anatomy lab midterm Flashcards
1
Q
define homeostasis. why do we need it?
A
is the ability of the body to maintain a controlled
and stable internal environment by responding to internal and external stimuli. The majority
of body functions can only occur if conditions such as temperature, pH, and solute
concentrations in the body are maintained within specific physiological parameters.
2
Q
what are the two divisions of the nervous system?
A
The cental nervous system which is made of the brain and spinal cord and the peripheral nervous system which is made of cranial and spinal nerves, ganglia and sensory receptoprs
3
Q
what is a ganglion
A
a collection of neuronal bodies found in the voluntary and autonomic branches of the peripheral nervous system (PNS). Ganglia can be thought of as synaptic relay stations between neurons. The information enters the ganglia, excites the neuron in the ganglia and then exits.
4
Q
what are neurons / nerve cells?
A
. The neurons or nerve cells form the functional portion of the system.
Neurons are highly specialized for impulse conduction and are responsible for all the special
attributes associated with the nervous system, such as thinking, controlling muscle activity,
and regulating glands
5
Q
what are the 3 different classes of neurons
A
- Sensory (afferent) neurons: the neuron that conducts the impulse from the sensory
receptor to the central nervous system. - Interneuron (association neuron): integrates information from the sensory neurons
and passes the stimulus to motor neurons. - Motor (efferent) neurons: the neuron that conducts the impulse from the central
nervous system to an effector, usually a muscle or a gland.
6
Q
describe dendrites
A
dendrites = little trees. they are the thing surrounding cell body that look like alien arms. they are the receiving or input portion of a neuron. the plasma membrane has numerous receptor sites for bringing chemical messengers from other neurons called dendritic spines
7
Q
describe the cell body (also called soma)
A
contains a nucleus surrounded by cytoplasm that includes typical cellular organelles. also contain free ribosomes and prominent clusters of rough endoplasmic reticulum called nissl bodies
8
Q
what is an axon and axon hillock
A
an axon is a long, thin cylindrical projection that ofen joins to the cell body at a cone-shaped elevation called the axon hillock
9
Q
describe the axon collateral
A
along the length of an axon, side branches called axon collateral may branch off, typically at a right angle to the axon
10
Q
what are axon terminals
A
the axon and its collaterals end by dividing into many fine processes called axon terminals
11
Q
describe synaptic end bulbs/ varicositites
A
bulb-shaped structures. both synaptic end bulbs and varicosities contain many tiny membrane-enclosed sacs called synaptic vessels. these store neurotransmitters that excites of inhibits another neuron
12
Q
what are Schwann cells
A
these cells encircle the entire PNS axons. They form the myelin sheath around axons. it can only myelinate a single axon and can enclose as many as 20 or more unmyelinated axons. Participate into axon regeneration
13
Q
describe the myelin sheath
A
a multilayered lipid and protein covering around some axons that insulates them and increases the speed of nerve impulse conduction. such axons are said to be myelinated
14
Q
describe the nuerolemma
A
The outer nucleated cytoplasmic layer of the Schwann cell, which encloses the myelin sheath, is the neurolemma . A neurolemma is found only around axons in the PNS. When an axon is injured, the neurolemma aids regeneration by forming a regeneration tube that guides and stimulates regrowth of the axon
15
Q
what are myelin sheath gaps/ nodes of Rnavier
A
Gaps in the myelin sheath, called myelin sheath gaps, appear at intervals along the axon. Each Schwann cell wraps one axon segment between two myelin sheath gap
facilitate the rapid conduction of nerve impulses
16
Q
label axon
A
17
Q
what type of neuron is this. describe it
A
multipolar neurons have several dendrites and one axon and are the neuron type that
dominates the CNS.
18
Q
what is the structural classification of this neuron
A
- Bipolar neurons have one dendrite and one axon and are found in the retina of the eye,
inner ear, and the nasal epithelium
19
Q
what is the structural classification of this neuron
A
- Unipolar neurons have a fused axon and dendrite that emerge from the cell body as one
unit. The dendrites of these neurons form many of the other sensory receptors in the PNS
20
Q
recognize slides
A
21
Q
what is neuroglia / nueroglial cells
A
. Neuroglial cells
perform many different functions such as providing structural support for neurons, forming
myelin sheaths around axons, engulfing microorganisms and cell debris, and forming
cerebrospinal fluid. They also serve to prevent some substances from entering the central
nervous system.
