A&P Test Review
19) Choose the correct sequence of events along an axon
1. a threshold stimulus opens Na+ channels and the ions diffuse in, depolarizing the cell membrane 2. K+ channels open, K+ exits, and the cell membrane repolarizes, generating an action potential that inhibits adjacent cell membrane, forming the nerve impulse
14) Explain how a membrane becomes polarized
A cell, in its normal state, has a negatively charged interior with respect to the exterior. This is accomplished by transport mechanism channels that let potassium ions move easily in and out, and keep sodium and calcium ions under tight control. Thus, A cell membrane is usually polarized as a result of unequal ion distribution.
50) vomiting is controlled by:
B. the medulla oblongata
15) describe how ions associated with nerve cell membranes are distributed
Because of the active transport of sodium and potassium ions, neuronal and other cells of the body have a greater concentration of sodium ions (Na+) outside and a greater concentration of potassium ions (K+) inside.The cytoplasm of these cells has many large, negatively charged particles, including phosphate ions (PO4-3), sulfate ions (SO4-2), and proteins, that cannot diffuse across the cell membranes. hence, the inside of cell membrane is negatively charged and outside is positively charged.
36) Name the 4 major parts of the brain and describe their general functions
Cerebrum The cerebrum constitutes the largest part of the human brain. It is also known as the cortex and is responsible for performing a great number of important brain functions, including action and thought processing. The cerebrum is further subdivided into four different sections that have their own respective functions and are termed as lobes. The names of these lobes are; frontal lobe, occipital lobe, parietal lobe and temporal lobe. Cerebellum The cerebellum is known as the little brain and resembles the cerebrum for it has a highly folded surface and distributed in 2 hemispheres. This part of the brain is responsible for performing functions like balance, posture and coordination of movement. Even though the cerebellum is smaller in size, it contains more neurons than the entire brain itself. The cerebellum is located at the back of the brain stem and on top of the pons. Limbic System The limbic system lies inside the cerebrum. It is also sometimes called the emotional brain because it takes charge of our emotional response. The thalamus, hypothalamus, amygdala and the hippocampus are the four different sections that make up the limbic system. Brain Stem When we talk about parts of the brain and their functions, brain stem should never be overlooked. The brain stem is located underneath the limbic system. This section of the brain is tasked with the duty of supervising important tasks such as blood pressure, breathing and heartbeat. Moreover, the brain stem organizes reflexes and coordinates the fine movement of the face and limbs. It is composed by midbrain, pons and medulla.
18) list the events that occur during an action potential
During an action potential, the neuron undergoes: 1. depolarization 2. opening of the axon 3. diffusion of sodium ions 4. opening of potassium channels 5. diffusion of potassium ions \ 6. repolarization 7. generation of impulse
3) explain the relationship between the CNS and the PNS
The CNS includes the brain and the spinal cord that serves as a command center of the body where the motor information came from, this motor information will go to the PNS that include the nerves to travel to areas of the body, the PNS sends sensory information to CNS vice-versa.
11) distinguish between ganglia and nuclei
The cell bodies of unipolar neurons are found in some of the specialized masses of nervous tissue called ganglia , which are located outside the brain and spinal cord (CNS). The cell bodies of some interneurons aggregate in specialized masses of nervous tissue called nuclei , which are located within the central nervous system.
1) The general function of neurons is to _____, whereas the general functions of neurologia are to __________.
The general function of neurons is to react to physical and chemical changes in their surroundings , whereas the general functions of neuroglia are to provide physical support, insulation, and nutrients for neurons
39) distinguish between a sulcus and a fissure
The sulcus pertains to the shallow ridges. The fissures pertains to the deep groves.
24) Match the neurotransmitter to description 1. biogenic amine 2. acetycholine 3. neuropeptide 4. GABA A. short chains of amino acids B. a modified amino acid C. an amino acid D. stimulates skeletal muscle contraction
biogenic amine- a modified amino acid acetycholine- stimulates skeletal muscle contraction neuropeptide- short chains of amino acids GABA- an amino acid
37) The area of the brain that contains centers controlling visceral activities is the ________
brainstem
7) the part of the Schwann cell that contributes to the myelin sheath is the ____________, and the part that contributes to the neurilemma is the _____________
cell membrane/(membranous portion) cytoplasm/ (nuclei)
38) The structure that connects the cerebral hemispheres is the ________
corpus callosum
2) Match the neuron to description 1. dendrite 2. axon 3. cell body A. a cell process that sends info B. one of usually several cell processes that receive info C. the rounded part of a neuron
dendrite- one of usually several cell processes that receive information axon- a cell process that sends information cell body- the rounded part of a neuron
49) list the functions of the 3 parts of the brainstem
functions of the midbrain include controlling arousal, alertness, and sleep-wake cycles by the structure that is called the reticular formation, dopamine production, which are also involved in the movement control and neural reward system; pain suppression, motor coordination, and visual and auditory processing Pons, along with medulla oblongata, is important for generating and regulating the respiratory rhythm; responsible for eye movement, sensory and motor innervation of the face, and maintaining balance, respectively The medulla oblongata contains cardiac, respiratory, and vasomotor centers which control the vital autonomic functions of the body: the heart rate, respiration, and the diameter of the blood vessels. (also maintaining balance, hearing, coughing, sneezing, swallowing, gag reflex)
46) the part of the diencephalon that regulates hunger, weight, water and electrolyte balance, sleep and wakefulness, temp, arterial blood pressure, heart rate, production of substances that stimulate the pituitary gland, and movement and secretion in areas of the digestive tract is the _________
hypothalamus
48) the parts of the brainstem are the _______, __________, and ___________.
midbrain, pons, and medulla oblongata
52) describe the functions of the cerebellum
reflex center for processing sensory information for correcting body positioning and coordinating muscle movements. It keeps maintain posture, muscle tone, movement, and equilibrium.
