Exam #4 + Final Exam

What are the general functions of the nervous system?

The nervous system receives sensory information, processes it in the brain, and sends out motor signals to control bodily functions such as movement, breathing, digestion, thinking, feeling, learning, and memory.

What are sensory receptors?

Sensory receptors are specialized cells that detect environmental stimuli and convert them into electrical signals for the CNS.

What is the difference between afferent and efferent neurons?

Afferent neurons carry sensory information to the CNS, while efferent neurons transmit motor commands from the CNS to effectors.

What role does the autonomic nervous system (ANS) play?

The ANS controls involuntary bodily functions and maintains homeostasis by balancing sympathetic and parasympathetic responses.

What is the sympathetic response?

The sympathetic system activates during stress, increasing heart rate, breathing rate, and pupil dilation.

What do neuroglial cells do?

Neuroglial cells provide structural support, maintain ionic balance, insulate axons, and remove debris through phagocytosis.

What are the functions of astrocytes?

Astrocytes maintain the extracellular environment, regulate ion concentrations, and form the blood-brain barrier.

What is the definition of a nerve?

A nerve is a bundle of nerve fibers (axons) that transmits electrical impulses between the brain and the body.

What are mixed nerves?

Mixed nerves contain both afferent (sensory) and efferent (motor) fibers, allowing them to transmit signals in both directions.

What is resting membrane potential (RMP)?

RMP is the electrical potential difference across the neuron's plasma membrane when the neuron is not actively transmitting signals.

What are graded potentials?

Graded potentials are localized changes in membrane potential that vary in size and can summate; they occur in dendrites and cell bodies.

What triggers action potentials?

Action potentials are triggered when the membrane depolarizes to a threshold level, leading to the opening of voltage-gated channels.

What are the two types of ion channels in neurons?

1. Ligand-gated channels that open in response to specific chemical messengers

2. Voltage-gated channels that open in response to changes in membrane potential.

What factors affect conduction velocity of action potentials?

Conduction speed is affected by axon diameter and myelination; larger diameter and myelinated axons conduct impulses faster.

What is the role of the Golgi apparatus in cells?

The Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

What is the function of mitochondria?

Mitochondria generate ATP through cellular respiration, serving as the powerhouse of the cell.

What are the three basic parts of typical cells?

The three basic parts are the cell membrane, cytoplasm, and nucleus.

What determines skin pigmentation?

Skin pigmentation is primarily caused by the presence of melanin, produced by melanocytes in the epidermis.

What are the main types of bone cells?

The main types are osteoblasts (bone formation), osteocytes (maintain bone tissue), and osteoclasts (bone resorption).

What are the main lobes of the brain?

The main lobes are frontal (decision-making, problem-solving), parietal (sensory processing), temporal (auditory processing, memory), and occipital (visual processing).