Exam 3 Worksheet Answers Flashcards
Compare the structure of fibrous, cartilage, and synovial joints, and give an example of each. How does the structure affect the mobility of the joint?
fibrous joints are held together by connective tissue proper (predominantly fibroblasts, collagen, and little ground substance); suture joints of the skull are an example. Cartilaginous joints are held together by cartilage, typically hyaline cartilage or fibrocartilage. The pubic symphysis, holding the two hip bones together anteriorly, is an example of a (fibro)cartilaginous joint. In both fibrous and cartilaginous joints, the connecting material directly attaches to the ends of the bones, preventing them from actually contacting each other directly.
Synovial joints are unique in that the bones are held together by a joint capsule made of dense connective tissue that leaves a space between the two bones; synovial fluid fills the space in the capsule, and lubricates the surfaces where the bones contact one another. This arrangement allows more freedom of movement between the bones while protecting the bony surfaces from wear. All movable joints are synovial joints.
What is the role of tendons and ligaments at joints?
Ligaments are strong bands of dense regular connective tissue holding two bones together at a synovial joint; they keep the bones from shifting.
Tendons are also made of dense regular connective tissue, and attach muscle to bone.
What role does fibrocartilage play as an added feature of some synovial joints?
Fibrocartilage is used as a stabilizing feature at a select few synovial joints (most synovial joints do not have fibrocartilage).
One use of fibrocartilage at ball and socket joints (hip, shoulder). Another is the meniscus cartilages of the knee.
name the plane in which the movement occurs: Flexion-Extension
sagittal
name the plane in which the movement occurs: Abduction-Adduction
coronal (frontal)
name the plane in which the movement occurs: Rotation
transverse
name the plane in which the movement occurs: Dorsiflexion-Plantarflexion
sagittal
A sac of synovial fluid that provides padding between a bone and another tissue is called a
bursa
At the knee joint, synovial fluid is produced by
Cells in the membrane lining the joint capsule
Standing on the toes, as a ballet dancer might do, is as example of which movement?
plantarflexion
Visualize a cross-section through the forearm. What layers would be apparent? What tissues comprise the layers? What holds the layers together?
The outermost layer visible is the skin, which itself has outer and inner layers. The outermost portion of the skin is a stratified squamous epithelium called epidermis; the inner layer of skin is a connective tissue proper layer called the dermis. Deep to the skin is a variable amount of fat, or adipose, tissue. Deep to that are skeletal muscles arranged around the radius and ulna. Dense connective tissue called deep fascia surrounds the muscles and connects on lateral and medial sides to the bones, separating the muscles into anterior and posterior compartments of the forearm. Anterior muscles flex the wrist and fingers; posterior muscles extend the wrist and fingers.
Connective tissue holds bones together, holds muscles to bones, groups muscles into compartments, and attaches skin to muscle – in other words, connective tissue proper connects all the other tissues together.
Compare Dense Regular Connective Tissue with Adipose Tissue. Which one would provide a better environment for nerves and muscles to travel through?
Dense regular connective tissue is a type of connective tissue proper that contains fibroblasts, large bundles of collagen fibers oriented parallel to one another, and very little gel-like ground substance.
Adipose tissue is also a type of connective tissue proper, but contains large numbers of adipose (fat) cells, small numbers of fibroblasts, little collagen and ample gel-like ground substance. Because collagen is resistant to deformation, dense regular connective tissue is very strong and relatively inflexible. Adipose tissue is much more malleable, and expands easily to accommodate nerves and blood vessels growing through the area. In addition, adipose tissue can act as padding around the nerves and vessels, protecting them from injury.
How do muscle cells attach to bone?
Muscle cells do not attach directly to bones. Muscle cells are surrounded by collagen; single cells are surrounded by endomysium, muscle fascicles by perimysium, and the entire muscle by epimysium. These are all names for the collagen-rich connective tissue encasing muscle. As muscle cells contract, they pull on the connective tissues around them. Endo-, peri- and epimysium layers merge to form the tendons at each end of the muscle; ultimately, as muscles contract they pull on the tendons.