22
Q
astrocytes: PNS or CNS Functions
A
largest and most numerous. two types, found in grey matter and white matter. MANY FUNCTIONS! support neurons, creates blood brain barrier, regulate the growth, migration, and interconnection among neurons. during embryotic development, maintain appropriate chemical environment. may play role in memory and learning
CNS
23
Q
oligodendrocytes: CNS or PNS; functions
A
CNS
responsible for forming and maintaining the myelin sheath around CNS axons
24
Q
microglia: CNS or PNS functions
A
act like phagocytes. remove cellular debris formed during normal development of the nervous system and phagocytize microbes and damaged nervous tissue
CNS
25
ependymal cells: CNS or PNS; functions
CNS
have microvilli and cilia. Functionally, ependymal cells produce, possibly monitor, and assist in the circulation of cerebrospinal fluid. They also form the blood–cerebrospinal fluid barrier,
26
Schwann cells: PNS or CNS; functions
PNS
form myelin sheath around axons like oligodendrocytes. A single oligodendrocyte myelinates several axons, but each myelinates a single axon Schwann cells participate in axon regeneration, which is more easily accomplished in the PNS than in the CNS
27
satellite cells: PNS or CNS; function
PNS
Besides providing structural support, satellite cells (SAT-i-līt) regulate the exchanges of materials between neuronal cell bodies and interstitial fluid
28
functions of neurons vs neuroglia
neurons: transmit nerve impulses, and they are the only type of human cells that can carry out this function.
neuroglia: neuroglia provide support for neurons and help them carry out the basic function of nervous tissues, which is to transmit nerve impulses.
29
describe the structure of the spinal cord
The spinal cord is protected by the bony vertebral column and extends from the medulla
oblongata in the brain stem to the L2 vertebrae (in adults)
30
white matter vs gray matter
In the spinal cord, bundles of
axons that make up the white matter carry sensory information to the brain and motor
information back to the peripheral nervous system. The centrally located gray matter of the
spinal cord contains cell bodies and axons of interneurons.
31
what is the function of the spinal cord
The function of the spinal cord is impulse propagation from the peripheral nervous system to
the brain and from the brain to the various effectors in the body. There is also integration of
some information from sensory to motor impulses.
32
describe the meninges and what they do
Surrounding the spinal cord are three layers of connective tissue called spinal meninges.
These layers of connective tissue protect and cushion the spinal cord in the vertebral column
and are continuous with the cranial meninges that enclose the brain.
33
describe the dura mater, arachnoid mater and subdural space
The superficial layer of the spinal meninges is called the dura mater. This layer is composed
of dense irregular connective tissue and is the toughest and most protective layer of the
meninges. The middle layer is called the arachnoid mater and is composed of collagen and
elastic fibers. Between the dura mater and arachnoid mater is the subdural space which is
filled with interstitial fluid.
34
describe the pia mater the epidural space and the subarachnoid space
The deepest layer of the meninges adheres to the spinal cord and is called the pia mater.
This layer contains many blood vessels that nourish the tissues of the underlying spinal cord.
The epidural space is the cavity between the bone of the vertebral column and the dura
mater, and is filled with fat and other connective tissues. The space between the arachnoid
and the pia mater is called the subarachnoid space and is filled with cerebrospinal fluid.
