Ch. 15-17 PDF Biology Notes

# Ch.15 ## Voluntary/Involuntary ### SNS vs ANS - **Effectors** (who)- Efferent pathways -Target organ responses (what)- excitatory or inhibitory - **SNS** - Cardiac/smooth muscle, glands - **SNS** - Skeletal muscles - **ANS** - Preganglionic release Ach - **SNS** - Postganglionic r...

# Ch.15 ## Voluntary/Involuntary ### SNS vs ANS - **Effectors** (who)- Efferent pathways -Target organ responses (what)- excitatory or inhibitory - **SNS** - Cardiac/smooth muscle, glands - **SNS** - Skeletal muscles - **ANS** - Preganglionic release Ach - **SNS** - Postganglionic release norepinephrine & Ach - **ANS** - Axons are 2-neuron chain; lightly myelinated, unmyelinated - **SNS** - Heavily myelinated, extend from CNS ➡️ effector - @ preganglionic - @ postganglionic ### Effectors Controlled by the ANS Cardiac/smooth muscle, glands ### # of Neurons in Efferent Pathway of the ANS 2 neurons ### 2 Divisions of ANS - **Sympathetic** (fight or flight) - Ex. ⬆️ heart rate, dilates pupils, inhibits digestion, stimulates sweating - **Parasympathetic** (reset + digest) - Ex. ⬇️ heart rate, constricts pupils, stimulates digestion, promotes urination. ## Efferent Pathway From CNS ➡️ Effector ### Efferent Pathway "Carrying away from" - Signal from CNS travels to an effector (muscle or gland) - Signal moves "away from" CNS ➡️ effector - Motor neurons ### In ANS - Pathway is a 2-neuron chain, preganglionic neuron, postganglionic neuron - Originates in CNS. - Synapses w/ preganglionic before reaching effector # Parts of CNS That Control ANS Brain 🧠 Spinal Cord - Hypothalamus - Brainstem # Main Functions of Parasympathetic NS - **Rest + Digest** - Promotes relaxation, digestion, energy conservation - Lowers heart rate, stimulates digestion, constricts pupils - Allows body to recover # Processes that are Increased by Parasympathetic Stimulation - **SLUD** - Salivation, lacrimation, urination, digestion - Saliva production - Tear production - Contract bladder muscles, urine release - Saliva prod., stomach acid secretion, enzyme release # Main Functions of Sympathetic NS - **Fight or Flight"** - Activate bodily processes that help in dangerous or stressful situations. - ⬆️ heart rate, BP, breathing rate. - Uses norepinephrine # Main Neurotransmitters of ANS Ach, Norepinephrine, Epinephrine (adrenaline) # Ch.16 - 80% smell = taste - Surface of tongue = muscle ## Olfaction - The Sense of Smell - Odrants must be dissolved in the mucus in the nasal cavity to be detected by chemoreceptors. ### Olfactory Epithelium: - Roof of nasal cavity - 3 types: - Olfactory receptor cells: Detect odor-producing molecules (olfactory neurons) - Supporting cells: Sustain the olfactory receptor cells - Basal cells: Replace olfactory receptor cells (neural stem) ### Odors Through Air ➡️ Nasal Mucosa ➡️ Receptors ## Gustation - The Sense of Taste - Occurs when coming in contact w/ taste-producing molecules in what we eat & drink (tastants) - **Gustatory cells** (chemoreceptors) located within taste buds - Tongue + soft palate ### House: - Mechanoreceptors + thermoreceptors ### Papillae of Tongue: - Papillat epithelia + CT elevations on the surface of tongue - **4 types**: - **Filiform**: Short, spiked, no role in gustation; detect texture, manipulate food. - **Fungiform**: Located on tips/sides; blocklike projections, a few taste buds. - **Foliate**: Not well developed, extend as ridges on posterior sides; a few taste buds during infancy & early childhood. - **Vallate**: Least numerous, largest, V shape arrangement, each is surrounded by deep depression, taste buds are within walls along the side. ### Taste Buds: - Cylindrical sensory receptor organs w/ cells - 3 types: - Gustatory cells: Detect taste producing molecules (ions) - Supporting cells: Sustain gustatory cells - Basal cells: Replace the short-lived gustatory cells (neural stem cells) - Travel Back to Brainstem ➡️ Thalamus ➡️ Gustatory **Function (Cranial Nerves)** - Facial (VII) - Glossopharyngeal (IX) - Vagus (X) **5 Basic Taste Sensations** - Sweet - Salt - Sour - Bitter - Umami (savory flavor) ## Visual Receptors: - Uses photoreceptors - Conjunctiva - Epithelial