Tendons attach to the connective tissue wrapping around a bone, called the periosteum. Collagen fibers of the tendons merge with collagen fibers of the periosteum, allowing a firm attachment to the bone. Thus, when a muscle attaches to a bone, it is the connective tissue around the muscle attaching to the connective tissue around the bone.
What is meant by the term “compartment” when referring to the muscular system?
A muscle compartment is a group of skeletal muscles surrounded by a continuous layer of dense connective tissue. This deep fascia is separate from the epimysium which surrounds each individual muscle – rather, it encloses an entire group of muscles, as well as nerves and vessels which travel between the individual muscles. Muscles in a compartment typically share the same action or actions, and are all supplied by the nerve and vessels in the compartment. Trouble in the compartment (inflammation, infection) typically affects all the contents of the compartment.
Why is nerve compression a problem?
Nerves are structures in the peripheral nervous system carrying axons to and from target tissues like skin and skeletal muscle. Nerves contain both sensory axons, collecting information from the target and sending it to the CNS, and motor axons, carrying commands from the CNS out to the peripheral targets. Compressing a nerve will compress some or all of the axons in the nerve. Compressing motor axons interferes with the instructions from the CNS to the target. Compressing sensory axons interferes with collecting sensations from the target, and typically also stimulates axons conveying pain from the target, leading to the sensation of pain.
which type of cell produces collagen fibers
osteocytes of compact bone
deep fascia is an example of which type of tissue
dense connective tissue
neuron
A neuron is a single electrical cell of the nervous system; it has a cell body, variable numbers of dendrites, an axon, and axon terminals
nerve
A nerve is a collection of many (dozens to many thousands) of axons, wrapped together with connective tissues (endoneurium around single myelinated axons, perineurium around fascicles, and epineurium surrounding the entire nerve), in the peripheral nervous system. Note that in the peripheral nervous system, the myelin is produced by Schwann cells.
fiber bundle
A fiber bundle is the term used to describe a collection of axons traveling together within the central nervous system. Axons are myelinated by oligodendrocytes in the CNS. There is no connective tissue with in the CNS, so there is no collagen wrapping around individual axons or around groups of axons. Axons simply travel adjacent to neighboring axons in the white matter, but there is no tissue in the CNS that can separate groups of axons from other groups
are nerves and fiber bundles similar in structure?
Nerves and fiber bundles as similar structures, in that they are both names given for large numbers of axons traveling together to a target. In the PNS, the axons are supported by connective tissue to form nerves. In the CNS, where there is no connective tissue, axons travel together in bundles without any obvious separation between groups, and are referred to as fiber bundles.
Describe the folding of the neural plate to form neural tube and neural crest
In the third week of human development, the embryo is a long, flat structure comprised of three cell layers. The nervous system forms from the most posterior (dorsal) of these three layers, the ectoderm. The central portion of this cell sheet undergoes rapid cell division, forming a longitudinal groove down the center of the sheet; this is called the neural groove. As the groove deepens, cells at the surface of the groove meet in the midline, closing the groove into a tube-like structure called the neural tube. This structure sinks under the surface and
forms the central nervous system, which will eventually become the brain and spinal cord. At the edges of the neural groove, called the crest region, another population of cells develops called the neural crest. These cell groups also sink under the surface, on either side of the neural tube; once these cells migrate away they will form all the parts of the peripheral nervous system.
At the surface, once neural crest and neural tube structures have sunk anteriorly, the remaining ectoderm grows back over the entire dorsal surface, to enclose the entire neural tube and neural crest under the skin.
List the major divisions of the adult CNS
The major divisions of the CNS, from rostral to caudal, are the cerebrum, diencephalon, brainstem (with three parts: midbrain, pons and medulla), and spinal cord; the cerebellum develops an outgrowth of the pons but is generally not considered a compartment of the brainstem.
Compare the composition of gray matter vs white matter: what cells or cell parts are located in each?
