Which of these is most vulnerable to irreversible damage caused by a very loud noise?
cochlear hair cells
When you spin while sitting in a swivel chair with your eyes closed, you can sense this movement by means of your
When you travel in an elevator, the ___ senses when the elevator is moving.
inner hair cells of the basilar membrane
The crista ampullaris is associated with
dynamic equilibrium related to angular acceleration.
Nerve fibers from all regions of the retina converge on the ___ and exit the eye by way of the optic nerve
___ are responsible for photopic (day) vision as well as trichromatic (color) vision.
___ are the only retinal cells that produce action potentials
The first-order neurons in the visual pathway are
the ganglion cells
Half of the fibers of each optic nerve decussate at the ___.
release their secretions directly into the blood.
The nervous system reacts to stimuli _____ compared to the endocrine system, adapts _____ compared to the endocrine system, and has _____ effects compared to the endocrine system.
quickly; quickly; specific
__ are secreted by one cell into the tissue fluid, diffuse to nearby cells in the same tissue, and stimulate their
What makes a cell responsive to a particular hormone?
the presence of a receptor for that particular hormone
The neurohypophysis (posterior pituitary) secretes
Thyrotropin-releasing hormone targets the
The hypophyseal portal system connects
the anterior pituitary (adenohypophysis) with the hypothalamus
___ has more target cells in the body than any of the others.
Growth hormone (GH)
Target organs most often regulate the pituitary gland via
negative feedback inhibition.
The infundibulum is
a portal system between the hypothalamus and the pituitary gland.
___ secretion is controlled by neuroendocrine reflexes, whereas ___ secretion is controlled by negative feedback mechanisms.
Oxytocin (OT); antidiuretic hormone (ADH)
Negative feedback inhibition occurs when
thyroid hormone (TH) targets the anterior pituitary
The ___ secretes a hormone that increases the body's metabolic rate, promotes alertness , quickens reflexes, and stimulates the fetal nervous system
The ___ secrete(s) a hormone as a response to hypocalcemia
The ___ secrete(s) ___, which promotes Na+ and water retention.
adrenal cortex; aldosterone
The zona fasciculata in the adrenal gland secretes
Many hours after a meal, alpha ( ) cells in the pancreatic islets (islets of Langerhans) secrete
glucagon, which raises blood glucose
T4 and T3 are _____ hormones that are mainly transported _____ in the blood.
monoamine; bound to thyroxine-binding globulin (TBG)
___ enters a target cell's nucleus and acts directly on the genes
This is the last step in the sequence of events happening when cyclic AMP acts as a second messenger.
enzymes are activated or deactivated by the action of protein kinases
Neither follicle stimulating (FSH) hormone nor testosterone alone can stimulate significant sperm production, whereas when they act together, the testes produce some 300,000 sperm per minute. This exemplifies
they synergistic effect
The initial response to stress is called ____ and is mediated mainly by ___.
the alarm reaction; norepinephrine and epinephrine
The buffy coat does not contain
_____________ is the most abundant protein in plasma.
Serum is essentially identical to plasma except for the absence of __________.
Erythrocytes transport oxygen and
transport some carbon dioxide.
Most oxygen is transported bound to
heme groups in hemoglobin.
The ABO blood group is determined by _____________ in the plasma membrane of RBCs.
Type A blood can safely donate RBCs to _____________ and can receive RBCs of type ___________.
Type AB blood has ____________ RBC antigen(s).
A and B
The universal donor of RBCs, but not necessarily plasma, is
The main reason why an individual AB, Rh-negative cannot donate blood to an individual A, Rh-positive is because
anti-B antibodies in the recipient will agglutinate RBCs of the donor
A woman's first pregnancy is normal but her second pregnancy results in hemolytic disease of the newborn (HDN), or erythroblastosis fetalis. The second child needed a transfusion to completely replace the agglutinating blood. The mother is most likely type _____ and both children are most likely _____.
A, Rh-negative; B, Rh-positive
These are the least abundant formed elements
These are the most abundant agranulocytes.
The differential count of ______________ typically increases in response to bacterial infections
___________ aid in the body's defense processes by secreting histamine (vasodilator) and heparin
The cessation of bleeding is specifically called
______________ belong to the pulmonary circuit
Pulmonary arteries and pulmonary veins
_____________ is the most superficial layer enclosing the heart.
Pericardial fluid is found between
the parietal and visceral membranes
The ________________ performs the work of the heart
The tricuspid valve regulates the opening between
the right atrium and right ventricle.
Oxygen-poor blood passes through
the right AV (tricuspid) valve only.
Opening and closing of the heart valves is caused by
Cardiac muscle shares this feature with skeletal muscle.
cardiac muscle fibers have striations
The ________________ is the pacemaker that initiates each heart beat.
sinoatrial (SA) node
This is the correct path of an electrical excitation from the pacemaker to a cardiocyte in the left ventricle (LV).