Muscle and Connective Tissue Types Quiz

Types of Connective Tissues

• Dense irregular connective tissue can withstand stress in all directions.
• Reticular connective tissue provides a framework for lymphatic organs.
• Dense elastic connective tissue allows for stretch and recoil.
• Elastic cartilage maintains shape while being flexible.
• Bone contains red marrow.
• Blood transports immune cells and hormones.

Muscle Tissue Characteristics

• Skeletal muscle has more than one nucleus and is under voluntary control.
• Smooth muscle lacks striations and is found in hollow organs (e.g., stomach, intestines, bladder, blood vessels, uterus).
• Cardiac muscle is found in the heart and has intercalated discs, facilitating heart contractions.

Organ Functions and Systems

• Organs function differently due to the specific tissues they contain, specialized for particular functions.
• Integumentary system: skin (protection, temperature regulation).
• Skeletal system: bones (support, protection, movement).
• Muscular system: muscles (movement, thermoregulation).
• Nervous system: brain, spinal cord, nerves (control, communication).
• Endocrine system: glands (hormone production, regulation).
• Cardiovascular system: heart, blood vessels (transport of nutrients, gases).
• Lymphatic system: lymph nodes, vessels (immune response, fluid balance).
• Respiratory system: lungs, trachea (gas exchange).
• The central nervous system consists of the brain and spinal cord.

Peripheral Nervous System

• The peripheral nervous system comprises nerves (bundles of neuronal axons) and ganglia (clusters of neuronal cell bodies).

Sensory and Motor Nervous Systems

• Sensory nervous system gathers sensory information and relays it to the CNS, divided into:
  • Somatic sensory: consciously perceived stimuli (senses).
  • Visceral sensory: non-consciously perceived internal stimuli.
• Motor nervous system transmits motor information from the CNS:
  • Somatic motor: voluntary movements of skeletal muscles.
  • Autonomic motor: involuntary control of cardiac/smooth muscles and glands.

Neuron Structure and Function

• Sensory neurons conduct input toward the CNS; motor neurons carry output away from it.
• Interneurons process information within the CNS, connecting sensory and motor neurons.
• Multipolar neurons: many dendrites, one axon (most motor and interneurons).
• Bipolar neurons: one dendrite, one axon (associated with special senses).
• Unipolar neurons: continuous dendrite and axon with the cell body off to the side (most sensory neurons).

Ion Movement in Neurons

• Pumps move substances against gradients; channels facilitate movement down gradients.
• Types of channels:
  • Leak channels: always open, permit free ion movement.
  • Chemically gated channels: open upon neurotransmitter binding.
  • Voltage-gated channels: open in response to membrane potential changes.

Neuronal Segments and Functions

• Receptive segment: contains chemically gated channels (Na+, K+, Cl-).
• Initial segment: contains voltage-gated channels (Na+, K+).
• Conductive segment: contains voltage-gated channels (Na+, K+).
• Transmissive segment: contains voltage-gated channels and pumps (Ca++).

Membrane Potential Dynamics

• Resting membrane potential is created by Na+ and K+ distribution across the membrane.
• Electrical gradients arise from negatively charged proteins unable to cross the membrane.
• Na+/K+ pump is essential for maintaining resting membrane potential.

Graded Potentials and Action Potentials

• Graded potentials vary in strength; depolarization involves Na+ (cation) entering the cell, increasing positivity.
• Repolarization occurs when K+ (cation) exits the cell, making the inside more negative.
• Refractory periods:
  • Absolute refractory period: Na+ channels inactive; cannot generate another action potential.
  • Relative refractory period: Na+ channels in a resting state; stronger stimulus needed.

Glial Cells and Myelin

• CNS glial cells:
  • Astrocytes: blood-brain barrier, support, fluid regulation.
  • Ependymal cells: line cavities, produce CSF.
  • Microglia: immune defense, remove debris.
  • Oligodendrocytes: myelin sheaths around axons.
• PNS glial cells:
  • Satellite cells: insulate and regulate cell bodies in ganglia.
  • Schwann cells: form myelin sheaths around PNS axons.
• Myelin increases action potential speed and covers axons; neurofibril nodes are gaps between myelin sheaths.

Conduction Methods

• Continuous conduction: occurs in unmyelinated axons, slower due to sequential activation.
• Saltatory conduction: faster, as action potentials jump between myelin sheaths.

Test your knowledge on various types of muscle and connective tissues. This quiz covers definitions, characteristics, and functions of different tissue types, including skeletal, smooth, and cardiac muscle. Dive into the unique qualities of different connective tissues as well.