35
fill in the three meninges and 3 "spaces" from deep to superficial
pia mater, subarachnoid space, arachnoid mater, subdural space, dura mater, epidural space FACT CHECK
36
label the spinal cord
37
grey mater, anterior horn and posterior horn function
grey mater conatins clusters of nerual cell bodies called nuclei, the anteror gray horn provides nerve impulses (motor)
the posterior grey horn has sensory neurons as well as cell bodies (incoming sensory info)
38
white matter function
coantain funiculus, carries information up and down the spinal cord. connects regions that send and receive signals
39
function of the spinal nerves
connects the CNS to sensory receptors
40
function of the central canal
encompasses an internal system of cerebrospinal fluid
41
what are nerve roots? what is the difference between anterior and posterior root. know what ganglia are
nerve roots are nerves that emerge from the spinal cord as 2 distinct roots
posterior root: conatina axons of sensory neurons and convcery sensory input from the receptors
anterior root: composed of axons of motor neurons and convert motor information from the CNS to the effectors to produce a response
a ganglia is a cluster of neuronal cells bodies int the PNS
42
anterior median fissure vs posterior median fissure. describe the filum terminale
The anterior median fissure is a wide groove on the anterior (ventral) side. The posterior median sulcus is a narrow furrow on the posterior (dorsal) side.
filum terminale (FĪ-lum ter-mi-NAL-ē = terminal filament), an extension of the pia mater that extends inferiorly, fuses with the arachnoid mater and dura mater, and anchors the spinal cord to the coccyx.
43
label the spinal cord in vertebra
44
know these tissue
45
label spinal cord cross section
46
what ia nerve
a bundle of axons from multiple neurons and part of PNS
47
what are mixed nerves
he posterior roots contain axons of sensory neurons and convey sensory input from the
receptors to the CNS. The anterior roots are composed of axons of motor neurons and convey
motor information from the CNS to the effectors to produce a response. Anterior and posterior
roots join outside the spinal cord to form mixed nerves, nerves that have both sensory and
motor functions.
48
define reflexes
Reflexes are rapid, automatic sequences of actions that occur in response to a stimulus. The
purpose of most reflexes is to maintain homeostasis in the body
can be innate or learned (like catching a ball)
49
what is a reflex arc and what are the 5 componenets
all reflexes involve a reflex arc which is the route an impulse
takes to produce a reflex action. There are five basic components of a reflex arc: the sensory
receptor, a sensory neuron, an integrating center, a motor neuron, and the effector.
Information received by a sensory receptor is transmitted by a sensory neuron to an
integrating center (either the spinal cord (for spinal reflexes) or the brain (for cranial
reflexes)). From there, the information is processed by interneurons and transferred to a
motor neuron which then transmits the impulse to an effector (a muscle or a gland)
50
describe and autonomic / visceral reflex
A reflex that results in secretion by a gland or in the contraction of smooth or cardiac muscle
is called an autonomic or visceral reflex. Reflexes mediated through the autonomic
nervous system regulate body functions such as digestion, elimination, blood pressure,
salivation and sweating.
51
what is a somatic reflex
We will also be testing somatic reflexes, a type of reflex which results in the contraction of
skeletal muscles. More specifically, you will be testing different stretch reflexes, the
simplest form of somatic reflex. In a stretch reflex, the effector muscle is the same muscle
as the one that is being stimulated. Stretch reflexes are constantly activated in your body to
maintain posture. Other types of somatic reflexes include tendon reflexes, flexor reflexes and
cross-extensor reflexes
52
53
list 3 receptos and 3 effectors involved in reflex arc
receptors: baroreceptos, heat receptors, pain receptors
effectors:
glands, skeletal muscle, smooth muscle, cardiac muscle. ( anything that reacts)
54
what is the function of the brain
The function of the brain is to receive and integrate the vast majority of sensory stimuli and
coordinate appropriate responses. The brain is also the site of intelligence, emotions, complex
thinking, and the formation of memories.
55
what are the 4 major sections of the brain. describe them
The adult brain is composed of four major sections: the cerebrum, the diencephalon, the
cerebellum, and the brain stem. The brain stem is continuous with the spinal cord, the
diencephalon is superior to the brain stem and the cerebrum is superior to the diencephalon.
The cerebellum is posterior to the brain stem. The brain is enclosed by the cranial meninges
and is protected from physical damage by the bones of the cranium
56
The meninges of the brain are continuous with those of the spinal cord. What are thenames
of the three meninges?
dura mater (outermost), arachnoid mater and pia mater
57
describe the venous sinuses and the falx cerebri
The cranial dura mater has two layers that are fused together except where they enclose the
venous sinuses. The venous sinuses drain blood from the brain to the internal jugular veins.
