Exam 1 Flashcards
What domains are living organisms classified under?
Archaea, bacteria, and eukaryotes
What are eukaryotes?
Single or multi-cellular organisms with nuclei
What are the characteristics of animals?
Multicellular, breathe oxygen and have mitochondria, motile and heterotrophic, sexual reproduction, advanced sensory and circulatory systems, and development begins with the formation of a blastula
How many species are there in the animal kingdom?
1.5 million
What is animal anatomy?
The study of animal body structures
What is animal physiology?
The study of normal animal functions
What is homeostasis?
Maintaining a stable physiology or equilibrium in a constantly changing environment
What are the phases from zygote to blastula?
Zygote, 2-cell stage, 4-cell stage, morula, and blastula
What is the ectoderm?
The epidermis of skin and its derivatives (sweat glands, hair follicles), includes the nervous system
What is the mesoderm?
Notochord, skeletal system, muscles, circulatory and lymphatic system, reproductive system, dermis of skin, lining of body cavity, and adrenal cortex
What is the endoderm?
Epithelial lining of the digestive tract, epithelial lining of the respiratory system, lining of the urethra, bladder, and reproductive system, the liver, the pancreas, the thymus, and the thyroid and parathyroid glands
What makes up the cell lipid barrier?
Phospholipids, cholesterol, and proteins
What is contained within the cell cytoplasm?
Organelles, structural proteins, intracellular signaling, and glycolysis
What happens within the nucleus?
DNA and genetic code are stored, mRNA transcription
What happens within the mitochondria?
Oxidative phosphorylation and steroid production
What happens within the endoplasmic reticulum?
Ribosome are stored, mRNA translation, and calcium storage
What happen in the golgi apparatus?
Protein processing and packaging
What are vesicles or granules?
Contains materials for cell bulk transport into and out of the cell
What is exocytosis?
Material is released into extracellular space by budding of small vesicles from the cell membrane
What is endocytosis-pinocytosis?
Absorption of extracellular components into the cell by budding of small vesicles from the cell membrane
What is endocytosis-phagocytosis?
Ingestion of large material, including other cells, by specialized cells
What are microvilli?
Membrane extensions that increase cell surface area for secretion and absorption, particularly for epithelial cells
What are cilia?
Large membrane-protein extensions that can use ATP to beat or move. Used by the cell to move contents, sense vibrations, or fluid movement in the animal body.
What is the animal cell chemical composition?
Water, protein, lipid, carbohydrates, and inorganic solutes
How much water is in cells?
60%
Where do animals get amino acids and what are they used for?
From diet or synthesized in cell, can be used as a form of energy.
What are proteins?
Polypeptides that form 3D structures, function affected by pH and temperature
What are the functions of proteins?
Enzymes, hormones, receptors, cell structure, and transport
What are monosaccharides?
Simple sugars, Glucose is the most prevalent in the body
What are two examples of disaccharides?
Lactose and maltose
What is glycogen and where is it produced?
Long chains of glucose, produced in the liver and muscle
What are starch and cellulose?
Long chains of glucose found in plants and used by plants for energy and structure.
How many deoxyribose units are in each cell?
12 billion
What are inorganic solutes?
Ions that makeup 1% of the cell. ex: potassium, sodium, chloride, phosphate, and bicarbonate
What is an electrolyte?
A molecule that dissolves into individual ions in a solution
What are fatty acids?
Chains of carbon and hydrogen (hydrocarbons)
What are properties of fatty acids?
They can form triglycerides, and they can be modified into ligands/hormones.
What are triglycerides?
Glycerol + 3 fatty acids. Stored as fat and used for energy
What are phospholipids and where are they found?
Phosphate group + 2 fatty acids. Found in the cell, nuclear, and mitochondrial membranes
What is cholesterol?
A component of the cell membrane, can be converted to steroids.
What are the functions of membrane proteins?
Cell adhesion and transport, cell communication and enzyme activity, structure, and cell recognition by immune cells.
