last bio lecture

A layer of phospholipids is impervious to ions. How, then, do ions cross the phospholipid membrane of a neuron to transmit a nerve impulse?

They pass through the proteins embedded in the plasma membrane.

Each neuron has a long arm called the axon, which sends signal to other neurons dendrites

True

T cells direct humoral immunity while B cells govern cell- mediated immunity reactions

True

The two hormones produced by the thyroid are thyroxine and tridothyronie

True

A human embryo may have the chromosomes XX or XY which of these is a female?

XX

what is able to pass across the placenta between the embryo/fetus during pregnancy?

all of these

As the wave of the electrical polar reversal and correction travels down the neuron what keeps the nerve impulse traveling in the right direction and keeps it from traveling backward?

as the nerve impulse travels down a neuron it actually destroys the neuron, which must be quickly repaired by the gilia

As the fertilized egg continues to develop in humans a neural tube is formed this neural tube will continue to develop and become the ?

brain and spinal column

The is the most ancient part of the brain. It coordinates motor control signals sent from the brain to the body. It controls several important functions of the body including alertness, arousal, breathing, blood pressure, digestion, heart rate, swallowing, walking, and sensory and motor information integration.

brainstem

A human embryo develops into a male due to a hormone secreted by ?

by the father

which part of the brain controls balance and aids in coordinating movement and learning new motor tasks?

cerebellum

in a process called an army of plasma cells and memory cells are produced from properly stimulated B cells

clonal selection

A phagocyte is a cell that

engulfs other cells and debris

white blood cells are produced

from bone marrow stem cells

what is the first stage in human development in which there are three germ layers?

gastrula

the transmission of a nerve impulse results from a reversal of electrical charge that moves down the neuron.Following this wave of change ifnelectrical charge is a wave that returns things to the resting stage. What ions are moved in and out of the nerve cell] to accomplish these things?

guess

an immunodeficiency means that

immune sytem lacks one or more essential components

The phospholipid membrane that is the cell membrane of the neuron is slightly electrically negative. one side is more negative than the other when the neuron is at rest, not transmitting a nerve impulse. which side is more negative at rest?

inner surface

When activated triggers a chain reaction that punctures bacterial cell membranes

interleukin.

A primary antigen presenting cell a cell that presents an antigen that activates a helper T cell, is a

macrophages

if a child is born on December 25 what is the most likely date of its conception?

march 25

Which of the following structures is part of the brainstem.

medulla oblongata, midbrain, and pons.

which of these methods of reproduction is an example of sexual reproduction?

none

When someone has been knocked unconscious or falls and hits his head and then "sees stars" an injury to what part of his brain accounted for "seeing stars"

occipital

What reproductive and developmental structures do human have that birds do not have ?

ovaries

Many land animals have adapted to reproducing on land by keeping the developing embryo on an "artificial sea" called amnion. Which of these methods of land reproduction keeps the embryo in amniotic fluid within an egg?

ovoviparity

one hormone functions both in causing uterine contractions during labor and in the production of milk what is the hormone?

oxytocin

The endocrine gland that produce hormones that help regulate blood and calcium is the

parathyroid

Special cells produced by the immune system that are progeny of properly stimulated B cells and are antibody- producing factories are

plasma cells

Human sperm are the motile only in an alkaline environment. The vagina of a woman in her childbearing years is usually acidic? How are sperm able to function in such an environment?

semen contains an alkali to reverse the vaginal acidity

Human sperm need a lot of energy to swim fast and hard. Where does that energy come from?

semen contains fructose

which can be a target of autoimmune disease but is not considered to be a major part of the immune system itself?

spleen

which of the following is NOT an endocrine organ?

spleen

your text book speaks of epinephrine and adrenaline and norepinephrine being the neurotransmitters associated with the nervous sytem

sympathetic

Physical and chemical barriers that form the first line of innate defense include

All answers are correct.

in order to maintain the resting potential of mV, the sodium potassium pump moves three ions out of the cell and two ions into the cell.

Answer 34: The sodium potassium pump functions to maintain ionic balance in cell. It involves : Exit of 3 sodium ions from cell interior, and entry of 2 potassium ions into cell from outside. Hence correct choice should be: D. Sodium ions out of the cell and potassium ions into the cell. Answer 35: After depolarization phase, sodium gates close and potassium gates open. Answer 35: (B) Answer 36: (D) thick myelinated neurons Answer 37: ( A) post synaptic dendritic membrane

are foreign molecules that stimulate the production of

Antigens, antibodies

explain how a neuron can send a signal across the synaptic gap

Each neuron picks up signals at its dendrites, passes the signals down the aon, into the aon terminals, and into the synapses. The synapse then drops neurotransmitters into the synaptic cleft between the first neuron's synapse and the next neuronsdendrites.

There is a kind of cell in the nervous system that performs many functions such as forming the blood-brain barrier, producing cerebrospinal fluid, producing the myelin sheath of some nerve cells, and generally sustaining and protecting the neuron. this kind of cell is called

Ependymal cells produce cerebrospinal fluid that cushions the neurons

innate immune responses involve antibodies

False

The placenta is part of the body.

Fetus's

The "master" cells of the immune system that initiate and coordinate the adaptive immune response are

Helper T cells

B cells and T cells are

Lymphocytes

A person who is an organ transplant recipent must take immune suppressant drugs for the rest of his / her life because the donated organ will have a different

Major histocompatibility complex

Which of these forms of reproduction requires an egg?

None of these

The hypothalamus is both part of the brain/central nervous system and part of the endocrine system

true

which of these means of reproduction uses a placenta?

viviparity

which of the following is a function of the helper T cells?

Secretion of cytokines

Many animals that live in the water cast their sperm and eggs into the waters by the thousands, where they join and produce offspring. What are the implications, advantages or disadvantages of such way of reproducing ?

wrong answer is it is not often found in animals that swim around

Which of these statements about menopause and post-menopause is False?

There are still eggs and potential follicles on the ovaries