Gray and white are the two colors one sees when looking at sections through the CNS. White matter is white because myelin is white in color; thus, white matter represents areas where there are large numbers of myelinated axons traveling together. Gray matter is darker in color because of a relative lack of myelin, not because there are zero myelinated axons in the area. Gray matter contains neural tissue that lacks myelin – this includes cell bodies and dendrites, and axon terminals, and the support cells called astrocytes. Gray matter, then, represents areas where neurons are receiving information from other cells and processing that information. White matter represents the highways where cell bodies are transmitting information down their axons toward other areas of gray matter.
nucleus in the CNS
The word nucleus has several meanings in biology. Each cell has a nucleus, home of its DNA and the metabolic center of the cell. But when we think about the CNS, a nucleus is a term used to refer to a particular clump of gray matter. It represents an area where a large number of neuronal cell bodies are clustered together, and are receiving and processing information. Thus, each nucleus in the CNS is an area of gray matter with a particular function or functions, processing a particular type of information that makes it unique from other nuclear groups (other clumps of gray matter)
ganglion in the PNS
In the peripheral nervous system, the word nucleus is replaced with the term ganglion. A ganglion is a collection of neuronal cell bodies; all of those cells have a similar function. But ganglia in the PNS are always wrapped by connective tissue, just as axons of peripheral nerves are wrapped by connective tissue.
Distinguish between sensory neurons and motor neurons
Sensory neurons collect information from a structure in the periphery (skin, skeletal muscle) and carry that information into the CNS. The axons of those sensory neurons will end at synapses onto CNS neurons. Almost all sensory neurons are pseudounipolar in shape; their cell bodies are in a ganglion in the PNS, and their axon travels through a peripheral nerve until it enters the CNS.
Motor neurons carry information away from the CNS, toward a structure in the periphery (skin, skeletal muscle). Cell bodies of most motor neurons are in the CNS, and their axons travel out through a peripheral nerve to their target.
What is meant by the term mixed nerve?
A mixed nerve is a peripheral nerve that contains both sensory axons and motor axons (or, put another way, contains axons of sensory neurons and axons of motor neurons). To identify any individual axon as sensory or motor, you would need to know where its cell body resides or which direction action potentials flow down its axons (toward the CNS for sensory axons, away from the CNS for motor axons).
What distinguishes motor nerves from cutaneous nerves and autonomic nerves?
Motor nerves are branches of peripheral nerves that travel to skeletal muscle; sensory axons in the motor nerve collect feedback from the muscle, and motor axons in the motor nerve carry commands to the skeletal muscle telling it to contract. Thus, a motor nerve is a mixed nerve carrying information to and from a skeletal muscle. Cutaneous and autonomic nerves are also branches of peripheral nerves, and are also mixed nerves; they are distinguished by their targets. Cutaneous nerves connect to skin, while autonomic (splanchnic) nerves connect to organs.
Compare convergence and divergence of information in a neural circuit.
Neural circuits are neurons connected in series (one neuron connects to a target, which relays information to a different cell, who in turn relays information to another. Motor pathways are characterized by converging circuits: multiple pathways all feed information toward a single motor neuron, which controls a motor unit in a skeletal muscle.
Sensory pathways are characterized by divergence of information: one sensory neuron relays its information to several target cells, each of which has its own unique pathway. Thus, one piece of sensory information (such as pain from stepping on a tack) can end up in multiple places in the CNS, each formulating its own response to the stimulus.
