THE RAT

1. THE RAT VOCABULARY FOR ENTIRE UNIT ON THE RAT

2. VOCABULARY KEY… • RATTUS norvegicus – the white rat; the Norweigan Rat • ROSTRAL – towards the head • CAUDAL – towards the tail • CONTRALATERAL – on the opposite side • IPSILATERAL – on the same side • NARES – entrance from nasal cavity to nasal pharynx • VIBRISSAE – whiskers • PINNAE - ears • PREPUTIAL ORIFICE – anterior to scrotal sac • SCROTAL SAC - scrotum • TEATS - nipples • URETHRAL ORIFICE - caudal to mammilary papillae

3. VOCABULARY CONTINUED… • VAGINAL ORIFICE – large opening located inferior and posterior to the much smaller external urethral orifice. • CAUDAL VERTEBRAE – vertebrae closest to the tail (coccyx) • SUBCUTANEOUS FASCIA – white layer of connective tissue • CUTANEOUS TRUNCI – muscle below skin • PECTORALIS – chest muscles; adduction of arm from sternum to humerous • LATISSIMUS DORSI – shoulder muscles in the thoracic region – flex upper arm • FASCIA – connective tissue fibers, usually collagenous, sheets or bands below the skin - attach, stabilize, enclose, separate muscles and other organs • CUTANEOUS BLOOD VESSELS AND NERVES – blood vessels and nerves within the dermal layer, just below the epidermis

4. VOCABULARY CONTINUED… • ABDUCTION – away from ventral midline • ADDUCTION – toward ventral midline • EXTENSION – increase in the angle between two articulating bones – the opposite of flexion • PROTRACTION – moving limb cranially • RETRACTION – moving limb caudally • SUPINATION – rotation of the forearm so that the palm faces anteriorly • PRONATION – rotation of the forearm that makes the palm face posteriorly • MUSCLE FASCIA – connective tissue around muscles • ORIGIN – point of attachment of a muscle; it is the end that is not easily moveable

5. VOCABULARY CONTINUED… • INSERTION – point of attachment of a muscle; it is the end that is easily moveable • BELLY – the bulge of the muscle • SPINOTRAPEZIUS - originates along the middorsal line at the thoracic spines & the lumbodorsal fascia, & inserts on the spine of the scapula; it is superficial to the cranial border of the latissimusdorsi. It inserts on the humerus & retracts & flexes the brachium. • THORACOLUMBAR FASCIA - layer of deep fascia extends from the sacrum to the neck and binds the erector spinae muscle to the postero-lateral surfaces of the vertebrae. It is often referred to as lumbodorsal fascia. • *Posterior layer is the strongest and passes from the lumbar spines, superficial to the erector spinae, to fuse with the middle layer lateral to that muscle. • *Middle layer separates the erector spinae from the quadratuslumborum. *Anterior "quadratus" layer is thin but strong and covers the anterior aspect of the quadratuslumborum. Superiorly it is thickened to form the lateral lumbocostal arch which gives attachment to the diaphragm. • *Do not need to know these layers for the vocab quiz.

6. VOCABULARY CONTINUED… • SPINODELTOIDEUS – The spinodeltoideus comes from the spine of the scapula and inserts on the humerus. Both muscles assist in abducting and rotating the humerus. • ACROMIOTRAPEZIUS - The acromiotrapezius is a thin muscle extending from the occipital bone to the metacromion process of the scapula and is the middle of the three trapezius muscles. • TRICEPS BRACHI - Extends forearm/antibrachium; originates at the greater tuberosity of the humerus and attaches at the olecranon of the ulna. • BICEPS BRACHI - The job of your biceps muscle is to bend your elbow, and pull your forearm towards your upper arm. • ANTAGONIST - Counteracting or opposing.

7. VOCABULARY CONTINUED… • GLUTEUS MAXIMUS – large, triangular muscle; originates on ilium and inserts on femur. • FASCIA LATA – tough, white tissue that wraps the knee and lateral portion of the tibia. • BICEPS FEMORIS – abducts the femur, flexes the shank; broad band of muscle that originates on a bump of the ischium. • TUBEROSITY – processes formed where tendons or ligaments attach; a smaller, rough projection (page 188 in text). • QUADRICEPS – extends, rotates thigh (ischium to femur) • GASTROCNEMIUS – runs along the back of the tibia • SEMITENDINOSUS – originates from last few sacral vertebrae, extends ventrally and inserts on medial side of tibia.