47) define "limbic system" and explain its functions
The limbic system is a structure found in the general area of the diencephalon. The limbic system is responsible for controlling emotional responses and expressions. It recognizes emotional stimulus and regulates on how a person acts on the said stimulus. It also aids in survival as it functions as a guide on how to act on physical and psychological conditions that may prove as a threat.
40) relate the lobes of the cerebral hemisphere to the skull bones
The lobes of the cerebral hemisphere are named after the bones of the skull on which they underlie. Frontal, parietal, temporal, and occipital.
41) Locate the sensory, association, and motor areas of the cerebral cortex, and describe the general functions of each.
The sensory area interprets the impulses and information from the sensory receptors. These can be found on several parts of the lobes. Association areas analyze and interpret sensory stimuli and play a role in moderating memory, reasoning, emotions, and judgment. These are located on the anterior part of the frontal lobe, lateral portions of the parietal, occipital, and temporal lobes and are responsible for connecting the sensory and motor areas, making them function in between. Motor area is found on the frontal lobe and is made up of pyramidal cells or upper motor neurons.
5) Match types of neuroglia to functions 1. ependymal cells 2. oligodendrocytes 3. astrocytes 4. Schwann cells 5. Microglial cells A. Form a myelin sheath around peripheral nerves B. Phagocytize cellular debris and bacteria C. Line inner parts of ventricals and spinal cord D. Form scar tissue and regulate ion and nutrient concentrations in the CNS E. Form a myelin sheath around neurons in CNS
(1) ependymal cells-(C.) line inner parts of ventricles andspinal cord (2) oligodendrocytes-(E.)form a myelin sheath around neurons in the CNS (3) astrocytes-(D.) form scar tissue and regulate ion andnutrient concentrations in the CNS (4) Schwann cells-(A.) form a myelin sheath around peripheral nerves (5) microglial cells-(B.) phagocytize cellular debris and bacteria
4) List the general functions of the nervous system
1. Sensory - detect internal and external changes 2. Integrative - collect sensory information and make decisions that motor functions carry out 3. Motor - stimulate effectors to respond
42) define "hemisphere dominance"
Hemisphere dominance is the occurrence wherein the left side or the right side is more dominant.
16) Define resting potential
In a resting cell, more positive ions leave than enter, so the outside of the cell membrane develops a positive charge, while the inside develops a negative charge. Thus during resting potential A high concentration of sodium ions is outside a cell membrane, and a high concentration of potassium ions is inside.
8) distinguish between myelinated and unmyelinated axons
In unmyelinated axons, impulse conduction happens over its entire surface. A myelinated axon contains a high proportion of lipid which serves as an insulator.
9) distinguish among multipolar, bipolar, and unipolar neurons
Multipolar neurons have one axon and many other extensions from the cell body that serve as dendrites. Bipolar neurons have only two nerve fibers, one is the axon and one is the dendrite. They are from opposite sides of the cell body. Unipolar neurons have a single nerve fiber extending from the cell body. From there it branches in two directions; one branch extends into a peripheral body part and serves as a dendrite. The other extends into the CNS and acts like an axon.
6) COME BACK Describe 3 structures found in neurons that are also in other cell types, and describe 2 structures that are unique to neurons
Multipolar- many processes and lies within the brain or CNS Unipolar-single process, function as a single axon, two branches one in the PNS and one in the CNS Bipolar-have only two processes, one is an axon and the other is a dendrite; in the ears, eyes, nose, PNS Two structures unique to neurons: Axon and Dendrite
43) the function of the basal nuclei is to _________ OMIT
OMIT
45) Explain how cerebrospinal fluid is produced and how it functions OMIT
OMIT
10) distinguish among sensory neurons, interneurons, and motor neurons
Sensory (afferent) neurons sense changes inside or outside the body by means of receptor ends or nearby receptor cells. They send impulses to the CNS in response to these changes. Most of these neurons are unipolar, with some bipolar. Interneurons (association or internuncial neurons) are multipolar neurons found in the CNS. They link with other neurons and send impulses from one part of the CNS to another. Motor (efferent) neurons are multipolar, and send impulses from the CNS to muscles or glands. There are two types of motor neurons that control smooth or cardiac muscle. Accelerator neurons increase muscle activity, while inhibitory neurons decrease muscle activity.
44) locate the ventricles in the brain
Ventricles are defined as interconnected cavities in the cerebral hemisphere and brainstem that contain cerebrospinal fluid.
17) explain the relationship between threshold potential and action potential
When neurons are depolarized sufficiently, the membrane potential reaches a level called the threshold potential, which is approximately -55 millivolts. Achieving threshold potential triggers an action potential.
51) describe what happens to the body when the reticular formation receives sensory impulses, and what happens when it does not receive stimulation
responsible for the state of wakefulness of a person. It gets activated the sensory impulses and in turn, it activates the cerebral cortex. The cerebral cortex will be aware of the information and will process the sensory impulse and will be in a state of wakefulness or consciousness. vs An injury to the reticular formation or a decrease in activity will result to inactivation of the cerebral cortex and will be in a state of sleep or even in a comatose state.
