Honors Anatomy & Physiology – 2nd Semester Final Study Guide

Ch. 12 - Nervous System/Neural Tissue

• Functions of the Nervous System:

  • Sensory Input: Detects internal and external stimuli.

  • Integration: Formulates appropriate responses using interneurons and complex neural circuits.

  • Motor Output: Efferent neurons transmit signals from the CNS.

• CNS vs. PNS:

  • Central Nervous System (CNS): Brain and spinal cord; processes sensory information, coordinates motor commands, and performs higher functions like learning.

  • Peripheral Nervous System (PNS): Delivers sensory information to the CNS and carries out motor commands.

• Function and Divisions of the PNS:

  • Function: Delivers sensory information to the CNS and carries out motor commands.

  • Divisions:

    • Afferent Division: Transmits sensory information to the CNS.

    • Efferent Division: Carries out motor commands from the CNS.

• Organization of the Nervous System:

  • Central Nervous System: Brain and spinal cord.

  • Peripheral Nervous System: All neural tissues outside the CNS.

    • Afferent

    • Efferent

      • Somatic

      • Autonomic

• Neuroglia and Their Functions:

  • Ependymal cells: Line the central canal of the spinal cord; secrete and circulate cerebrospinal fluid.

  • Astrocytes: Maintain the blood-brain barrier and provide structural support.

  • Oligodendrocytes: Provide myelination for the CNS.

  • Microglia: Clean up cellular debris, waste products, and pathogens.

  • Satellite cells: Regulate the environment around neurons.

  • Schwann cells: Form the myelin sheath.

• Parts of a Neuron:

  • Cell body

  • Dendrites

  • Axon

  • Synaptic terminals

• Functions of Axons and Dendrites:

  • Axons: Transmit action potentials.

  • Dendrites: Receive synaptic inputs from other neurons and transmit electrical signals to the cell body.

• Functions of Schwann Cells and Nodes of Ranvier:

  • Schwann cells: Provide insulation that increases the speed of action potential propagation.

  • Nodes of Ranvier: Gaps in the myelin sheath where action potentials are regenerated.

• Locations and Functions of Interneurons, Sensory Neurons, and Motor Neurons:

  • Interneurons: Located in the CNS; integrate sensory and motor information and are involved in higher functions of learning and memory.

  • Sensory Neurons: Located in the PNS; transmit sensory information from receptors to the CNS.

  • Motor Neurons: Located in the PNS; carry out motor commands from the CNS.

• Resting Membrane Potential:

  • Maintained by the sodium-potassium ATPase pump, which carries 3 Na+ out and 2 K+ in, balancing the passive forces of diffusion.

  • Resting potential: $-70 \, mV$

• Action Potential Generation:

  1. Depolarization to Threshold

  2. Activation of $Na^+$ channels

  3. Inactivation of $Na^+$ channels and activation of $K^+$ channels

• Synaptic Transmission:

  1. Action Potential Arrival: An action potential depolarizes the synaptic terminal.

  2. Calcium Influx: Extracellular $Ca^{2+}$ enters the synaptic terminal, triggering the exocytosis of acetylcholine (ACh).

  3. ACh Binding: ACh binds to receptors on the postsynaptic membrane, depolarizing it.

  4. ACh Removal: ACh is removed by acetylcholinesterase (AChE).

• Absolute Refractory Period:

  • No action potential is possible because $Na^+$ channels are open or inactivated.

• Threshold Stimulus:

  • A depolarization large enough to change the resting membrane potential $-70 \, mV$ to the threshold level of voltage-gated $Na^+$ channels $-55 \, mV$.

• All-or-None Principle:

  • If the stimulus increases threshold, an action potential is triggered.

• Synapse:

  • One neuron communicates with another cell.

• Synaptic Transmission

Ch. 13-14 - Central Nervous System Brain

• Major Regions of the Adult Brain:

  • Cerebrum

  • Cerebellum

  • Diencephalon

  • Midbrain

  • Pons

  • Medulla oblongata

• Major Lobes, Fissures, and Functional Areas of the Cerebral Cortex:

  • Lobes: Frontal, parietal, temporal, occipital

  • Fissures: Longitudinal fissure separates the cerebral hemispheres.

  • Functional Areas:

    • Precentral gyrus: Coordinates voluntary movement.

    • Postcentral gyrus: Receives somatic sensory information.