layer, covers surface of sclera + eyelids - Does not cover surface of cornea, no blood vessels interfere w/ passage of light into eye - **Lacrimal apparatus** produces, collects, drains lacrimal fluid. - Contains lysozyme ### Rods & Cones (Photoreceptors) - Rods: - Longer, narrower, located in the peripheral retina, activated by dim light (intensity) - Produce limited sharpness. - Rhodopsin - Cones: - Concentrated in the fovea centralis, high-intensity light. - Provide color recognition + precise visual sharpness (fine detail). - Photopsin # Ch. 16 ## Hearing: How the Ear Regulates Balance - **The Inner Ear's Vestibular System.** - 3 semicircular canals - Sac-like structures = Utricle, Saccule - Moves fluid to stimulate head movement. - Hair cells ## Sensation: - Conscious perception of a stimulus - A stimulus we are consciously aware of - The activation of sensory receptor cells at the level of the stimulus. - Ex. Touching a hot stove (temp receptors in skin detect heat ➡️ sends signals to brain ➡️ Sensation of "burning" or "pain") ## Stimulus + Transducers - **Stimulus** - Change in variable, provokes a cell response. - Internal or eternal environment that triggers a physiological response. - Ex. Light entering the eye ➡️ pupil constricts - Ex. In blood sugar level ➡️ release of hormones to ⬇️ - **Transducer** - Device/organ that converts energy from 1 form to another. - Translates a physical stimulus (pressure, light, sound) into a signal that is interpreted by the NS - Ex. Retina in eye: converts light energy ➡️ electrical signals ➡️ sent to brain for visual perception ## General vs. Special Senses. - **General** - Simple structures distributed throughout the body. - **Somatic Sensory Receptors:** skin + mucous membranes; proprioceptors of joints, muscles, tendons. - **Visceral Sensory Receptors:** walls of internal organs, monitor stretch, chemical environment, temp, pain. - **Special** - Specialized receptors in complex sense organs of the head. - Olfaction - Gustation - Vision - Audition - Equilibrium ## Large Receptors Categories - **Chemoreceptors:** Detect chemicals dissolved in fluid. - Ex. Smell of food, or levels in blood. - External - Internal - **Thermoreceptors:** Detect changes in temp. - Ex. In skin, hypothalamus - **Photoreceptors:** Detect changes in light intensity, color, movement. - Ex. in Retina - **Mechanoreceptors:** Detect distortion of cell membrane. - Touch, Pressure, Vibration, Stretch receptors. - **Nociceptors:** Detect painful stimuli. - **Somatic:** Detect chemical heat or mechanical damage to body surface or skeletal muscles. - **Visceral:** Detect internal organ damage. # Ch.17 ## Function of Endocrine 1. **Regulate Development, Growth, Metabolism**. - Ex. (metabolism) Controlling blood glucose levels - Anabolism - Building of complex molecules - Catabolism - Breakdown of complex molecules 2. **Maintain Homeostasis** 3. **Digestion** - Ex. Secretion of certain enzymes. 4. **Expression of Sexual Behavior (reproductive activities)** - Ex. Prolactin = milk production Oxytocin = reproduction ## Endocrine vs. Nervous - **Endocrine** - Glands secrete hormones in blood. - Proteins (a.a) - Steroids (short polypeptide) - Monomer - Of polypeptide (peptide bonds) - Not necessarily a protein - Slow b/c it has to travel via blood & find its target cell. - Specific receptor group of cells (that receive stimuli) - **Nervous** - Involves neurons = muscles, gland cells. - Localized - certain nerve is connected to a specific spot. - Fast ➡️ neurotransmitter in released into synaptic cleft. - Degradation process of degrading. ## Endocrine Glands - Pituitary - Pineal - Thyroid - Parathyroid - Adrenal ## Effect of Insulin - Hormone - Regulates blood sugar levels - Facilitates the ⬆️ of glucose from bloodstream ➡️ cells throughout the body. ## 3 Types of Hormones + Function 1. **Hormonal:** Binding of 1 hormone activates release of another. - Ex. TSH (pituitary) ➡️ thyroid gland - Thyroid-stimulating hormone 2. **Humoral:** Change in nutrients (glucose), ions (Ca+) - Insulin: Bone development 3. **Nervous:** Direct control of nervous system - Ex. Adrenal medulla ➡️ epinephrine, norepinephrine. ## How Hormones are Stimulated + Released - **3 Types**: Hormonal, Humoral, Nervous. ## Is ACTH Signaling Hormonal, Humoral, or Nervous? - **Nervous** ## Water-Soluble vs. Lipid-Soluble - **Lipid-Soluble:** Diffuse across target cell membrane - Small; nonpolar; lipophilic - In cytosol or nucleus - **Water-Soluble:** Use membrane receptors - Polar; can't diffuse through membrane ## Signaling via Water-Soluble Hormones - NOT getting in - Receptor bound proteins = G proteins - 2nd messenger = cAMP, PLC - GDP ➡️ GTP - Phospholipase C 1. Hormone binds to receptor (ligands). 