What are desmosomes?
Proteins that cause cell adherence
What are tight junctions?
Proteins that help form a tight barrier. important for epithelial cells.
What are gap junctions?
Proteins that aid in cell-to-cell communication. important for smooth and cardiac muscle synchronous contraction.
How to gap junctions work?
Connexin proteins form a passageway between two cells for molecule sharing and transport
What is a chemical gradient?
When the concentration of a molecule or solute is greater on one side of the membrane.
What is an electrical gradient?
When electrical charges are separates by the cell membrane.
What is an electrochemical gradient?
When a molecule or solute has both an electrical and chemical gradient.
What does the animal cell use electrochemical gradients for?
To do work
How do molecules diffuse?
From an area of high concentration to low concentration
What is the charge of an animal cell?
Negative
What is osmosis?
The movement of water across a permeable membrane toward an are of lower water concentration and a greater concentration of solutes.
What is an isotonic solution?
Having the same solute or osmotic pressure inside and outside the cell. This is normally 300 mOsm
What is a hypotonic solution?
When there is a higher solute concentration inside the cell, and a lower concentration outside.
What is a hypertonic solution?
When the solute concentration outside the cell is higher than the inside of the cell.
What is unassisted membrane transport?
Passive transport
What is assisted membrane transport?
Membrane proteins assist and control the movement of molecules across the cell membrane
What is passive diffusion?
Diffusion driven by chemical gradients, generally small, uncharged molecules. ex: oxygen, carbon dioxide, and water.
How is assisted membrane transport achieved?
With the help of cell membrane transporters called channels or carriers. The electrochemical gradient still drives diffusion. Some carriers use ATP to drive molecules against the gradient.
What are channels?
Proteins that transport ions such as Na+, K+, Ca+, Cl-, or water (passive transport).
What are leak channels?
Channels that are always open
What are voltage gated channels?
Channels that open in response to change in the cell membrane electrical charge. Can also be activated by physical or chemical stimuli.
How do molecules always flow?
Down an electrochemical gradient
What are aquaporin channels?
Water channels that transport billions of water molecules per second into the cell. Mammals have 13 different types.
What are carriers?
Proteins that transport molecules across the cell membrane using “flip-flop “activity.
What is a symporter?
A carrier that transports different molecules across the membrane in the same direction.
What is an antiporter
A carrier that transports different molecules across the membrane in the opposite direction.
What is facilitated transport?
When a molecules flows down a gradient and does not require ATP
What is active transport?
A molecules is pumped up a gradient and requires ATP
What is primary active transport?
The carrier uses ATP directly to transport the molecule.
What is the Sodium-Potassium ATPase pump?
A major animal cell primary active transporter. 3 Na+ out and 2 K+ into the cell, against gradients. Helps to establish a negative charge inside the cell membrane and maintain osmotic equilibrium.
What is secondary active transport?
When ATP is required to transport the molecule but ATP is not directly used by the carrier.
What does the rate of transport depend on?
The number of carriers present in the cell membrane
What is membrane potential?
The difference in electrical charge across the cell membrane in millivolts
What is the resting membrane potential?
The resting charge along the inside of the cell membrane when the cell is at “rest”
What is threshold potential?
The minimal membrane charge that can trigger an irreversible flow of positive charged ions into the cell through voltage gated channels
What is action potential?
Rapid, short lived, changes in membrane charge so that the inside of the cell becomes more positive (depolarization).
What are action potentials triggered by?
Physical, chemical, or electrical stimuli.
What does action potential allow?
It allows the cell to do work such as contract or release ligands/hormones or neurotransmitters.
What is action potential essential for?
Muscle and nervous tissue function
What process/steps happens during action potential?
- Resting potential
- Voltage gated Na+ channels open
- Na+ rapidly enters cell
- At peak action potential, Na+ channels close and voltage gated K+ channels open.