    • Special Sensory Cortexes: visual, auditory, olfactory, and gustatory cortex

• General Function of the Basal Nuclei:

  • Direct subconscious activities, such as the subconscious control of skeletal muscle tone and coordination of learned movement patterns.

• Location and Function of the Diencephalon:

  • Integrates sensory information and motor commands.

  • Subdivisions: Thalamus, epithalamus, and hypothalamus

• Location and Function of Thalamus, Hypothalamus, and Epithalamus:

  • Thalamus: Filters ascending sensory information for the primary sensory cortex and relays information between the basal nuclei and cerebral cortex.

  • Hypothalamus: Controls autonomic functions, coordinates activities of the nervous and endocrine systems, secretes hormones, produces emotions and behavioral drives, regulates body temperature, and controls circadian rhythms.

  • Epithalamus: Contains the pineal gland, which secretes melatonin and regulates day-night cycles

• Three Major Areas of the Brain Stem and Their General Functions:

  • Midbrain: Processes sight, sound, and associated reflexes; maintains consciousness.

  • Pons: Connects the cerebellum to the brain stem and is involved in somatic and visceral motor control.

  • Medulla Oblongata: Connects the brain to the spinal cord, relays information, and regulates autonomic functions like heart rate, blood pressure, and respiratory rate.

• Structure and Function of the Cerebellum:

  • Coordinates repetitive body movements.

  • Two hemispheres covered with a cerebellar cortex.

  • Adjusts postural muscles and fine-tunes conscious and subconscious movements.

• Limbic System:

  • Establishes emotional states.

  • Links conscious functions of the cerebral cortex with autonomic functions of the brain stem.

  • Facilitates memory storage and retrieval

• Protection of the Brain:

  • Meninges: The spinal meninges protect the spinal cord, carry blood supply, and are continuous with cranial meninges.

  • Cerebrospinal Fluid: Cushions delicate neural structures, supports the brain (buoyancy), and transports nutrients, chemical messengers, and waste products.

  • Meningitis: Inflammation of the meninges, often caused by a virus or bacteria.

• Layers of Meninges and Their Roles:

  • Dura Mater: The outer layer, tough and fibrous.

  • Arachnoid Mater: The middle layer, with interlayer spaces.

  • Pia Mater: The inner layer, bound to underlying neural tissue and containing blood vessels.

Ch. 18 - Blood

• Components of Blood and Their Relative Proportions:

  • Plasma: 46-63% of whole blood

  • Formed Elements: 37-54%

• Physical Characteristics of Blood:

  • Temperature: $38^\circ C$ ($100.4^\circ F$)

  • High viscosity

  • Slightly alkaline pH: 7.35–7.45

  • Volume: 4-6 liters in adults (about 7% of body weight)

• Functions of Blood:

  • Transport of gases, nutrients, hormones, immune components, and waste products.

  • Regulation of pH, ion concentrations.

  • Fluid loss at injury sites.

  • Defense against toxins and pathogens.

  • Stabilizing body temperature

• Blood Plasma:

  • Fluid component of blood, making up 50-60% of blood volume.

  • Over 90% water

  • Contains nutrients, salts (ions), respiratory gases, hormones, proteins, and waste products

• Major Proteins in Blood Plasma:

  • Albumins (60%): Transport fatty acids, thyroid hormones, and steroid hormones; regulate osmotic pressure.

  • Globulins (35%): Include antibodies (immunoglobulins) that are crucial for immune defense.

  • Fibrinogen (4%): Helps form clots by producing long, insoluble strands of fibrin.

• Formed Elements of the Blood:

  • Red blood cells (RBCs) (Erythrocytes): Transport oxygen and carbon dioxide; small, biconcave discs containing hemoglobin.

  • White blood cells (WBCs) (Leukocytes): Part of the immune system, defending against pathogens, removing toxins, and attacking abnormal cells.

  • Platelets (Thrombocytes): Cell fragments involved in clotting.

• Roles of Different White Blood Cells:

  • Neutrophils: Attack bacteria and are phagocytic.

  • Eosinophils: Attack large parasites and respond to allergies.

  • Basophils: Initiate inflammation in damaged tissue

  • Monocytes: Engulf large particles and pathogens (macrophages).

  • Lymphocytes: Part of the body’s specific defense system (immune response).

• Breakdown of Erythrocytes:

  • Erythrocytes are monitored and engulfed by macrophages in the liver and spleen before their membranes rupture (hemolyze).

  • Hemoglobin is then recycled.

