Brain and Spinal Cord

Overview of Central Nervous System Structure and Function

The brain and spinal cord are the primary components of the central nervous system (CNS), responsible for processing and transmitting information throughout the body.

• Dura mater: The tough, outermost membrane covering the brain and spinal cord, providing protection.

• Primary Sensory Cortex location: Located in the parietal lobe; responsible for processing sensory information from the body.

• Ingredients of CSF (Cerebrospinal Fluid): CSF contains water, electrolytes, glucose, and proteins; it cushions the CNS and removes waste.

• Lumbar puncture procedure: A diagnostic procedure to collect CSF from the lumbar region for analysis.

• Function of Cerebrum: Conscious thought process. Memory storage and processing.

• Location of cerebral aqueduct: Connects the third and fourth ventricles.

• Location of Wernicke's Area and names for it: Found in the left temporal lobe; involved in language comprehension. Speech area.

• Structures of Diencephalon: Includes the thalamus, hypothalamus, and epithalamus; involved in sensory relay and homeostasis.

• Function of the Medulla oblongata: Controls autonomic functions such as breathing, heart rate, and blood pressure.

• Functions of cerebellum: Motor coordination, precision, and accurate timing.

• Acetylcholine association: Acetylcholine is a neurotransmitter involved in muscle activation and memory.

• Specialty cortices within the temporal lobe: Auditory cortex.-sound Wernicke's area-language. Olfactory cortex-smell.

• Function of limbic lobe and system: The Limbic lobe regulates emotions. Linking the conscious, intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brainstem. Known as a motivational system.

• When is the parasympathetic system active? During rest and digestion, it conserves energy.

• Functions and locations of ependymal cells: Ependymal cells line the ventricles and produce CSF.

Additional info: The CNS integrates sensory input and coordinates motor output, essential for homeostasis and behavior.

Eye

Structure and Function of the Eye

The eye is a complex organ responsible for vision, converting light into neural signals that are then transmitted to the brain.

• Rods and cones are what type of cells: photoreceptors

• Function of the Lacrimal apparatus: Controls lens shape for focusing.

• Function and dysfunction of aqueous humor: Maintains intraocular pressure and nourishes the lens and cornea; dysfunction can lead to glaucoma.

• Visual purple: Also known as rhodopsin. visual pigment found in rods.

Ear

Anatomy and Physiology of Hearing

The ear detects sound and maintains balance through specialized structures.

• Function of semicircular ducts: Detect rotational movement for balance.

• Bones of the middle ear: Malleus, incus, and stapes transmit sound vibrations.

Nerve Cells

Neuronal Structure and Action Potentials

Nerve cells (neurons) transmit electrical signals throughout the nervous system.

• Threshold stimuli: minimum stimulation needed to trigger a response

• Schwann cells: Surround all axons in the PNS; are responsible for myelination of peripheral axons; participate in the repair process after injury.

• Repolarization phase of an action potential: The repolarization phase restores the resting membrane potential to its original value.

• Astrocytes: Maintain the blood-brain barrier; provide structural support; regulate ion, nutrient, and gas concentrations; absorb and recycle neurotransmitters; form scar tissue.

• All or nothing principle: An action potential either occurs fully or not at all.

• Ependymal cells: Glial cells that produce and circulate CSF. Cerebrospinal fluid.

General Senses

Types and Functions of Sensory Receptors

General senses detect stimuli such as touch, temperature, and pain.

• What are general senses? Senses are distributed throughout the body, including touch, pain, temperature, and proprioception.

• What are not general senses? Special senses like vision, hearing, taste, and smell.

• What senses does motion sickness trigger? Involves vestibular (balance) and visual senses.

Chemistry

Basic Chemical Principles in Physiology

Chemistry underlies all physiological processes, including molecular interactions and the transfer of energy.

• Charge of sub-atomic particles: Protons (+), neutrons (0), electrons (-).

• Ionic bonds: Formed by the transfer of electrons between atoms.

• Covalent bonds: Formed by the sharing of electrons between atoms.

Endocrine System

Hormonal Regulation and Feedback Mechanisms

The endocrine system regulates body functions through hormones secreted by glands.

• Hypothalamic-hypophyseal portal system: A blood vessel system connecting the hypothalamus and pituitary gland, allowing hormone transport.

• Purpose of the adrenal cortex: Produces steroid hormones known as corticosteroids.

• Synergism of hormones: Two or more hormones, when working together, produce an effect greater than the sum of their individual effects.

• Why iodine is essential to hormone function: A Critical building block for thyroid hormones, which the body cannot produce on its own.

• Steroid hormone characteristics: Lipid-soluble, pass through cell membranes, act on intracellular receptors.

• Glucagon and insulin relationship: Glucagon increases blood glucose; insulin decreases it.

Homeostasis

• Hormone response to blood glucose: Insulin is released when blood glucose levels are high; glucagon is released when they are low.