- K+ leaves cell, causing repolarization to resting potential
- Na+ channels are closed but capable of reopening
- Further movement of K+ briefly hyperpolarizes the cell membrane
- K+ channels close, and the membrane returns to resting potential
What is intracellular signaling?
Signaling that occurs between cells by direct cell-to-cell contact (gap junctions and juxtracrine signaling)
What is extracellular signaling?
When signaling molecules are secreted into the extracellular space for cell-to-cell communication (paracrine and autocrine signaling)
What is a neurotransmitter?
A ligand that is secreted by a neuron or signals to a neuron (paracrine signaling).
What is endocrine signaling?
A ligand is secreted into the blood vessels for long-distance cell-to-cell communication
What is a ligand called when it is secreted into the blood?
A hormone
What is neuroendocrine signaling?
A ligand is secreted by a neuron into the blood.
What is a pheromone?
A ligand that is secreted outside the animal body for communication with a different animal.
Where are receptors for large ligands found?
In the cell membrane
What do ligands activate?
Intracellular enzyme cascades
What is the most common type of cell membrane receptor?
7-membrane domain receptor (7TMDR)
Where are receptors for small or lipophilic ligands such as steroids found?
Inside the cell cytoplasm (may take hours or days)
What is saturation?
When receptors become saturated
What is specificity?
Receptors typically bind to a specific molecule
What are antagonists of ligands?
A molecule that blocks the function of a ligand.
What are agonists of ligands?
A molecule that contributes to the function of the ligand. Usually involves binding of a molecule to the ligands receptor, activating it.
What are the types of animal muscle?
Skeletal, smooth, and cardiac
What are the functions of skeletal muscle?
Moves and stabilizes animal limbs and joints, contraction is consciously or voluntarily controlled (mostly), striated with organized proteins for contraction, stores glucose, helps animal breathe, helps return blood to the heart, and generates heat.
What is type 1 skeletal muscle?
Slow twitch, red appearance, slower to contract but can contract for longer periods of time (high endurance muscle).
What is type 2 skeletal muscle?
Fast twitch, pale appearance, faster to contract but cannot maintain contraction for long periods of time (considered low endurance muscle).
What is a muscle?
Bundles of muscle fascicles
What is a muscle fascicle?
Bundles of muscles fibers
What is a muscle fiber?
Skeletal muscle cell
Describe a skeletal muscle fiber.
Many nuclei, large multinucleate cells.
Describe the development of muscle fibers.
Complete development after birth (very little mitosis after birth), increased muscle size after birth through muscle fiber hypertrophy
What causes hypertrophy of muscle fibers?
Increased fiber protein in the form of myofibrils
What is a sarcolemma?
Muscle fiber plasma membrane
What is sarcoplasm?
Muscle fiber cytoplasm
What is the sarcoplasmic reticulum?
Muscle fiber endoplasmic reticulum that surrounds myofibrils. Contains calcium.
What is a myofibril?
Long strands of complex, contractile proteins within muscle fibers (1000s per muscle fiber) surrounded by SR.
What are transverse tubules (T tubules)?
Tubes that form from the sarcolemma and transverse, at right angles, into the interior of the muscle fiber. Send action potentials into the interior of the fiber.
What do myofibrils consist of?
Overlapping thick and thin myofilaments
What are thick myofilaments?
Groups of myosin protein
What are thin myofilaments?
Strands of actin protein
What is the M line?
Point where myosin proteins attach to each other
What is the Z line?
Point where actin proteins attach to each other
What are I bands?
Bands created by thin myofilaments
What are A bands?
Bands created by overlap of thin and thick myofilaments
What is the H zone?
Area within A band where thin and thick filaments don’t overlap
What is a sarcomere?
Z line to Z line in a myofibril (skeletal muscle contractile unit)
What are motor neurons?
Neurons that control skeletal muscle contraction
How many neurons control a muscle?
As many as 100-1000
How many muscle fibers does one neuron terminal control?