The dura mater also has extensions that separate major brain structures. The falx cerebri is
an extension of the dura mater that separates the two cerebral hemispheres and attaches to
the crista galli of the ethmoid bone. Note that there is no epidural space between the dura
mater and the bones of the skull
58
describe the arachnoid mater in the brain
The arachnoid mater penetrates through the dura mater into the venous sinuses with
extensions of tissue called arachnoid granulations (villi). Cerebrospinal fluid is reabsorbed
into the blood through the arachnoid granulations
59
60
describe the cerebrum
The cerebrum is the most superior portion of the brain and is highly developed in humans and
other primates. It is divided into halves, the right and left cerebral hemispheres. Enclosed
in the cerebrum are the lateral ventricles, which we will discuss in detail later in this lab. Each
hemisphere of the brain may be divided into four basic areas, termed lobes.
61
describe the different lobes of the cerebrum
These lobes are named for the bones of the skull under which they are found: the frontal
lobe, the parietal lobes, the occipital lobe, and the temporal lobes.
62
the surface of the cerebrum has many convulutions. describe them
The surface of the cerebrum has many convolutions in the tissue; deep grooves are called
fissures and shallow grooves are called sulci (singular: sulcus). On either side of a sulcus
is a bulge of tissue called a gyrus (plural: gyri). A prominent sulcus called the central
cerebral sulcus forms a key landmark on the brain as it separates the frontal and parietal
lobes of the cerebrum. The gyrus anterior to the central sulcus is called the precentral gyrus
and the gyrus located posterior to the central sulcus is called the postcentral gyrus. The
right and left hemispheres are separated from each other by the longitudinal cerebral
fissure.
63
64
65
describe the cerebellum
The cerebellum is the second largest part of the brain and is found posterior to the brain stem.
The cerebellum is highly convoluted and contains nearly half of the neurons found in the brain.
As in the cerebrum, the cerebellum has superficial grey cortex and deep white matter. The
cerebellar white matter is known as the arbor vitae as its structure resembles a tree.
66
describe the brain stem
The brain stem consists of three major structures: the midbrain, the pons and the medulla
oblongata. The midbrain and pons are superior to the medulla oblongata and form an
important relay center in the brain. These structures transmit sensory and motor input from
the spinal cord to the cerebral hemispheres to be processed.
67
describe the medulla oblongata
The medulla oblongata is immediately superior to and merges with the spinal cord. Most of
the large motor tracts descending from the cerebrum cross over in the medulla so that skeletal
muscle fibers on the right side of the body are controlled by the left side of the brain.
68
know the weird alien thing
69
what is the diecephalon
Inferior to the cerebrum and superior to the brain stem is the diencephalon. This central
region of the brain contains many important structures that can only be seen in sagittal section
as they are enclosed by the cerebrum, the cerebellum, and the brain stem
70
describe the structures in the diecephalon
Inferior to the cerebrum and superior to the brain stem is the diencephalon. This central
region of the brain contains many important structures that can only be seen in sagittal section
as they are enclosed by the cerebrum, the cerebellum, and the brain stem.
Immediately inferior to the cerebrum is a white structure called the corpus callosum (part
of the cerebrum, which contains axons that connect the right and left cerebral hemispheres.
The thalamus forms the lateral walls of the diencephalon and encloses the third ventricle.
Centrally located in the thalamus is the interthalamic adhesion (intermediate mass), a
region of gray matter that connects the left and right thalamus regions. The
hypothalamus, the floor of the diencephalon, gives rise to the infundibular stalk, a
ventral down growth of tissue that attaches to the pituitary gland.
71
list the hormones secreted by the pituitary gland
Your pituitary gland makes:
growth hormone — which regulates growth
thyroid stimulating hormone (TSH) — which tells the thyroid gland to make hormones
prolactin — which controls breast milk production
adrenocorticotrophic hormone (ACTH) — which tells the adrenal glands to make hormones
follicle stimulating hormone (FSH) — which is involved in the reproductive system
luteinising hormone — which is also involved in the reproductive system
Your pituitary gland also stores and releases:
oxytocin — which is involved in childbirth and breastfeeding
vasopressin — which helps control the amount of salt and water in your body
72
describe the epithalamus
The epithalamus is the roof of the diencephalon, the tissue superior to the third ventricle.
