Final Exam
2 types of excitable cells
neurons and muscle cells
negative feedback
reverses a change in a controlled condition
depolarizing graded potential
makes the membrane less polarized
What is phagocytosis?
"Cell eating", form of endocytosis, cell engulfs waste
structure of plasma membrane
"Fluid mosaic" lipid bilayer, made of phospholipids, cholesterol and glycolipids. -hydrophilic heads(towards water), -hydrophobic tails(away from water)
Three ways muscle cells acquire ATP
1. From creation phosphate 2. Anaerobic glycolysis 3. Aerobic respiration
What is the role of ATP during the contraction cycle?
ATP is hydrolyzed into ADP, energy is stored in myosin head.
Elasticity
Ability to return to original shape after stretching
What is excitation-contraction coupling?
As a muscle action potential propagates along sarcolemma, it releases Ca+ which triggers muscle contraction
What would happen to a red blood cell if placed in a hypertonic solution
Cell shrivels
What would happen to a red blood cell if placed in a hypotonic solution?
Cell swells
function of somatic nervous system
Conveys output from CNS to skeletal muscles only
function of autonomic nervous system
Conveys output from the CNS to smooth muscle, cardiac muscle, and glands
What glands are involved with thermoregulation?
Eccrine sweat glands
endochondral vs intramembranous ossification
Endochondral: replacement of cartilage with bone. Intramembranous: bone forms directly within mesenchyme
Difference between secretions of exocrine and endocrine glands?
Exocrine glands release into ducts (sweat, oil and earwax) Endocrine gland secretions even tear interstitial fluid and diffuse in the bloodstream.
What is the body's preferred source of energy?
Glucose
What are tight junctions?
Inhibit the passage of substances between cellls
Properties of water
Inorganic compound, excellent solvent, polar, cohesion, resist temp change
What is the epiphyseal plate?
Layer of hyaline cartilage in metaphysis
function of ependymal cells
Line ventricles of brain and central canal, produce CSF.
What channels are stimulated during a graded potential?
Mechanically and ligand-gated channels
What is the "powerhouse" of the cell?
Mitochondria
Which is faster: unmyelinated or myelinated axon?
Myelinated
2 systems that maintain homeostasis (back to balance)
Nervous and endocrine
What can pass through the cell membrane?
Non-polar molecules, steroids, small molecules
Where is a cell's DNA is housed?
Nucleus
Types of bone cells and their lineage
Osteoprogenitor cells (RBC lineage), osteoblasts (RBC lineage), osteocytes (RBC lineage), osteoclasts (WBC lineage)
Energy sources for primary active transport vs second active transport
Primary: Hydrolysis of ATP Secondary: Energy stoked in ionic concentration gradient.
What factors contribute to resting membrane potential?
Small build up of negative ions in cytosol, build up of positive ions in ECF.
How does a graded potential spread?
Spreads to adjacent regions along membrane
Sympathic nervous system vs parasympathetic
Sympathetic: supports emergency actions "fight or flight" Parasympathic: slows things down
positive feedback
Tends to strengthen or reinforce a change in controlled condition
What filaments move during the power stroke?
Think filament slides past thick filament towards the center
what channels are in the membrane of the synaptic end bulbs at the neuromuscular junction?
Voltage gated Ca+ channels
The channels that open in the membrane in axon to initiate an action potential
Voltage gates Na+ (rushes in) Voltage gates K+ (flows out)
When does a graded potential occur?
When a stimulus causes mechanically-gated or ligand-gated channels to open or close in an excitable cell's plasma membrane
Extensibility
ability to be stretched
What type of tissue is the epidermis?
epithelial tissue (stratified squamous)
Homeostasis
maintenance of relatively stable conditions in the body's internal environmen
hyperpolarizing graded potential
when the response makes the membrane more polarized (inside more negative)