• What happens when your core body temperature decreases? Hormones like thyroxine increase metabolic rate to generate heat.

• Positive feedback loop: A process where the output enhances the original stimulus (e.g., oxytocin in childbirth).

Bone

Structure and Function of the Skeletal System

Bones provide support, protection, and facilitate movement.

• Ossification: The process of bone formation.

• Purpose of the parathyroid gland: Regulates calcium and bone metabolism.

• What characteristic of bone allows the tissue to be resistant to shattering? Collagen fibers provide flexibility and strength.

• Canaliculi: Small channels in bone that connect osteocytes.

• Gomphosis joint examples: A tooth in its socket.

• Sutural bones: Small bones found within cranial sutures.

• Long bone and bone marking characteristics: Long bones have a shaft (diaphysis) and ends (epiphyses); markings include ridges, projections, and depressions.

• Location of meatus: An opening or entrance into a passageway; the external auditory meatus in the ear.

• Endosteum: Membrane lining the inner surface of bone.

• Fibrocartilage: Cartilage containing an abundance of collagen fibers; located around the edges of joints, in the intervertebral discs, and the menisci of the knee.

• Sphenoid bone: A complex bone at the base of the skull.

• Location of atlas: The first cervical vertebra supports the skull.

Muscle

Muscle Tissue Types and Functions

Muscles produce movement, maintain posture, and generate heat.

• Purpose of tendons: Connects a skeletal muscle to an element of the skeleton. Help limit the joint's range of motion and provide mechanical support.

• Four properties of all muscle tissues: Excitability, contractility, extensibility, and elasticity.

• Function of troponin: Regulates muscle contraction by binding calcium.

• Abduction: Movement away from the midline.

• Location of sarcolemma: The plasma membrane of muscle fibers.

• Pronation: The rotation of the forearm that makes the palm face posteriorly.

• Latent period: The time between the stimulation of a muscle and the start of the contraction phase.

• Amphiarthrosis joints: Slightly movable joints.

• Action of gastrocnemius and soleus muscles: Plantar flexion of the foot.

• Complete tetany: Sustained muscle contraction without relaxation.

Nervous System

Peripheral and Central Nervous System Functions

The nervous system controls and coordinates body activities through electrical and chemical signals.

• Purpose of nociceptors: Detecting pain signals

• Parasympathetic nervous system: Promotes rest and digestion.

• Function of medulla oblongata: Controls vital autonomic functions.

• Typical reflex arc: Pathway involving sensory neuron, interneuron, and motor neuron.

• Somatic nervous system: Controls voluntary movements.

• Schwann cell location:

• Nerve that innervates the lateral rectus muscle of the eye: Abducens nerve (cranial nerve VI).

• Inhibitory postsynaptic potential (IPSP) characterization: Hyperpolarizes the postsynaptic membrane, reducing the likelihood of an action potential.

• Function of the posterior or dorsal region of the spinal cord: Transmits sensory information to the brain.

Tissue

Types and Functions of Body Tissues

Tissues are groups of cells with similar structures and functions, forming organs and other body structures.

• Differences between epithelial tissues and connective tissues:

Epithelial tissue- covers exposed surfaces, lines internal passageways and chambers, and produces glandular secretions.

Connective tissue- fills internal spaces, provides structural support, and stores energy.

• Specialized connective tissues: Includes bone, cartilage, blood, and adipose tissue.

• Characteristics of simple cuboidal epithelium: Single layer of cube-shaped cells; functions in secretion and absorption.

• Mesothelium: Lines body cavities; part of serous membranes.

• Fibrocytes: Mature connective tissue cells that maintain the extracellular matrix.

• Perichondrium: Dense layer surrounding cartilage.

Organ Systems

Overview of Major Organ Systems

Organ systems are groups of organs that work together to perform complex functions.

• Which systems transport throughout the body? Circulatory and lymphatic systems.

Cells

Cellular Structure and Function

Cells are the fundamental units of life, performing essential functions that are crucial for survival.

• Cellular organelle used to recycle material: Lysosome; digests and recycles cellular waste.

Integumentary System

Structure and Function of Skin and Associated Structures

The integumentary system protects the body and regulates temperature.

• Protein keratin: Provides strength and waterproofing to skin, hair, and nails.

• Dermis elements: Contains connective tissue, blood vessels, nerves, and glands.

• Function of arrector pili muscles: Causes hair to stand up (goosebumps) in response to cold or fear.

Organism

Body Organization and Terminology

Understanding body planes and directional terms is essential for describing anatomical locations.

• Body planes and directional terms:

  • Sagittal- separates right and left portions.

  • Coronal- separates the anterior and posterior portions of the body. Passing through the skull.

  • Transverse- Horizontal; separates superior and inferior portions of the body.

  • Terms like superior, inferior, anterior, posterior, medial, and lateral.

Summary Table: Main Topics and Specific Ideas