2. Activates G protein w/ GTP 3. G protein dissociates from receptor. ## The Control of the Levels of Hormones in the Blood - **Pituitary Gland**: Releases hormones that stimulate other endocrine glands to produce specific hormones. - **Negative Feedback**: A hormone level in the blood reaches a threshold ➡️ signal gland to ⬇️ secretion. - ➡️ Hormone level - **Positive Feedback**: Hormone level ⬆️ can trigger hormone release (during childbirth w/ oxytocin) ## 2 Signal Transduction Pathways. - **Water-Soluble Signal Transduction** ➡️ above - **Signal Transduction:** How cells communicate - **2 ways:** - 2nd messenger system - cAMP - PLC = PIP2, DAG, IP3 - Direct gene interaction - ⬆️, ⬇️ in gene activity (transcription) - Steroid results in ⬆️ or ⬇️ ## Growth Hormones & Its Effects - Secreted by cells called **somatotropes**. - Stimulates the **liver** to release **IGF-1** and **IGF-2**. - Stimulate cell growth/division within skeletal + muscular systems. - Controlled through hormonal stimulation by the release of **GHRH** from hypothalamus. ## Primary Target Tissue of GH & IGF - GH: Liver, muscle, bone, adipose tissue; skeletal muscle, liver, bone, cartilage. - IGF - Regulate hormone responses within cells through phosphorylation of target proteins. - Alters activity, gene expression, metabolism ## Upregulation vs. Downregulation - The end result of an effector response. - **Upregulation**: ⬆️ # of receptors - ⬆️ sensitivity to hormone - Occurs when ⬇️ blood levels - Changes in development, cell cycle, cell activity. - **Downregulation**: ⬇️ # of receptors - ⬇️ sensitivity to hormone - Occurs when ⬆️ blood levels - Changes in development, cell cycle, cell activity. - # of receptors on PM influence the degree of response (efficiency, effectiveness, frequency) ## 3 Hormone Interactions 1. **Synergistic**: "working together" - Estrogen + progesterone 2. **Permissive:** 1 hormone requires a 2nd hormone. - TSH ➡️ TH 3. **Antagonistic:** 1 hormone negatively effects a 2nd hormone. ## Effects of Thyroid Hormone: - **Calorigenic effect**: ⬆️ temp. - **Glucose-Sparing effect**: Saves blood glucose for the brain. ## Hyper vs. Hypothyroidism - **Hyperthyroidism**: ⬆️ production of TH - ⬆️ metabolic rate, weight loss, hyperactivity, heat intolerance - **Hypothyroidism**: ⬇️ production of TH. - ⬇️ metabolic rate, feeling cold, weight gain, photophobia. ## Goiter - Enlargement of the thyroid. - Due to insufficient amount of dietary iodine. ## Calcitonin Function: - Inhibits osteoclast activity within bone tissue (the breakdown of bone tissue). - Stimulates the kidneys to ⬇️ the loss of Ca+ in urine. ## 2 Regions of Adrenal Gland 1. **Adrenal Medulla** 2. **Adrenal Cortex** ## Corticosteroids + Function - Corticosteroids ➡️ ⬆️ nutrient levels in blood - Function - Treatment for inflammation. - Resist stress. - Repair injured tissue ## Cushing Syndrome + Addison Disease - **Cushing Syndrome:** Chronic exposure to ⬆️ glucocorticoid hormones in people taking corticosteroids for therapy. - Obesity, hypertension, hirsuitism, kidney stones, menstrual irregularities. - **Addison Disease:** Form of adrenal insufficiency - Develops when adrenal glands fail. - Shortage of glucocorticoids - Lack of ACTH - Weight loss, fatigue, weakness, hypotension, skin darkening. ## Steps of a Stress Response 1. **Alarm Reaction:** - Sympathetic NS activation: ⬆️ - Epinephrine - Norepinephrine 2. **Stage of Resistance**: - Adrenal secretes cortisol to ⬆️ blood sugar 3. **Stage of Exhaustion** - Depletion of fat results in protein breakdown for energy - Weakening of body - Illness -