1
What is a motor unit?
The neuron and all the muscle fibers it controls
What is the neuromuscular junction?
Where the neuron terminal contacts the fiber and releases a neurotransmitter
What are the steps of muscle contraction initiation at the neuromuscular junction?
- An action potential in a motor neuron is propagated to the axon terminal
- This local action potential triggers the opening of a voltage-gated Ca+ channel
- Ca+ triggers the release of acetylcholine by exocytosis from the vesicles
- ACh diffuses across the space separating nerve and muscle cells and binds with receptor-channels
- The binding brings about the opening of nonspecific cation channels, leading to large movement of Na+
- The result is an end-plate potential. Local current flow occurs between the depolarized end plate and adjacent membrane
- The local current flow opens voltage-gated Na+ channels in the adjacent membrane
- The resultant Na+ entry reduces the potential to threshold, initiating an action potential.
- ACh is destroyed by acetylcholinesterase, terminating the muscle cell’s response
What causes action potential in muscle fiber?
Firing of a motor neuron and release of neurotransmitter at neuromuscular junction
What does ACh bind to?
Cholinergic receptorss in muscle fiber sarcolemma at neuromuscular junction
What do cholinergic receptors open?
Sodium channels
What is the neuron neurotransmitter?
Acetylcholine (ACh)
What are the types of cholinergic receptors?
Nicotinic and muscarinic
What happens when voltage gated Na+ channels open at the neuromuscular junction?
An action potential is conducted along muscle fiber membrane and T-tubules
What are T-tubules linked to?
SR
What happens when action potential reaches the SR?
Voltage gated Ca+ channels in the SR open
What happens when calcium enters the sarcoplasm?
It surrounds thin and thick myofilaments. Myofilaments interact and muscle contraction occurs
What happens when Ca+ is in the SR?
The troponin-tropomyosin complex blocks actin binding sites on thin myofilament and myosin cannot bind actin
How does calcium modify the troponin-tropomyosin complex?
It exposes binding sites on actin thin myofilaments. The thick myofilament-myosin cross-bridge can now attach.
What is a power stroke?
When ATP is used by myosin cross-bridge to pull the thin myofilament and detach
What is cross-bridge cycling?
When the power stroke process is repeated in the presence of Ca+ and ATP
What are the steps of cross-bridge cycling?
- Calcium from SR removes troponin-tropomyosin complex from actin, uncovering myosin binding sites on the actin strand.
- ATP-charged myosin cross-bridge binds to actin
- Myosin cross-bridge bends toward the center sarcomere, pulling actin past myosin.
- The myosin cross-bridge remains bound to actin until a new ATP molecule binds the myosin cross-bridge, detaching it from actin and causing it to recharge and reattach.
What does cross-bridge cycling cause?
Decreasing of the length of sarcomere, causing muscle contraction.
How does skeletal muscle relaxation occur?
Motor neurons stop firing, acetylcholinesterase enzyme degrades ACh in neuromuscular junction, SR calcium carrier proteins pump calcium back into SR, thin and thick myofilaments detach.
What are non-depolarizing agents?
ACh antagonists, bind ACh nicotinic receptors at neuromuscular junction and block sodium entry
What are depolarizing agents?
ACh agonists, bind ACh nicotinic receptors and persistently depolarizes muscle fiber. acetylcholinesterase has no function to remove signal. Saturates receptor and resting membrane potential can’t be reestablished. Loss of sensation over time.
What is tetrodotoxin?
ACh antagonist
What are examples of ACh antagonists?
Botulinum neurotoxin, curare, and tetrodotoxin
What are acetylcholinesterase antagonists and what do they do?
Block acetylcholinesterase activity and maintains muscle in contracted state. Diaphragm remains contracted, leading to suffocation.
What are some examples of acetylcholinesterase antagonists?
Malathion, parathion, and diazinon (insecticide compounds), similar to nerve gas.
What is the importance of ATP in muscle?
