tissue textbook part 2 Flashcards
(27 cards)
What are the two main characteristics of muscle cells?
Excitable and contractile
Excitable means they respond to stimuli, and contractile means they can shorten and generate pulling force.
What type of muscle is responsible for voluntary movement?
Skeletal muscle
Skeletal muscle is attached to bones and allows for locomotion and facial expressions.
What is the primary function of cardiac muscle?
Contracts to pump blood
Cardiac muscle is found only in the heart.
Where is smooth muscle found?
Walls of major organs and passageways
It controls involuntary movements in systems like digestive and respiratory.
What percentage of body mass is made up of skeletal muscle?
40%
This highlights the significance of skeletal muscle in overall body composition.
What is shivering?
Involuntary contraction of skeletal muscles in response to cold
It helps generate heat to maintain body temperature.
What are myocytes derived from?
Myoblasts derived from the mesoderm
Myocyte numbers remain relatively constant throughout life.
What causes striation in muscle cells?
Regular alternation of contractile proteins actin and myosin
Striations are visible in skeletal and cardiac muscle.
What is a characteristic feature of cardiomyocytes?
Contract on their own intrinsic rhythms
They do not require external stimulation for contraction.
What are intercalated discs?
Specialized cell junctions in cardiac muscle
They connect cardiomyocytes and allow synchronization of contractions.
What does smooth muscle tissue regulate?
Involuntary movements, food movement, respiration, and blood flow
It is essential for the function of several organ systems.
What are the two main classes of cells in nervous tissue?
Neurons and neuroglia
Neurons propagate information, while neuroglia support neurons.
What is the function of the dendrites in a neuron?
Transfer the nerve impulse to the soma
Dendrites receive signals from other neurons.
What part of the neuron carries action potentials away?
Axon
The axon can be wrapped in myelin for insulation.
What is the synapse?
Gap between nerve cells
It is where communication between neurons occurs.
What are astrocyte cells responsible for?
Regulation of ion concentration, neurotransmitter uptake, and blood-brain barrier formation
They have many critical functions in the central nervous system.
What do oligodendrocytes produce?
Myelin in the central nervous system
Schwann cells produce myelin in the peripheral nervous system.
What is inflammation?
Standard initial response of the body to injury
It limits injury extent and initiates tissue repair.
What is necrosis?
Accidental cell death that causes inflammation
It can lead to further tissue damage.
What is apoptosis?
Programmed cell death that does not initiate inflammation
The reasons for this are still unknown.
What are the four cardinal signs of inflammation?
- Redness
- Swelling
- Pain
- Local heat
A fifth sign, loss of function, may also accompany inflammation.
What does histamine do during an inflammatory response?
Causes vasodilation and increases blood flow
It helps recruit white blood cells to the site of injury.
What is edema?
Swelling due to excess liquid in tissue
It occurs when the endothelium becomes ‘leaky’ during inflammation.
What do NSAIDs do?
Reduce pain and inhibit prostaglandin synthesis
High levels also help reduce inflammation.
