TA review questions Flashcards
What cell produces the ground substance of cartilage?
chondroblast
Bone formation begins in? And ends in?
utero ends after puberty
A muscle fiber is larger than a muscle cell. True or false?
False, they’re the same thing (myofiber)
What are lacunae?
Small spaces in which a chondrocyte or osteocyte resides
When does bone remodeling begin and end?
begins in utero and continues throughout the organisms life
Many muscle cells make up the length of the muscle: T or F?
False muscle cells are the same length as the muscles they are apart of
The differences between cartilage types are determined by the molecular composition of the ground substance. T or F?
False fibers determine it
Osteoprogenitor cells differentiate into?
Osteoblasts and they arise from the mesenchyme, found on all surfaces of bones
Explain what syncytium means
single cell with multiple nuclei. Skeletal cells are multinucleated
What is the perichondrium?
layer of dense connective tissue surrounding cartilage, contains fibroblasts; the inner layer can make chondroblasts
Osteoblasts are PAS positive or negative?
Positive because GAGs become part of the matrix
T or F, the muscle has unique organelles that have specific functions and form compared to other cells in the body
True, they have a sarcoplasmic reticulum, sarcolemma and are unique to muscle and have specialized function for muscle tissue
Appositional growth vs interstitial growth
Appositional growth: adding layers to cartilage matrix to the existing outer surface. Interstitial growth: process of new matrix being formed from the core of cartilage by chondroblasts (can apply to bone)
2 types of bone based on embryological origin
intramembranous and endochondral bone
What is the external lamina of skeletal muscle similar to?
the basement membrane have almost the same composition
Where can hyaline cartilage be found?
Nose, trachea, joints of long bones, cartilaginous precursor of long bone in embryonic development (endochondral ossification)
What are intramembranous bones?
form via ossifications of the embryological membrane, flat bones
What is endomysium?
connective tissue that surrounds the skeletal muscle cells make up of collagen type I and III fibers
Composition of hyaline cartilage?
Collagen type II 40%, and 60% GAGs
What are endochondral bones?:
long bones: arise from hyaline cartilaginous precursor
True or false: periosteum forms inside the epiphysis of endochondral bones at 10 weeks post conception?
False forms in the diaphysis at 10 weeks
Is the sarcoplasmic reticulum continuous or fragmented?
Fragmented: sarcoplasmic reticulum units are stacked, hollow membranous organelles
True or false: all cartilage has a perichondrium
False fibrocartilage doesn’t have one no boundary
What are t-tubules?
holes in the cell membrane of muscle cells that form a branching network perpendicular to the cell surface. The distance between one and the next is uniform. small distance followed by large
What is the composition of fibrocartilage?
collagen type I produced by fibroblasts and collagen type II and sulfated GAG’s produced by chondroblasts
What is the bony collar?
layer of bone that forms around the diaphysis of endochondral bones after osteoblasts secrete osteoid on top of the cartilaginous precursor
What is a triad?
terminal cisternae, t-tubule, terminal cisternae
Where can fibrocartilage be found?
Junction of tendon and long bone, vertebral disks between vertebrae
What does the nervous system work in conjunction with? What are these systems called together?
endocrine system ES + NS = communication network
What is the composition of elastic cartilage, and where is it found?
elastic fibers and collagen type II, it is found in the external ear and epiglottis (stretchy and flexible)
What are the location and function of the sympathetic and parasympathetic nervous systems?
sympathetic-mid spinal cord, function: stress parasympathetic: upper and lower spinal cords (brainstem) function: rest and digest (normal body functions)
Inorganic component of bone
hydroxyapatite (calcium and phosphate)
What types of tissue are innervated by the autonomic nervous system?
Smooth muscle, cardiac muscles, and glands (involuntary functions)
Compact vs spongy bone
compact is the outer layer and is dense spongy bone: on the inside, open porous network
Nerve fiber refers to the whole nerve cell. T or F?
False nerve fiber refers to the axon of the nerve cell. The nerve cell is the neuron.
What is the classification of sensory neurons based on the number of cell processes?
Pseudo-unipolar 1 axon with 2 branches and 0 dendrites
What is the blood forming tissue in bone?
Red marrow
What are the 3 classifications of neurons? Which is the most abundant?
motor neurons (receive messages from central nervous system), sensory (receive stimuli and carries them to the CNS), and interneurons (most abundant)
Where are Sharpey’s fibers found?
The periosteum. Strands of collagen type I penetrate into the bone and are continuous with tendon fibers
The autonomic nervous system and somatic nervous system both use acetylcholine and norepinephrine as neurotransmitters. T or F?
False: somatic uses only acetylcholine. autonomic : parasympathetic uses acetylcholine sympathetic uses both acetylcholine and norepinephrine
Which enzyme catalyzes the formation of hydroxyapatite?
alkaline phosphatase secreted by the osteoblast in a membrane bound vesicle
A bipolar neuron is the most abundant neuron type T or F?
False, they are rare. They are found where we have special senses (ears, eyes, nose)
What is an osteocyte?
Mature bone cell that is trapped in a matrix lacuna. Can become active in small bone repairs
Describe a multipolar neuron and where they are found
1 axon and greater than or equal to 2 dendrites and they are found in motor neurons and interneurons
What is an osteoclast?
Macrophagic cells that breakdown bone and are part of the mononuclear phagocytic system
What is the blood brain barrier?
Functional barrier that allows tighter control than that in most tissues over the passage of substances moving from blood into CNS tissue. Tight junctions
Function of choroid plexus?
filters blood to produce cerebrospinal fluid
Where do we see more branching occur, dendrites or axons?
Dendrites have more branching, however we can see terminal arborization in axons. Major axon branches are called collaterals
What is the circulatory system of bone called?
Osteon
