperature
2) Blood reservoir
3) Protection
4) Cutaneous sensations
5) Excretion and absorption
6) Synthesis of vitamin D
Describe Nerve tissue:
Major integrating and regulating tissue that detect changes in condition and initiates and trasmit nerve signals.
What are the three different types of multicellular exocrine gland according to their functional classification?
1) Merocrine
2) Apocrine
3) Holocrine
What is the axon hillock?
Region of the axon that arises from the soma where electrical signals are generated.
What is the Node of Ranvier?
The space between adjacent myelin sheats where the axon’s membrane is exposed.
What are the three functional classes of neurons:
1) Afferent neurons
2) Efferent neurons
3) Interneurons
What do glial cells do?
Surround the axon and dendrites of neurons and provide them with physical and metabolic support
Why is the membrane polarized?
Because inside and outside have different charges
Describe dendrites:
A series of highly branched outgrowths of the cell that receive incoming information from other neurons.
Describe keratinocytes:
Produce keratin (a fibrous protein that provides protection)
The extracellular matrix is composed of:
1) a ground substances
2) Fibers: gives support and flexibility to the matrix.
What is a nerve?
A groups of afferent and effernt neuron axons together with myelin, connective tissue and blood vessels.
Describe pseudostratified epithelium:
Tissue appears to be stratified but all cells contain basement membrane so it’s in fact simple
Describe the epidermis:
Outer thinner layer that consists of epithelial tissue.
Describe holocrine glands:
An entire mature cell dies and breaks down with the released cell content being the secretion.
What is the function of the axon terminal:
To release neurotransmitter in the synapse
What is a synapse?
Anatomically specialized junctions between neurons.
What are the 4 different cell types of the epidermis:
1) Keratinocytes
2) Melanocytes
3) Langerhans cells
4) Several types of sensory cells.
Describe the movement of dynein:
It moves from the axon terminal to the cell body (retrograde)
What is tissue repair?
Substitution of dead/damaged cells with viable and functional cells
Describe glandular epithelium:
Epithelium with supporting network of connective tissue
What is excitability?
The ability of the cell to produce electrical signals that can trasmit information between different regions of the membrane.
What is plasticity?
The potential for remodelling in response to stimulation or injury
Describe muscle tissue:
Consists of cells called myofibers specialized to contract and therefore provide motion, maintain posture, generate heat.
What does the growth cone do?
Forms the tip of each extending axon and it’s involved in finding the correct root and final target for the process.
What are basement membranes?
Located extracellulary formed by secretion of both epithelial and connective tissue
Describe stratified (multilaminar) epithelium:
More than one layer
Describe cell body:
contains nucelus and most organelles
Describe the main features of skeletal muscle tissue:
It is attached to bone
Consist of cylindrical striate cells
Multinucleate
Under voluntary control
Describe labile tissue repair:
Capable of mitosi through life
Describe mucous tissue membrane:
Line cavities that opens outside the body and secrete mucus.
What are the 3 types of tissue membrane?
1) Mucous
2) Serous
3) Synovial
Describe the dermis:
Inner, thicker layer that is composed of many tissue type (mostly connective)
What are the two components of the axon of the afferent neurons?
Central process and peripheral process.
Describe melanocytes:
Produce the pigment melanin that protect from UV light.
Describe stable tissue repair:
No mitosis after growth ends but can divide after injury.
What are microglia?
Specialized macrophage like cells that perform immune function in the CNS. They also remodel syanpse and plasticity.
How are multicellular exocrine glands classified according to the type of structure?
They can be either simple (ducts with few branches) or compound (ducts with many branches).
Describe epithelial tissue:
Covers body surfaces and lines most organs and body cavities
What is axonal transport?
The movement of organelles along the axon. Depends on scaffolding of microtubules and motor proteins kinesin and dynein.
Describe exocrine glands:
They are in open contact with the exterior and have ducts.
What is integument?
The organs of integumentary system include the skins and its accessory structures
What are the three different types of epithelial cell?
Squamous
Cuboidal
Columnar
What does the concentraion gradient depend on?
1) The Na/K pump estabilishes the concentration gradient
2) Greater net movement of K than N through leak channels.
3) At a negative resting potential, ion fluxes through channels and pumps balance each other.
What is the skin?
The skin covers the body and it’s the largest organ in the body by surface area and weight
What are ependymal cells?
Line the fluid cavities of the CNS and regulate the prodction and flow of cerebrospinal fluid.
Describe squamous epithelial cells:
Flat, scale like cells
Describe astrocyte:
Regulate the composition of extracellular fluid by removing potassium and neurotransmitters
