BIO ll Exam 5

The central nervous system is composed of?

the brain housed in the skull and spinal cord which is house in the vertebral column.

The peripheral nervous system is composed of?

Consists of all nerves and ganglia that lie outside the CNS.

 

What are somatic and autonomic divisions of?

PNS

The somatic system controls?

sensory and motor functions that control skeletal muscle

The autonomic system controls?

controls smooth muscle, cardiac muscle, and glands

The sympathetic and parasympathetic are divisions of what?

Autonomic system

What are the functions of the human nervous system?

Sensory input, integration, generation of motor output, and detection of stimuli

What are the 2 major types of cells in neural tissue?

Neurons: cells that are specialized to produce and conduct electrochemical impulses.

Neuroglia: supports or protects the neurons.

What are dendrites and axons?

Dendrites: cytoplasmic extensions of a neuron that carry impulses toward the cell body

Axon: conducts nerve impulses away along the long cellular extension of the neuron; covered by myelin sheath (white, insulating layer that protects)

Motor (efferent) neurons:

accept nerve impulses from the CNS, transmit them to muscles or glands; multipolar

Sensory (afferent) neurons:

accept impulses from sensory receptors, transmit them to the CNS; Unipolar

Interneurons:

convey nerve impulses between various parts of the CNS, multipolar. form complex pathways in the brain. lead to higher mental functions thinking, memory, and language

The connection space between the dendrite of one cell and the axon of another cell is called a(n)?

Synapse

What are neurotransmitters?

molecules that cross synaptic cleft and either excite or inhibit postsynaptic neuron

Spinal cord and brain are wrapped in three protective layers of membranes called?

Meninges and spaces between meninges are filled w/ cerebrospinal fluid

The primary functions of the spinal cord are?

Center for many reflex actions. Automatic responses to external stimuli. Facilitate communication between the brain and spinal nerves

spinal cord contains white matter (myelinated)

cerebrum contains gray matter (unmyelinated)

What occurs in the cerebrum?

largest portion of the brain in humans. part of brain where correlation, association, and learning occur. Integrates sensory input from the eyes, ears, muscles, and joins with motor information from the cerebral cortex

What hemisphere of the brain is associated with analytical reasoning?

Left hemisphere

Associated with artistic and musical ability?

Right hemisphere

What is the function of the cerebellum?

integrates sensory input from the eyes, ears, muscles, and joins with motor information from the cerebral cortex. sends motor impulses out the brain stem to the skeletal muscles.

What does the hypothalamus do?

forms the floor of the third ventricle. integrating center that maintains homeostasis- integrates visceral activities, body temperature and heartbeat. controls the pituitary gland.

Releasing and inhibiting hormones; regulate the anterior pituitary. Regulates appetite, maintains water balance in the body, controls body temperature and sleep.

Thalamus:

receives all sensory input except smell and integrates sensory information and sends it to the cerebrum.

Brainstem:

Midbrain: acts as a relay station for tracts passing between the cerebrum and the spinal cord or cerebellum

Pons: contains axons that form a bridge between the cerebellum and the rest of the central nervous system

Medulla Oblongata: contains reflex centers for heartbeat and respiration, as well as - vomiting, coughing, sneezing, hiccupping, and swallowing

What structure in the mammalian brain is enlarged and is responsible for higher mental processes?

Forebrain

What does the limbic system do?

integrates higher mental functions and primitive emotions (provides reasoning to keep us from acting out strong feelings). includes hippocampus and amygdala

What is a reflex action?

automatic, involuntary response to a stimulus.

Chemoreceptors:

sensory receptors responsible for taste and smell

Photoreceptors:

sensory receptors responsible for responding to light (vision)

Mechanoreceptors:

sensory receptors stimulated by mechanical forces, such as pressure (hearing)

Where are the photoreceptors of the eye found?

Retina which contains rod cells (night vision) and cone cells (bright light; allow color). Contains the fovea centralis responsible for acute vision; densely packed cone cells where light is focused.

Sclera:

opaque outer layer. Fibrous layer covering most of the eye. In front of the eye, the sclera becomes the transparent cornea.

Conjunctiva:

covers surface of the sclera and keeps the eyes moist.

Choroid:

Thin middle layer. Contains blood vessels. In front of the eye, the choroid thickens to form the ciliary body and the iris.

Iris:

regulates the size of the pupil (opening for light).

Aqueous humor:

the fluid in the eye between the cornea and the lens.

Lens:

helps form images.

Ciliary muscle:

controls the shape of the lens to maintain a clear image of focus at various distances

Correct order in which a light ray reaches the retina:

Cornea – aqueous humor – pupil – lens – vitreous humor – retina

Myopic:

Nearsighted; Elongated eyeball; Wear concave lenses

Hyperopic:

Farsighted; Shortened eyeball; Wear convex lenses

What are semi-circular canals?

the part of the inner ear that recognizes rotational equilibrium and movement

Outer ear:

Pinna and auditory canal. Opening of auditory canal is lined with fine hairs and glands.

Middle ear:

begins at tympanic membrane (ear drum) and ends at oval and round windows.