Within the epithalamus is the pineal gland, a small posterior projection of endocrine tissue.
The pineal gland secretes melatonin
73
what are the functions of melatonin
Melatonin is an important player in the regulation of energy metabolism and glucose homeostasis
74
what are the ventricles of the brain, what is found there.
Within the brain are cavities called ventricles that are filled with cerebrospinal fluid (CSF).
The two lateral ventricles are enclosed in the cerebral hemispheres and are separated
anteriorly by a thin membrane called the septum pellucidum. The third ventricle is found
in the thalamus and the fourth ventricle is found between the brainstem and the cerebellum.
Within each of the ventricles are networks of blood capillaries called the choroid plexuses
that are lined by neuroglial cells that produce and circulate cerebrospinal fluid.
75
what type of neuroglial cell produces cerebrospinal flui
ependymal cells
76
where does cerebrospinal fluid flow through
Cerebrospinal fluid flows from the lateral ventricles to the third ventricle through channels
called interventricular foramina. From the third ventricle, the CSF flows through the
aqueduct of the midbrain (cerebral aqueduct) to the fourth ventricle. From the fourth
ventricle, CSF enters and circulates through the central canal of the spinal cord and the
subarachnoid space
77
what are 3 functions of cerebrospinal fluid
1. nutrient transport and waste removal
2.acts as a shock absorber
3. maintains chemical environment. (pH)
78
79
80
describe the blood circulation of the brain
Constant and consistent blood supply to the brain is critical for normal functioning because
the brain does not have the ability to store glucose. Oxygen and glucose must be brought to
the brain via the internal carotid and vertebral arteries. These arteries connect to the cerebral
arterial circle, also known as the Circle of Willis. This group of blood vessels creates
redundancies in the cerebral blood supply to ensure that if one side of this circle becomes
damaged, the other side can compensate and maintain adequate blood supply to brain tissue.
The cerebral arterial circle also equalizes blood pressure to the brain.
Venous blood circulates through the venous sinuses that are found between the two layers of
the dura mater and leaves the brain via the internal jugular veins
81
82
what is a choroid plexus and why are they important to the nervous system
The choroid plexus is a network of specialized cells and blood vessels located within the brain's ventricles, primarily responsible for producing cerebrospinal fluid (CSF). There are four choroid plexuses, one in each ventricle of the brain (two in the lateral ventricles, one in the third ventricle, and one in the fourth ventricle).
Key Functions of the Choroid Plexus:
CSF Production: The choroid plexus filters blood plasma and transforms it into CSF, which then circulates around the brain and spinal cord. This constant production and renewal of CSF are critical to maintaining the fluid's protective and homeostatic roles.
Barrier Function (Blood-CSF Barrier): The cells of the choroid plexus form a blood-CSF barrier that selectively allows certain substances to pass into the CSF while blocking others. This barrier helps control the chemical environment of the brain, ensuring that only essential nutrients and ions enter the CSF, while harmful substances and pathogens are kept out.
Waste Clearance and Detoxification: The choroid plexus not only produces CSF but also helps filter out waste products and toxins from the CSF. By regulating the exchange between blood and CSF, it assists in clearing out metabolic waste products that could otherwise accumulate in the brain.
83
describe the cranial nerves
There are twelve pairs of cranial nerves that conduct impulses to and from various parts of
the body including the olfactory epithelium, the retina of the eye, the muscles of the eyeball
and the face, the ear, the carotid arteries and structures in the throat, the heart and lungs,
the digestive tract, and the muscles of the neck.
84
what occurs to the optic nerve in the optic chiasm, anterior to the optic tract
form the optic chiasm (kī-AZM = a crossover, as in the letter X). Within the chiasm, axons from the medial half of each eye cross to the opposite side; axons from the lateral half remain on the same side.