what cerebral lobe is the Broca’s area found
frontal lobe
what cerebral lobe is the frontal eye field found
frontal lobe
what cerebral lobe is the limbic lobe found
frontal lobe and temporal lobe
what cerebral lobe is the prefrontal cortex found
frontal lobe
what cerebral lobe is the premotor cortex found
frontal lobe
what cerebral lobe is the primary auditory cortex found
temporal lobe
what cerebral lobe is the primary motor cortex found
frontal lobe
what cerebral lobe is the primary somatosensory cortex found
parietal lobe
what cerebral lobe is the primary visual cortex found
occipital lobe
what cerebral lobe is the wernicke’s area found
parietal lobe
what cortical region is responsible for fine motor control
primary motor cortex
what cortical region is responsible for limbic functions (personality)
prefrontal cortex
what cortical region is responsible for motor planning
premotor cortex
what cortical region is responsible for detecting fine sensory information
primary somatosensory cortex
what cortical region damage results in blindness
primary visual cortex
what cortical region damage results in fluent (receptive, sensory) aphasia
wenicke’s area
what cortical region damage results in deviation of eye to side of injury
frontal eye field
what cortical region damage results in syndrome of hemineglect
somatosensory association cortex
what cortical region damage results in non-fluent (expressive, motor) aphasia
broca’s area
anomia
can’t name
apraxia
can’t execute a motor activity based on verbal command
aphasia
language problem
motor/expressive aphasia
broca’s aphasia, can’t talk
sensory/receptive aphasia
wernicke’s aphasia, can’t understand
Describe what is meant by “hemispheric lateralization” and name two functions lateralized to the left
and right hemisphere.
Hemispheric lateralization describes the preferential localization of certain functions to either the left or right hemisphere. Language is lateralized to the left hemisphere even in most left-handed people. Mathematical ability and word comprehension are primarily left hemisphere functions, while musical ability, producing and understanding speech emotions, shape and face recognition are primarily right hemisphere functions.
Describe what is meant by a “topographic map” and name 4 cerebral functions that are mapped
The brain needs to respond to environmental cues appropriately (e.g., if your hand is on a hot stove
you don’t want to respond by lifting your leg). The two best-characterized topographic maps are the sensory and motor homunculus that maps body sensations and muscle groups for motor actions. Two other important maps are the tonotopic map of sound frequency/pitch in the primary auditory cortex and the visuotopic map of your visual space in the primary visual cortex.
The primary auditory cortex is located in the
temporal lobe
A shallow groove on the surface of the cerebral cortex is called a
sulcus
Broca’s area ________.
is considered a motor speech area
what brainstem location is the cerebral peduncle found
midbrain
what brainstem location is the inferior colliculus found
midbrain
what brainstem location is the nucleus cuneatus found
medulla oblongata
what brainstem location is the nucleus gracilis found
medulla oblongata
what brainstem location is the olivary nucleus found
medulla oblongata
what brainstem location is the pyramids found
medulla oblongata
what brainstem location is the red nucleus found
midbrain
what brainstem location is the reticular activating system found
midbrain
what brainstem location is the substantial nigra found
midbrain
what brainstem location is the superior colliculus found
midbrain
what brainstem structure’s function is: brainstem region vital to life (heartbeat, breathing)
medulla oblongata
what brainstem structure’s function is: midbrain nuclei involved in visual tracking of objects
superior colliculus
what brainstem structure’s function is: medulla nucleus that receives sensory info from body (leg)
nucleus gracilis
what brainstem structure’s function is: medulla axon bundles that carry descending motor info
pyramids
what brainstem structure’s function is: midbrain motor nucleus that controls arm flexion
red nucleus
what brainstem structure’s function is: midbrain structure responsible for maintaining consciousness
reticular activating system
what brainstem structure’s function is: midbrain axon bundles that carry descending motor info
cerebral peduncles
what brainstem structure’s function is: medulla nucleus involved in motor learning
olivary nucleus
what brainstem structure’s function is: brainstem region receiving most face sensory info
pons
what brainstem structure’s function is: midbrain nuclei involved in auditory localization
inferior colliculus
what brainstem structure’s function is: large axon bundles connecting cerebellum to brainstem
cerebellar peduncles
what brainstem structure’s function is: midbrain nucleus provides majority of dopamine to cerebrum
substantia nigra
what brainstem structure’s function is: medulla nucleus that receives sensory info from body (arm)
nucleus cuneatus
what brainstem structure’s function is: brainstem region involved in maintaining consciousness
midbrain