• Disorders of Blood Cell Count:

  • Leukopenia: Abnormally low WBC count (below 4,000/μL).

  • Leukocytosis: Abnormally high WBC count (around 15,000/μL to 50,000/μL).

  • Leukemia: Extremely high WBC count (above 100,000/μL).

  • Thrombocytopenia: Abnormally low platelet count (below 80,000/μL).

  • Thrombocytosis: Abnormally high platelet count (above 1,000,000/μL).

• Hemostasis:

  • The process of stopping bleeding.

• Platelet Plug Formation:

  • Begins within 15 seconds after injury.

  • Platelets adhere to the damaged vessel wall and aggregate, forming a plug that closes small breaks.

• Human Blood Groups:

  • Determined by the presence or absence of specific surface antigens on RBCs.

  • The ABO and Rh systems are clinically significant.

  • The presence or absence of RBC surface antigens A, B, and Rh (D) determine each blood group.

• Antigens (Agglutinogens):

  • Surface proteins on RBCs that identify cells to the immune system.

• Antibodies (Agglutinins):

  • Plasma proteins that attack and agglutinate foreign antigens

• Transfusion Reaction:

  • Occurs when antibodies meet their specific surface antigen, causing agglutination and hemolysis of the blood.

  • Blood typing is used to ensure donor and recipient blood types are compatible, avoiding such reactions.

  • Agglutination: Clumping of red blood cells (RBCs) when antibodies bind to antigens on the surface of the RBCs.

  • Hemolysis: Destruction or rupture of red blood cells, leading to the release of hemoglobin into the surrounding fluid.

• Physical Characteristics of Red Blood Cells:

  • Small, highly specialized biconcave discs.

  • As they move through small blood vessels, they form stacks called rouleaux.

• Hemopoiesis:

  • Production of formed elements.

• Erythropoiesis:

  • Formation of RBCs

• Hemocytoblasts:

  • Stem cells in myeloid tissue that divide to produce all types of blood cells.

Ch. 19-20 - Cardiovascular System

• Protection of the Heart:

  • The heart is surrounded and stabilized by the pericardial sac.

• Layers of the Heart Wall:

  • Epicardium: Covers the heart (visceral pericardium).

  • Myocardium: Muscular wall of the heart.

  • Endocardium: Inner layer; made of endothelium.

• Structure and Function of the Four Heart Chambers:

  • Right Atrium: Collects deoxygenated blood from the systemic circuit.

  • Right Ventricle: Pumps deoxygenated blood to the pulmonary circuit.

  • Left Atrium: Collects oxygenated blood from the pulmonary circuit.

  • Left Ventricle: Pumps oxygenated blood to the systemic circuit.

• Heart Chambers and Associated Great Vessels:

  • Right Atrium: Superior and Inferior Vena Cava, Coronary Sinus

  • Right Ventricle: Pulmonary Trunk

  • Left Atrium: Pulmonary Veins

  • Left Ventricle: Aorta

• Heart Valves:

  • Atrioventricular (AV) Valves: Located between the atria and ventricles; controlled by chordae tendineae and papillary muscles. They open when ventricles are relaxed.

  • Semilunar (SL) Valves: Located between the ventricles and arteries; controlled by pressure; have three semilunar cusps. They are closed when ventricles are relaxed

• Conduction System of the Heart:

  • Components:

    • Sinoatrial (SA) Node

    • Atrioventricular (AV) Node

    • Conducting Cells (AV bundle → bundle branches → Purkinje fibers)

  • Conduction Pathway:

    • SA Node → AV Node → AV Bundle → Bundle Branches → Purkinje Fibers

• Normal Electrocardiogram:

  • P Wave: Atrial depolarization.

  • QRS Complex: Ventricular depolarization.

  • T Wave: Ventricular repolarization

• Layers of a Blood Vessel Wall:

  • Tunica Intima: Innermost layer; endothelium.

  • Tunica Media: Middle layer; smooth muscle.

  • Tunica Externa: Outermost layer; collagen and elastic fibers.

• Blood Pressure:

  • Hypertension: Abnormally high blood pressure.

  • Hypotension: Abnormally low blood pressure

• Cardiac Cycle Phases:

  • Systole: Contraction phase.

