bio252/6/test

BIO252 Anatomy M06 Exam Study Guide

1. Central and Peripheral Nervous Systems (CNS & PNS)

  • CNS: Composed of the brain and spinal cord; processes and interprets sensory input and sends commands.

  • PNS: Connects the CNS to the body; divided into:

    • Somatic Nervous System: Controls voluntary skeletal muscle movements.

    • Autonomic Nervous System: Controls involuntary functions (smooth muscle, cardiac muscle, glands).

2. Meninges (Brain & Spinal Cord Protection)

Three protective layers:

  1. Dura Mater (Outer, tough)

    • Falx cerebri (between cerebral hemispheres)

    • Tentorium cerebelli (separates cerebrum & cerebellum)

    • Falx cerebelli (separates cerebellar hemispheres)

  2. Arachnoid Mater (Middle, web-like, contains arachnoid villi)

  3. Pia Mater (Inner, delicate, adheres to the brain & spinal cord)

3. Spinal Nerves & Their Components

  • Dorsal Root: Contains sensory neurons entering the spinal cord.

  • Ventral Root: Contains motor neurons exiting the spinal cord.

  • Spinal Nerve: Merging of dorsal & ventral roots (carries sensory & motor signals).

  • White Matter: Myelinated axons transmit information.

  • Gray Matter: Neuron cell bodies, dendrites, unmyelinated axons (processing & regulation).

4. Autonomic Nervous System (ANS)

Sympathetic vs. Parasympathetic Nervous System

Feature

Sympathetic ("Fight or Flight")

Parasympathetic ("Rest & Digest")

Origin

Thoracolumbar (T1-L2)

Craniosacral (CN III, VII, IX, X, S2-S4)

Neurotransmitter

Norepinephrine (NE)

Acetylcholine (ACh)

Ganglia Location

Near spinal cord

Near/in target organ

Receptors

Alpha (\u03b1) & Beta (\u03b2)

Nicotinic & Muscarinic

5. Brain Anatomy & Function

Cerebrum (Largest brain region)

  • Left Hemisphere: Language, math, analytical skills.

  • Right Hemisphere: Spatial awareness, creativity, pattern recognition.

Lobes of the Cerebrum

Lobe

Function

Frontal

Reasoning, problem-solving, emotions

Parietal

Sensory processing (touch, temperature, pain)

Temporal

Auditory processing, memory, language

Occipital

Visual processing

Insular

Emotion, taste, visceral sensations

Brainstem Functions

  • Midbrain: Vision, hearing, motor control.

  • Pons: Regulates breathing, relays signals.

  • Medulla Oblongata: Controls heart rate, blood pressure.

Cerebellum: Coordinates muscle movements, posture, balance.

6. Cranial Nerves

Mnemonic: "Oh Oh Oh To Touch And Feel Very Green Vegetables Ah Heaven"

#

Cranial Nerve

Function

I

Olfactory

Smell

II

Optic

Vision

III

Oculomotor

Eye movements, pupil constriction

IV

Trochlear

Eye movements

V

Trigeminal

Facial sensation, chewing

VI

Abducens

Eye movements

VII

Facial

Facial expressions, taste

VIII

Vestibulocochlear

Hearing, balance

IX

Glossopharyngeal

Swallowing, taste

X

Vagus

Autonomic functions (heart, lungs, digestion)

XI

Accessory

Shoulder & neck movements

XII

Hypoglossal

Tongue movements

7. Sensory Receptors

Types & Functions

Receptor Type

Function

Mechanoreceptors

Detect pressure, touch, vibration

Baroreceptors

Detect pressure in blood vessels & organs

Proprioceptors

Detect body position & movement

Thermoreceptors

Detect temperature changes

Nociceptors

Detect pain or harmful stimuli

Photoreceptors

Detect light (rods & cones in retina)

Chemoreceptors

Detect chemical stimuli (taste, smell)

8. Olfactory & Gustatory Pathways

Olfactory (Smell) Pathway:

  1. Odor molecules bind to olfactory receptor proteins in nasal epithelium.

  2. Signal travels via olfactory neurons through cribriform plate.

  3. First synapse at olfactory bulbs.

  4. Signal relayed via olfactory tract to olfactory cortex, hypothalamus, limbic system (triggers emotions).

Gustatory (Taste) Pathway:

  1. Chemicals bind to gustatory cells in taste buds.

  2. Signals transmitted via:

    • Facial Nerve (CN VII): Anterior 2/3 of tongue

    • Glossopharyngeal Nerve (CN IX): Posterior 1/3 of tongue

    • Vagus Nerve (CN X): Pharynx

  3. Signal travels to medulla oblongata, then thalamus, and finally to insula (gustatory cortex).

9. Key Terms & Concepts

  • Neuron Types: Multipolar, bipolar, unipolar, anaxonic.

  • Neuroglial Cells: Oligodendrocytes, Schwann cells, astrocytes, microglia, ependymal cells.

  • Synapse Components: Presynaptic neuron, synaptic cleft, postsynaptic neuron.

  • Neurotransmitters: Acetylcholine (ACh), Norepinephrine (NE), GABA, Serotonin