It is needed for the power stroke and to release thick from thin myofilaments, SR Ca+ carriers use ATP to pump Ca+ back into SR, sodium-potassium ATPase pump uses ATP to transport sodium out of muscle fiber and reestablishes the cell”s resting membrane potential.
What is creatine phosphate (CP)?
A molecule used by muscle fiber to phosphorylate ADP and replenish ATP
What is glycolysis?
A way of making ATP. Less oxygen is needed and it is a quick process, but fewer ATP is produced.
What is the citric acid cycle and oxidative phosphorylation?
A way of making ATP. Requires more oxygen and is a slower process, but it produces significantly more ATP.
What is oxygen provided by?
Increased respiration and heart rate, increase in skeletal muscle arterial diameter, presence of myoglobin in muscle, and reduced affinity of red blood cell hemoglobin for oxygen in muscle.
What is glucose provided by?
Diet, stored as muscle as glycogen
What is muscle fatigue?
A decrease in muscle contraction capacity and decreases muscle activity.
What does high intensity exercise do?
Reduce CP, ATP, oxygen, and glucose
What molecule can accumulate in muscle fiber?
Lactic acid
What causes lactic acid accumulation and what does lactic acid accumulation cause (muscle)?
Lactic acid is a biproduct of glycolysis. Reduces muscle and blood pH (acidosis) and results in muscle pain.
What are the characteristics of type 2 muscle?
White fibers, anaerobic, fewer blood vessels, less myoglobin, fewer mitochondria, faster to contract, less endurance
What are the characteristics of type 1 muscle?
red fibers, aerobic, more blood vessels, more myoglobin, more mitochondria, slower to contract, more endurance
What is smooth muscle?
Involuntary and non-striated muscle
What are the functions of smooth muscle?
Accommodation (provides room for content within organs), transports food through digestive system, regulated blood flow through blood vessels, regulates air flow through respiratory tract, transports eggs, sperm, and fetus through reproductive tract
What controls smooth muscle contraction?
The nervous system, hormones, and paracrine ligands
What is single unit smooth muscle?
99% of smooth muscle in the animal body, found surrounding organs and blood vessels, muscle that contracts as a unit
How does single unit smooth muscle contract as a unit?
It uses gap junctions to share ions and transmit action potentials
What are slow waves?
Fluctuations in membrane potential
What is multi-unit smooth muscle?
1% of smooth muscle. Found surrounding large blood vessels, airways in lungs, iris in eye, and skin hair follicles. Each smooth muscle is controlled by an individual neuron. Independent smooth muscle.
What function does multi-unit smooth muscle provide?
Finer control over contraction and constriction
What are the steps/mechanism of smooth muscle contraction?
- During action potential Ca+ enters cell through voltage-gated channels in cell membrane or endoplasmic reticulum.
- Ca+ binds calmodulin protein.
- Ca+/calmodulin complex activates myosin light chain kinase (MLCK)
- MLCK phosphorylates myosin light chain and activates myosin.
- Myosin cross-bridge interacts with actin and cross-bridge cycling begins.
What is cardiac muscle?
Involuntary and striated muscle
What are myocardiocytes?
Heart specific myocytes (muscle cell)
What do pacemaker cells do?
Generate repetitive spontaneous action potentials that spread throughout myocardiocyte gap junctions
What is a visible characteristic specific to cardiac muscle?
Intercalated discs
What does the nervous system do?
Helps the animal sense environment, coordinates limb movement and organ function, maintains animal consciousness, responsible for animal behavior and learning, and controls some reproductive processes.
What are neurons?
Specialized cells that transmit action potentials over long distances throughout the body.
What do neurons secrete?
Neurotransmitters and neuroendocrine hormones
What are glial cells?
Cells that support neuron function
What are examples of glial cells?
Astrocytes, oligodendrocytes, and schwann cells
What are dendrites?
The input zone of a neuron that receives incoming signals from other neurons
What is the cell body of a neuron ?