  • Diastole: Relaxation phase

Ch. 22 – Respiratory System

• Structures of the Respiratory System:

  • Upper Respiratory System:

    • Nose

    • Nasal cavity

    • Nasal conchae

    • Internal nares

    • Pharynx (nasopharynx, oropharynx, laryngopharynx)

    • Frontal sinus

    • Sphenoidal sinus

  • Lower Respiratory System:

    • Larynx

    • Trachea

    • Bronchus (right and left)

    • Bronchioles

    • Lungs (right and left)

    • Diaphragm

  • Functions: Air movement, gas exchange, protection, sound production, and olfaction

• Structures In and Around the Nasal Cavity:

  • nose external nares (nostrils)

  • nasal vestibule (with nasal hairs for filtration)

  • nasal cavity

  • nasal septum

  • olfactory region

  • nasal conchae

• Parts of the Pharynx:

  • Nasopharynx: Superior portion, mainly for air passage; contains pharyngeal tonsils.

  • Oropharynx: Middle portion, for both food and air passage.

  • Laryngopharynx: Inferior portion, extending from the hyoid bone to the larynx and esophagus

• Site of Gas Exchange:

  • The alveoli are the air-filled pockets where gas exchange occurs

• Pulmonary Embolism:

  • A blockage of pulmonary vessels, often by blood clots, fat, or air bubbles

• External and Internal Respiration: *External respiration: Exchange of oxygen and carbon dioxide with the environment, including pulmonary ventilation, gas exchange in the lungs, and gas transportation in the bloodstream.

  • Three phases of external respiration:

    • Pulmonary ventilation (breathing)

    • Gas exchange in the lungs

    • Transportation of gases in the bloodstream.

  • Internal respiration: Uptake of oxygen and release of carbon dioxide by cells within the body.

• Differences Between the Left and Right Lungs:

  • Right lung: Three lobes, wider, and displaced upward by the liver.

  • Left lung: Two lobes, longer, and has a cardiac notch to accommodate the heart.

Diagrams To Know:

• Neuron (12-7)

• Heart (19-8)

• Brain Region (13-6)

Important Concepts:

• How blood flows through the heart and body (including valves and circuits)

• How conduction differs between myelinated and unmyelinated neurons, both in terms of velocity and how it travels.

• How alveoli and diffusion allow for gas exchange to occur in the lungs.

  • Damage to Respiratory Epithelium: Smoking damages the ciliated pseudostratified columnar epithelium that lines the respiratory tract Ch. 22 - Respiratory System (Current).pptx (Page 8). This impairs the ability to clear mucus and debris, leading to increased risk of infection and inflammation.

  • Alveolar Damage: The chemicals in cigarette smoke can destroy the elastic fibers in the alveoli, reducing their ability to expand and contract properly Ch. 22 - Respiratory System (Current).pptx (Page 20). This leads to conditions like emphysema, where the alveoli lose their structure and gas exchange becomes less efficient.

  • Reduced Gas Exchange: The overall effect is a reduction in the surface area available for gas exchange, making it harder to get oxygen into the blood and remove carbon dioxide.

    Couple of specific ways in which the Nervous, Cardiovascular/Circulatory, and Respiratory systems are directly interrelated to each other in their functioning.

  • Nervous System Control of Breathing: The nervous system controls the rate and depth of breathing, which directly impacts gas exchange in the respiratory system. The medulla oblongata in the brain stem regulates respiratory rate based on blood CO2​ and O2​ levels, ensuring the cardiovascular system receives properly oxygenated blood Ch. 13-14 Notes - Current.pptx (Page 60).

  • Cardiovascular System's Role in Gas Transport: The cardiovascular system transports oxygen from the lungs (supplied by the respiratory system) to the body's tissues and carries carbon dioxide back to the lungs for exhalation. This transport is crucial for cellular respiration and overall metabolic function Ch. 19-20 Notes.pptx (Page 5).
    - Respiratory System Provides Oxygen: The respiratory system brings in oxygen, which the cardiovascular system then transports to cells. Without the respiratory system's gas exchange, the cardiovascular system would have no oxygen to deliver Ch. 22 - Respiratory System (Current).pptx (Page 2).

  • Respiratory System Removes Carbon Dioxide: The respiratory system eliminates carbon dioxide, a waste product of cellular metabolism, which is transported from the tissues to the lungs by the cardiovascular system. This prevents the buildup of toxic levels of CO2​ in the body Ch. 22 - Respiratory System (Current).pptx (Page 2).

• Anything covered in 2nd Semester is fair game for the Final. Make sure to review vocab quizzes, labs, and notes.