Tercer Parcial Flashcards
The nervous system divides into…
Central and peripheral
Components of the central nervous system:
Brain and spinal cord
Components of the peripheral nervous system:
Nerves
Functions of the nervous system:
Regulate operations of the body, muscles and glands by sending impulses or signals
They are also called nerve cells and are excitable cells that make up the nervous system
Neurons
Name the three types of neurons
Sensory, inter and motor
Type of neurons activated by stimuli (light, touch)
Sensory neurons
Type of neurons that receive and send signals from and to neurons
Inter neurons
Type of neurons that control muscles and glands
Motor neurons
What are the three parts that all neurons have?
Cell body, dendrites and axon
Part of the neuron that contains the nucleus and organelles
Cell body
Part of the neuron that consists of branched cytoplasmic extensions that can pick up messages from other nerve cells
Dendrites
Part of the neuron that consists of a cytoplasmic extension that transmits electrical signals and releases chemical signals at its endings
Axon
Type of neuron that holds other neurons in place and produces myelin
Neuroglia or glial cells
Increases the speed at which signals travel along an axon
Myelin
Brief transversal of the electric gradient across the plasma membrane
Action potential
They carry messages between cells
Chemical signals
Region where a neuron’s axon terminal transmits signals to another cell
Chemical synapse
Name the 6 neurotransmitters
Acetylcholine, epinephrine, norepinephrine, dopamine, serotonin and endorphins
Neurotransmitter that induces skeletal muscle contraction, slows cardiac rate and affects memory
Acetylcholine
Neurotransmitters that speed heart rate, dilate pupils and airways and increase anxiety
Epinephrine and norepinephrine
Neurotransmitter that has roles in memory, learning and motor control
Dopamine
Neurotransmitter that elevates mood
Serotonin
Neurotransmitters that elevate mood, promote feelings of well being and decrease pain
Endorphins
What are the two divisions of the peripheral nervous system?
Somatic and autonomic
Division of peripheral nervous system that controls the skeletal muscles and voluntary moves
Somatic nervous system
Peripheral nervous system division that relays signals to smooth and cardiac muscle and glands. It controls involuntary moves
Autonomic nervous system
Which are the two divisions of the autonomic nervous system?
Parasympathetic and sympathetic
Division of the autonomic nervous system that activates when relaxed, release acetylcholine
Parasympathetic division
Division of the autonomic nervous system that activates when excited or in danger. Releases norepinephrine
Sympathetic division
Membranes that enclose and protect the brain and spinal cord in the central nervous system
Meninges
Protective mechanism that prevents unwanted substances from entering the cerebrospinal fluid
Blood brain barrier
There are two types of tissue in the brain and spinal cord, which are:
White (bundles of axons) and gray (cell bodies, dendrites and neuroglial cells)
Portion of the central nervous system that runs through the vertebral column and connects the peripheral nerves with the brain
Spinal cord
Is an automatic response to stimuli
Reflex
It has an average weight of 3 pounds (1,240 grams) and 100 billion interneurons
Brain
Is divided into right and left hemispheres by a fisure
Brain
Thick band of tissue that connects the two brain hemispheres
Corpus callosum
Outer layer of gray matter in each hemisphere that has functions in language and abstract thought
Cerebral cortex
Name the 4 lobes of the brain
Frontal, parietal, occipital and temporal
Brain lobe that controls motor skills, expressive language and reasoning
Frontal lobe
Brain lobe that processes tactile sensory information, such as pressure, touch and pain, and essential to the five senses
Parietal lobe
Brain lobe that has roles in visual stimuli and information
Occipital lobe
Brain lobe that has roles in interpreting sounds and language we hear. Involved in memory
Temporal
Its name means “under the thalamus” and is the center for homeostatic control. It regulates thirst, appetite, sex drive and body temperature. It is also an endocrine gland.
Hypothalamus
Hormone-producing glands and secretory cells of a vertebrate body
Endocrine system
Secrete hormones into the bloodstream
Endocrine glands
Types of hormones (4):
Steroids, amines, peptides and proteins
Hormones produced by the hypothalamus
ADH and oxytocin (secreted by the anterior lobe of the pituitary)
Hormones released by the anterior pituitary
Prolactin and growth hormone
Gland that secretes melatonin. This secretions decrease when retina detects light.