The trigger zone. Initiates action potentials.
What is the axon of a neuron?
Conducting zone. Conducts Action potentials in non-diminishing fashion over long distances
What are axon terminals?
Output zone. Releases neurotransmitters that influence other cells
What is a myelin sheath?
A sheathe surrounding the axon of a neuron, created by glial cells.
What are the steps of neurotransmitter release at synapse.
- Action potential reaches axon terminal of presynaptic neuron
- Ca+ enters synaptic knob
- Neurotransmitter is released by exocytosis into synaptic cleft
- Neurotransmitter binds to receptors that are an integral part of chemically gated channels on subsynaptic membrane of postsynaptic neuron.
- Binding of neurotransmitter to receptor opens that specific channel
What are common neurotransmitters?
Acetylcholine, norepinephrine, gamma-aminobutyric acid (GABA), glutamate, and dopamine
How do excitatory neurotransmitters effect action potentials?
Increases them by opening voltage-gated Na+ channels
How do inhibitory neurotransmitters effect action potentials?
It inhibits them by opening voltage-gated potassium channels
What happens if an excitatory presynaptic input (Ex1) is stimulated a second time after the first EPSP in the postsynaptic cell has died off?
A second EPSP of the same magnitude will occur
What happens if Ex1 is stimulated a second time before the first EPSP has died off?
The second EPSP will add onto the first EPSP, resulting in temporal summation, which may bring the postsynaptic cell to threshold.
What is spatial summation?
When the postsynaptic cell is brought to threshold by the simultaneous activation of two or more excitatory presynaptic inputs.
What are the steps of ending the neural signal?
- Neuron stops releasing neurotransmitter
- Enzyme at synapse degrades neurotransmitter
- Neurotransmitter is reabsorbed by neuron terminal
- Neurotransmitter diffuses away from synapse into extracellular environment
What is the central nervous system (CNS)?
The neurons in the brain, brain stem, and spinal chord.
What is the peripheral nervous system (PNS)?
The neurons going to and coming from the CNS
What are afferent neurons?
Sensory neurons that send info to CNS
What are efferent neurons?
Neurons from the CNS that influence an “effector” (target) tissue, such as a muscle or a gland.
What are the afferent neurons that sense the environment?
Skin, muscles, tendons, eyes, ears, nose, tongue, blood vessels, and organs
What are the efferent neurons that send information to effector or target tissues?
Skeletal muscle, cardiac muscle, smooth muscle, and glands
What are mechanoreceptors?
Receptors that sense pressure, shrinkage, or stretch
What are chemoreceptors?
Receptors that sense chemicals
What are thermoreceptors?
Receptors that sense changes in temperature
What are photoreceptors?
Receptors that sense photons or light waves
What is a pacinian corpuscle?
A mechanoreceptor in skin that is sensitive to pressure
What are baroreceptors?
Mechanoreceptors in the heart and large arteries that are sensitive to stretch and blood pressure
What are osmoreceptors?
Mechanoreceptors Found in the brain that are sensitive to shrinkage and body dehydration
What are nociceptors or pain receptors?
Receptors that sense tissue damage and include chemoreceptors, mechanoreceptors, and thermoreceptors
What are proprioceptors?
Sensory receptors that provide a sense of awareness of body position, movement, and acceleration (proprioception)
What does proprioception involve?
Mechanoreceptors found in joints, muscles, and tendons; balance and vision sensory information to coordinate animal body movement
What organs sense muscle length, stretch, or tension?
Muscle spindles and golgi tendon organs
What are muscle spindles?
Special muscle fibers within a muscle that activate afferent neurons
What are golgi tendon organs?
Afferent neurons directly within tendons
What is the spinal chord?
The continuation of nervous tissue that extends from brain stem through vertebral foramen to caudal vertebrae.
What does the spinal cord consist of?
Myelinated neuron axons and neuron cell bodies
What is the integration center?