The ossicles (three small bones) are found between the tympanic membrane and the windows: Malleus (hammer), incus (anvil), and stapes (stirrup).

Auditory (eustachian) tube:

extends from the middle ear to the nasopharynx. Permits equalization of air pressure.

Inner ear:

semicircular canals, vestibule (concerned with equilibrium), and cochlea (concerned with hearing)

Path of sound through the ear:

Auditory canal – tympanic membrane – malleus – incus – stapes – oval window – cochlear nerve

Functions of skeletal system:

Support of the body, protection of vital internal organs, sites for muscle attachment, storage reservoir for calcium and phosphorus ions, and production of blood cells (in adults).

What do osteoblasts and osteoclasts do?

Osteoblasts: bone-forming cells; Synthesize new matrix

Osteoclasts: bone-absorbing cells; Break down bone, remove worn cells, release calcium in the blood; Contribute to blood calcium homeostasis

Osteocytes: mature bone cells

Describe compact bone.

Unit of structure is called osteon (Haversian systems). Osteocytes lie in lacunae (tiny chambers in concentric circles around a central canal). Concentric lacunae are arranged around a central canal containing blood vessels and nerves. Lacunae are separated by a matrix of collagen fibers and mineral deposits

Describe spongy bone:

Numerous bars and plates separated by irregular spaces. Spaces are filled with red bone marrow, which produces blood cells (white blood cells). Yellow bone marrow stores fat and bone and aids in storage of fats.

What bones are in the axial skeleton?

Lies in the midline of the body and consists of the skull, vertebral column (backbone), thoracic cage (sternum, ribs, costal cartilage), sacrum, and coccyx

Appendicular skeleton:

bones within the pectoral (shoulder) and pelvic (hip bones) girdles; the attached limbs

What are the common types of joints in the human body?

Fibrous Joints: immovable; between cranial bones.

Cartilaginous Joints: slightly movable; between vertebrae.

Synovial Joints: freely movable; bones are separated by a cavity; ligaments (bone to bone)

Examples of synovial joints:

Hinge joints: permit movement in one direction. Ex. finger, knee and elbow joints.

Pivot joint: permits rotational movement. Ex. joint between the first two cervical vertebrae (neck).

Ball-and-socket joint: allow movement in all planes as well as rotational movement. Ex. ball of femur fits into a socket on the hip bone

Immovable joint: sutures of the skull

Two types of muscle that is striated?

Cardiac and skeletal muscle

Type of muscle that contracts and cause bones to move?

Skeletal muscles

What attaches muscle to bone?

tendons

Myofibrils have thin filaments made of:

actin

Myofibrils have thick filaments of:

myosin

What provides energy for muscle contraction?

ATP

What is acetylcholine?

Neurotransmitter that is released from the motor neuron at the neuromuscular junction

Compare exocrine and endocrine glands. Give examples.

Exocrine glands: secrete products into ducts, which subsequently take them to lumens of other organs or outside the body. (sweat, tears, milk)

Endocrine glands: secrete products directly into the bloodstream, which delivers them throughout the body.

How does the release of ADH by the pituitary an example of negative feedback?

Through the reabsorption of water by kidneys; Effect of the hormone acts to shut down the release of the hormone

The positive feedback: produces oxytocin; Stimulus continues to bring about an effect that ever increases in intensity.

What are pheromones?

Chemical signals that influence the behavior of other individuals

What type of hormones act more slowly and maintain their effects longer?

Steroid hormones act more slowly than peptides, but action lasts longer

What would cause uncommonly large hands and feed and why?

Acromegaly; caused by overproduction of growth hormone (GH) in adults

What will prevent goiter?

Ensuring adequate iodine intake

Where is the pineal gland located and what does it produce?

Located in the brain and produces melatonin; involved in circadian rhythms (sleep-wake cycle)

What are prostaglandins?

Act locally, affecting neighboring cells; NOT DISTRIBUTED IN BLOOD

What is the job of the placenta?

Allows exchange of molecules between maternal and fetal blood; viviparous

Where are sperm produced?

Produced by the testes.

Where does sperm go to mature and be stored?

Matures in the Epididymis

What is the main sex hormone in male humans?

Testosterone

In a vasectomy, what is removed?

Removes portion of the vas deferens (surgical form of birth control).

In the human male, the tube used to carry both sperm and urine is the?

Urethra

When an egg erupts from a follicle, the chamber that remains and secretes hormones is the

corpus luteum.

Fertilization of the egg takes place where?

Fallopian (uterine) tube

The uterine lining sloughs off at what point in the female cycle?

During menstruation

The hormone produced by cells around the embryo that maintains the corpus luteum and pregnancy is

HCG

Which STDs are bacterial? Viral?

Bacterial: Chlamydia, gonorrhea, syphilis

Viral: AIDS, genital herpes, genital warts, and hepatitis A and B

What are the stages of cellular development in animals?

Cleavage (cell division without growth) → morula → blastula → gastrula

What is the first body system to develop in the human fetus?

Nervous system

Programmed cell death is called

apoptosis