AP2 Exam 1 Lab - Reflexes and Sensory Systems PDF

\*\*Reflexes: Rapid Motor Responses\*\* \- Two main types: 1\. \*\*Autonomic reflexes\*\* \[1\] \- Stimulate smooth muscles, cardiac muscle, glands \- Often unconscious (e.g., digestion, blood pressure changes) 2\. \*\*Somatic reflexes\*\* \[1\] \- Stimulate skeletal muscles \- Often tested i...

\*\*Reflexes: Rapid Motor Responses\*\* \- Two main types: 1\. \*\*Autonomic reflexes\*\* \[1\] \- Stimulate smooth muscles, cardiac muscle, glands \- Often unconscious (e.g., digestion, blood pressure changes) 2\. \*\*Somatic reflexes\*\* \[1\] \- Stimulate skeletal muscles \- Often tested in medical exams \*\*Reflex Arc Components\*\* \[2\] 1\. Sensory Receptor 2\. Sensory neuron 3\. Integration center 4\. Motor neuron 5\. Effector \*\*Types of Reflex Arcs\*\* \[3\] \- Monosynaptic: Single synapse between sensory & motor neuron \- Polysynaptic: One or more interneurons between sensory & motor neurons \*\*Common Spinal Somatic Reflexes\*\* \[4\] \- Stretch reflexes (e.g., Patellar tendon reflex) \- Crossed-extensor reflex \- Superficial reflexes (e.g., Plantar reflex) \*\*Autonomic Reflexes\*\* \[5\] \- Many types exist \- Pupillary light reflex is commonly tested \- Causes pupil constriction in response to bright light \- Consensual reflex: Both pupils constrict when light shines in one eye \*\*Overview of Sensory Systems\*\* \- \*\*Sensory Receptors\*\*: Specialized to respond to environmental stimuli \[1\] \- Classified by: 1\. Type of stimulus (e.g., mechanoreceptor, thermoreceptor) 2\. Body location (e.g., exteroceptor, interoceptor) 3\. Structural complexity (general vs. special senses) \*\*General Senses\*\* \- \*\*Receptor Physiology\*\*: \- Tactile localization: Brain\'s ability to determine touched skin areas \- Adaptation: Decreased awareness of continuous stimuli \- Referred pain: Pain perceived in a different location from its source \[2\] \*\*Special Senses\*\* 1\. \*\*Vision\*\* \- External anatomy: Includes eyelids, lacrimal apparatus, conjunctiva \- Eye structures: Sclera, cornea, iris, pupil, lens, retina \- Extrinsic muscles: 4 rectus and 2 oblique muscles \[3\] 2\. \*\*Hearing\*\* \- External ear: Auricle, external auditory canal, tympanic membrane \- Middle ear: Auditory ossicles, auditory tube \- Inner ear: Cochlea, vestibule, semicircular canals \[4\] 3\. \*\*Smell (Olfaction)\*\* \- Olfactory epithelium in superior nasal cavity \- Olfactory receptors: Modified neurons with cilia \[5\] 4\. \*\*Taste (Gustation)\*\* \- Taste buds on tongue papillae \- Four types of papillae: Vallate, Fungiform, Foliate, Filiform \- Gustatory receptors for different taste sensations \[5\] \*\*Note\*\*: This summary covers the main points of the sensory systems described in the document, focusing on their structures and functions. \*\*Brain and Nervous System Overview\*\* \- \*\*Nervous System Divisions\*\* \[1\] \- Central Nervous System (CNS): Brain and spinal cord \- Peripheral Nervous System (PNS): All nervous tissue outside CNS \- \*\*Major Brain Regions\*\* \[2\] 1\. Cerebrum 2\. Diencephalon 3\. Cerebellum 4\. Brain stem \*\*Cerebrum\*\* \- Functions: Conscious thought, intelligence, sensory and motor processing \[3\] \- Divided into two hemispheres connected by corpus callosum \- Surface features: \- Gyri (ridges) and sulci (grooves) \- Cerebral cortex (gray matter) on the outside, white matter inside \- Four lobes: \[4\] \- Frontal: Decision making, planning, muscle control \- Parietal: Sensory processing \- Temporal: Hearing \- Occipital: Vision \*\*Diencephalon\*\* \- Key structures: \[5\] 1\. Thalamus: Sensory relay station 2\. Hypothalamus: Homeostasis regulation 3\. Epithalamus: Contains pineal gland \*\*Brain Stem\*\* \- Components: \[5\] 1\. Midbrain: Visual and auditory reflexes 2\. Pons: Information relay 3\. Medulla oblongata: Autonomic functions \*\*Cerebellum\*\* \- Functions: Regulates posture, balance, and coordinates muscle movements \[5\] \- Structure: Two hemispheres connected by vermis, with internal white matter (arbor vitae) \*\*Other Brain Features\*\* \- Meninges: Protective layers (dura mater, arachnoid mater, pia mater) \[5\] \- Ventricles: Cavities filled with cerebrospinal fluid (CSF) \*\*Cranial Nerves\*\* \- 12 pairs, part of PNS, serving mainly head and neck \[5\] \- Functions include sensory and motor control for various facial and bodily processes \*\*Spinal Cord Anatomy\*\*: \- Extends from foramen magnum to L1/L2 vertebrae \- Covered by meninges: dura mater, arachnoid mater, pia mater \- 31 spinal nerves arise from the cord \- Anchored by denticulate ligaments and filum terminale \- Divided into gray matter (central) and white matter (outer) \*\*Spinal Nerves\*\*: \- 31 pairs formed by fusion of ventral and dorsal roots \- Exit through intervertebral foramina \- Form plexuses: cervical, brachial, lumbar, and sacral \*\*Major Nerve Plexuses\*\*: \- Cervical (C1-C5): supplies shoulder, neck, chest, scalp \- Key nerve: Phrenic nerve (diaphragm) \- Brachial (C5-T1): supplies upper limb \- Key nerves: Axillary, Musculocutaneous, Median, Ulnar, Radial \- Lumbar (L1-L4): supplies lower limb \- Key nerves: Femoral, Obturator \- Sacral (L4-S4): supplies lower limb and perineum \- Key nerves: Sciatic, Pudendal \*\*Important Structures\*\*: \- Conus medullaris: cone-shaped end of spinal cord \- Cauda equina: collection of nerve roots below spinal cord \- Epidural space: between dura mater and vertebrae, used for anesthesia \[1\]\[2\]\[3\]