The place that gathers information from PNS and provides a communication link to CNS
What is dorsal nerve root?
Where afferent neurons enter the spinal cord
What is a ventral nerve root?
Where efferent neurons exit the spinal cord
What is a spinal nerve?
The joining of dorsal and ventral nerves. One pair per vertebrae exiting left and right intervertebral foramen
What is the somatic nervous system (SNS)?
Efferent neurons providing voluntary control of skeletal muscle
What is the autonomic nervous system (ANS)?
Efferent neurons providing involuntary control of glands, cardiac muscle, smooth muscle around organs, airways, and blood vessels
What are the components of the reflex arc?
- Activation of sensory receptor neuron
- Afferent neuron/pathway
- Interneuron/integrating center
- Efferent neuron/pathway
- Activation of effector tissue (skeletal muscle)
Describe the PNS.
Typically associated with reduced effector activity, sometimes called the “breaks” or “rest and digest,” neurons extend from cranial and sacral regions to effector tissues
Describe the SNS.
Typically associated with increased effector activity, sometimes called “the gas,” associated with fight or flight, takes precedence over PNS, neurons extend from thoracic and lumbar regions to effector tissues.
What do the SNS and PNS balance?
Heart rate, respiration, and digestion.
What part of the brain is the a major control center for the SNS and PNS?
The brain stem medulla oblongata
What is a ganglion?
A relay center for neurons in the PNS
What chemical do pre-ganglionic neurons release in the SNS?
ACh
What chemical do post-ganglionic neurons release in the SNS?
Norepinephrine
What receptors are on post-ganglionic neurons of the SNS?
Cholinergic nicotinic receptors
What receptors are on effector tissue of the SNS?
Adrenergic alpha and beta receptors
What are adrenergic alpha and beta receptors also activated by?
Epinephrine produced by the adrenal gland
What chemical do pre- and post- ganglionic neurons release in the PNS?
ACh
What receptors are on post-ganglionic neurons in the PNS?
Cholinergic nicotinic receptors
What receptors are on effector tissue in the PNS?
Cholinergic muscarinic receptors
What does the brain stem medulla oblongata do?
It controls most autonomic neurons to the cardiovascular, respiratory, and digestive system.
What is cranial nerve X (CNX)?
The vagus nerve. A major route for autonomic neurons to the cardiovascular, respiratory, and digestive system?
What is another region of the brain (besides the brainstem medulla oblongata) that controls the ANS? Does this region control other portions of the nervous system?
The hypothalamus, controls the somatic nervous system and skeletal muscle
What is the splanchnic nerve?
Sympathetic pre-ganglionic neurons that directly enter the adrenal gland medulla and release ACh onto chromaffin cells.
What happens to the nervous system during stress?
Firing of the splanchnic nerve and release of ACH causes chromaffin cells to release epinephrine into the blood
Why is epinephrine important for fight or flight?
E has a strong affinity for adrenergic receptors on cardiac muscle and the smooth muscle around organs, airways, and blood vessels and triggers rapid changes in animal physiology.
What are the outputs of the adrenal gland medulla?
Glucocorticoids, epinephrine, and norepinephrine
What are the effects of epinephrine on animal physiology?
Increases in heart rate, respiration, blood pressure, blood glucose, and pupil dilation. Decreases in digestive activities and reproductive activities.
What is the enteric/intrinsic nervous system?
Nerve network in walls of the digestive tract, liver, and pancreas.
What is the enteric/intrinsic nervous system controlled by?
The ANS, but it can also act independently to control digestive activities.
What are the two nerve layers of the enteric/intrinsic nervous system?
Meissner’s/submucosal plexus, Auerbach’s/myenteric plexus
What doe the neurons in the enteric/intrinsic nervous system sense?
Stretch, food molecules, paracrine ligands, and hormones
What does the enteric/intrinsic nervous system have local control over?
Digestive system smooth muscle, blood flow, and digestive system secretion
