Nervous System and Related Structures

Flashcards for reviewing major concepts of the nervous system, brain structures, sensory receptors, and related anatomical features.

What are the two main divisions of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

What comprises the Central Nervous System (CNS)?

The brain and spinal cord.

What is the primary role of the CNS?

Integration and processing of sensory information.

What does the Peripheral Nervous System (PNS) consist of?

All neural tissue outside the CNS, including cranial and spinal nerves.

What is the function of the sensory (afferent) division of the PNS?

Carries information from receptors to the CNS.

What is the role of the motor (efferent) division of the PNS?

Carries commands from the CNS to effectors (muscles and glands).

What does the somatic nervous system (SNS) control?

Voluntary movement of skeletal muscles.

What functions does the autonomic nervous system (ANS) regulate?

Involuntary functions like heart rate, digestion, and gland secretion.

What are the two subdivisions of the ANS?

Sympathetic and parasympathetic.

What is the function of neuroglial cells?

Support and maintain the environment for neurons.

What are the three main parts of a typical neuron?

Cell body (soma), dendrites, and axon.

What is the role of dendrites in a neuron?

Receive incoming signals from other neurons.

What is the axon responsible for in a neuron?

Carries signals away from the cell body.

What are the three structural classifications of neurons?

Multipolar, bipolar, and unipolar neurons.

What type of neuron is most common and found in the CNS?

Multipolar neurons.

Where are bipolar neurons typically found?

In sensory structures, like the retina.

What is the function of sensory (afferent) neurons?

Carry information to the CNS.

What are gray matter and white matter in the nervous system?

Gray matter contains neuron cell bodies, white matter contains myelinated axons.

What is a synapse?

The junction where a neuron communicates with another cell.

What is the primary function of myelin sheaths?

Insulate axons and increase the speed of impulse conduction.

What is the resting membrane potential (RMP) of a neuron?

About -70 mV.

What is depolarization in terms of action potential?

Na⁺ channels open, allowing Na⁺ to rush into the neuron.

What function does the thalamus serve in the brain?

Acts as the relay station for sensory information.

What are the four major regions of the brain?

Cerebrum, diencephalon, brainstem, cerebellum.

What is the function of the hypothalamus?

Maintains homeostasis and regulates various bodily functions.

What is the role of the cerebellum?

Coordinates voluntary movements, balance, and posture.

What are the three layers of the meninges?

Dura mater, arachnoid mater, and pia mater.

What is cerebrospinal fluid (CSF) responsible for?

Cushions the brain, provides nutrients, and removes waste.

What is dual innervation?

Most organs receive input from both sympathetic and parasympathetic divisions.

What types of sensory receptors are there?

Mechanoreceptors, thermoreceptors, nociceptors, photoreceptors, and chemoreceptors.

What distinguishes general senses from special senses?

General senses are distributed throughout the body, while special senses are located in specialized organs.

What is the primary somatosensory cortex responsible for?

Receiving general sensory information from the body.

What is the main role of the autonomic nervous system (ANS)?

Regulates involuntary control of body functions.

What neurotransmitter is primarily used in the somatic nervous system?

Acetylcholine.

What are the effects of the sympathetic division on the body?

Increases heart rate, dilates airways, decreases digestion.

What are the effects of the parasympathetic division?

Decreases heart rate, stimulates digestion, conserves energy.

What structures make up a spinal nerve?

A combination of sensory and motor fibers.

What is the primary distinction between striated and non-striated muscle tissue?

Striated muscle tissue is voluntary (skeletal), while non-striated is involuntary (smooth).

What is the main function of skeletal muscle?

Movement, posture, joint stabilization, and heat production.

What is the structure of a sarcomere?

The basic unit of muscle contraction.

What do osteoblasts do?

Build bone by secreting the bone matrix.

What is the role of osteoclasts?

Break down bone during resorption.

What is the main component of bone matrix?

Collagen fibers (organic), calcium phosphate (inorganic).