Pineal gland
Hormone secreted by the thyroid gland
Thyroid hormone
What does the thyroid regulates
Metabolic rate
Are the main regulators of calcium level in blood and release parathyroid hormone
Parathyroid glands
Are the glands located above each kidney and each of this glands has two regions called adrenal cortex and adrenal medulla
Adrenal glands
Hormone secreted by the adrenal glands
Cortisol
Primary reproductive organs:
Male’s testes and female’s ovaries
Hormones secreted by the gonads (reproductive organs):
Estrogen, testosterone and progesterone (in different proportions)
Period during which the body’s reproductive organs and structures mature and begin to function. Sex hormone production starts during this period.
Puberty
Hormones that regulate maturation of eggs and prepare the body for pregnancy
Estrogen and progesterone
Hormone that regulates sperm production and facial hair
Testosterone
It usually happens between the ages 10 and 14 for girls and ages 12 and 16 for boys. Causes physical changes.
Puberty
First sign of puberty in girls is:
Breast development
First sign of puberty in boys:
Testicles and penis get bigger
What marks sexual maturity in females?
The menarche or first menstruation
What marks sexual maturity in males?
The spermarche or first ejaculation
Duct that carries sperm away from an epididymis and to a short ejaculatory duct
Vas deferens
Has a rounded head (glans) at the of a narrower shaft
Penis
Complex mixture of sperm, proteins, nutrients, ions, and signaling molecules. Sperm account for less than 5% of its volume.
Semen
They contribute to semen formation:
Seminal vesicles, prostate gland and bulbourethral glands
Hollow, pear-shaped organ above the urinary bladder
Uterus
A thick layer of smooth muscle makes up most most of the uterine wall
** note **
The uterine lining (endometrium) consists of glandular epithelium connective tissue and blood vessels
** note **
Is the lowest part of the uterus and is connected to the vagina
Cervix
Muscular tube that extends from the cervix to the body’s surface. It functions as the female organ of intercourse and as birth canal
Vagina
Is the externally visible portion of the female reproductive system
Vulva
Outer folds of the vagina -> labia majora
Inner folds of the vagina -> labia minora
** note **
Is the tip of an erectile organ
Clitoris
Is a general term for an immature egg
Oocytes
A girl is born with 2 million primary oocytes in her ovaries
** note **
What marks the first day of the menstrual cycle?
The onset of menstruation
How many days does the menstrual cycle have?
28 days
Hormone that stimulates reabsorption of sodium and water
Aldosterone
Cycle-induced hormonal changes can cause sadness, irritability, anxiety or headaches. This symptoms are known as:
Premenstrual syndrome (PMS)
Contractions of smooth muscle in the uterine wall during menstruation
Menstrual cramps
When do menstrual cycles stop?
After the menopause at the age of 50
How pregnancy happens?
Sex or intercourse
Sexual climax
Orgasm
During orgasm, the vaginal wall and pelvis contract rhythmically in females. In males, contractions force the sperm into the urethra which are then ejaculated in the vagina
** notes **
How many sperms, approximately, an ejaculation puts into the vagina?
From 150 to 350 million
Where are eggs fertilized?
In the oviduct
Which is the most effective method to prevent pregnancy?
Abstinence
Types of methods to prevent pregnancy
Hormonal methods, intrauterine methods, sterilization, emergency contraception, barrier methods, among others
Method that consists on removing the penis from the vagina before ejaculation
Withdrawal
Method that consists on rinsing the vagina immediately after intercourse
Douche
Surgical method in females:
Tubal ligation (or cutting)
Surgical method in males:
Vasectomy
Sperm poison or killer
Spermicidal
Flexible, dome-shaped device that is positioned inside the vagina so it covers the cervix
Diaphragm
Are thin, tight-fitting sheaths worn over the penis during intercourse
Condoms
Device inserted into the uterus
Intrauterine device (IUD)
Small, flat adhesive patch applied to the skin that delivers the same mixture of hormones as an oral contraceptive and blocks ovulation
Patch
Delivers a large dose of synthetic progesterone that prevents ovulation and interferes with fertilization.
Morning-after pill