85
what does the oflfactory bulbs and tracts do? are they sensory/ motor or mixed? what effect does it have on the body part
he olfactory epithelium occupies the superior part of the nasal cavity, covering the inferior surface of the cribriform plate and extending down along the superior nasal concha
special senses
conveys impulses relates to smell
86
what are some simple test to test cranial nerve function
convergence in pupillary constriction.
shining light in eyes to see if pupils react
87
describe sensory receptors
The central nervous system (CNS) is continually receiving, integrating and responding to input
from the senses. Sensory impulses originate from a variety of sensory receptors. Sensory
receptors are either specialized cells or the dendrites of a sensory neuron. They provide the
CNS with information about the body’s internal and external conditions.
Most receptors are sensitive to one particular stimulus and relatively insensitive to others.
The rods and cones of the retina, for example, are stimulated by light rays and not by smells
or sounds
88
describe the tiny receptors of the gernal senses and receptors for special senses
The tiny receptors of the general senses respond to stimuli such as chemicals, change in
temperature or mechanical deformation, and are distributed throughout the body. Receptors
for the special senses are housed in specialized sense organs. The special senses include
sight, taste, smell, hearing and equilibrium.
89
how are sensation consciously percieves
In order for a sensation to be consciously perceived, the action potential initiated by the
sensory receptor must be conducted to the CNS and must reach a region of the brain where
the stimulus is perceived and interpreted. Action potentials that reach the cerebral cortex are
consciously interpreted as sensations. An action potential that is interpreted at the level of
the spinal cord or brain stem (and therefore does not reach the cerebral cortex) causes a
reflex response to be initiated but conscious perception does not occur.
90
how are general senses divided
The general senses can be divided into the somatic senses and the visceral senses. The
somatic senses include tactile sensations, thermal sensations, pain sensations and
proprioception. The somatic sense receptors are located in the skin (cutaneous sensations)
or are embedded in muscles, tendons or joints.
91
where are the receptors of the visceral senses found
The receptors of the visceral senses are found in the internal organs and include stretch
receptors in the walls of hollow organs, chemical receptors in the epithelium of hollow organs,
and pressure receptors. As the visceral senses provide information about the conditions within
the internal organs, we will not be performing experiments to demonstrate them.
92
describe the receptors for somatic sensations
Receptors for somatic sensations may be bare dendrites, such as free nerve endings, or
encapsulated dendrites. The type of connective tissue capsule around an encapsulated nerve
ending enhances its sensitivity or specificity to a stimulus.
93
what are the 6 different receptors for tactile receptors
1. tactile corpuscles
2. hair root plexus
3. nonencapsulated sensory corpuscles
4.bulbous corpuscles
5. lamellar corpuscles
6. free nerve endings
94
describe tactile corpuscles
actile corpuscles (Meissner corpuscles) are found in the dermal papillae of highly
sensitive areas of hairless skin. They detect the onset of the sensation of touch and
detect low frequency vibration.
95
describe the hair root plexus
b)The hair root plexus consists of free nerve endings wrapped around hair follicles and
detects movements that disturb the hairs.
96
describe the nonencapsulated sensory corpuscles
) Nonencapsulated sensory corpuscles (Merkel discs or tactile discs) are free nerve
endings that associate with tactile epithelial (Merkel) cells in the stratum basale of highly
sensitive areas of hairless skin. They detect pressure and continuous touch, and are
numerous in the fingertips, hands and lips
97
describe bulbous corpuscles
ulbous corpuscles (Ruffini corpuscles) are encapsulated receptors deep in the dermis,
in ligaments and tendons, where they detect stretching and steady pressure.
98
describe lamellar corpuscles
Lamellar corpuscles (Pacinian corpuscles) are encapsulated dendrites located in the
dermis and subcutaneous regions. They detect high frequency vibrations and steady
pressure.
99
describe free nerve endings
Free nerve endings in the skin that are stimulated by certain chemicals result in the itch
sensation. Tickle is also thought to be the result of stimulation of a free nerveending.
100
101
know which corspuscle is which
102
which areas are most sensitive
back of neck and pingerstips, hands and lips as well
103
which nerve ending detect pain
nociceptors. found in all body tissues except the brain. stimulated by physical or chemical damage
104
what is proprioception. explain the sensation. which major parts of the brain receive input from these receptors
cerebellum, brain stem,
105