8. VOCABULARY CONTINUED… • STERNOMASTOIDEUS – this originates at the cranial border of the manubrium & inserts at the mastoid; turns head to side or draws back of head down • EXTERNAL OBLIQUE – Muscle that inserts on the linea alba & border of the pubis & its action is to constrict the abdominal region. • LINEA ALBA – line between the external oblique muscles on belly side of the rat • INTERNAL OBLIQUE - Muscle that inserts on the linea alba & its action is to compress the abdominal region. • INTERCOSTAL – ribs, raise and expand thorax • GRACILIS – a broad, thin band of muscle on the thigh • APONEUROSIS – thick, flat band of connective tissue; becomes a tendon

9. VOCABULARY CONTINUED… • SARTORIUS – the longest muscle in the body; anterior superior spine of the iliac bone; insertion - Medial surface of the tibia; cruralfascia. • SEMIMEMBRANOUS – partly membranous; (membrane = thin, pliable layer of tissue covering surfaces, separating or connecting regions, structures or organs) • INTERNAL RESPIRATION – oxidation-reduction reactions that occur in cells • EXTERNAL RESPIRATION – mechanism whereby animals obtain oxygen and release carbon dioxide • PHARYNX – common passageway for both respiration and digestion • LARYNX - is an organ in the neck that plays a crucial role in speech and breathing; it is a valve separating the trachea from the upper aero digestive tract - primarily thought of as an organ of communication, a.k.a. voice box; important regulator of respiration & necessary for an effective cough; prevents aspiration during swallowing.

10. VOCABULARY CONTINUED… • EPIGLOTTIS - the flap of cartilage lying behind the tongue & in front of the entrance to the larynx (voice box). At rest, it is upright & allows air to pass through the larynx and into the rest of the respiratory system. During swallowing, it folds back to cover the entrance to the larynx, preventing food and drink from entering the windpipe. • TRACHEA - Your trachea is the tube that connects your mouth and nose to your lungs. You can also call it the windpipe; cartilaginous-ringed tube where air passes to the lungs from the mouth. • BRONCHI – paired tubes which are divisions of the trachea • ESCHERICHIA coli – bacteria of the large intestine that help break down food.

11. VOCABULARY CONTINUED… • PALATE – roof of the mouth • DUODENUM – first region of the small intestine • ILEUM - the final section of the small intestine. • CAECUM – curled blind sac coming off the colon or the small intestine; the first portion of the large bowel, situated in the lower right quadrant of the abdomen. The caecum receives fecal material from the small bowel (ileum) which opens into it. The appendix is attached to the caecum. • COLON – the large intestine • RECTUM - The rectumis like a storage-holder for this waste. Muscles in the rectum move the waste, called stool, out of the body through the anus. • URETHRA – carries semen and urine in male

12. VOCABULARY CONTINUED… • TUNICA VAGINALIS - (tunica vaginalispropria testis) is the serous covering of the testis. It is a pouch of serous membrane, derived from the saccusvaginalis of the peritoneum, which in the fetus preceded the descent of the testis from the abdomen into the scrotum • TUNICA ALBUGINEA - whitish membrane within the penis that surrounds the spongy chambers (corpora cavernosa) in the penis and which helps to trap the blood in the corpora cavernosa, thereby sustaining erection of the penis. • EPIDIDYMIS – collects sperm from the testes; a structure attached to the rear of the testis filled with a long twisting hollow tube. Sperm travel through the entire tubular system from the Head at the top, through the body in the middle and are temporarily held in the tail at the end. Responsible for sperm maturation, storage, transport up vas deferens, nutrition and concentration.

13. VOCABULARY CONTINUED… • CAPUT EPIDIDYMUS - (cap.e.), head of the epididymis, is attached to the top of the testicle and is directly connected to the seminiferous tubules of the testes.   • CAUDAL EPIDIDYMUS – sperm storage; the tail of the epididymis is attached to the bottom of the testicle and is easily palpated.   DUCTUS DEFERENS – carries sperm from epididymis to urethra • PROSTATE – heart shaped gland in male just caudal to the bladder • SEMINAL VESICLES – secretes seminal fluid into the urethra • PREPUTIAL GLANDS – paired glands near the tip of the penis • OVIDUCT – a convoluted tube of the female reproductive system just below the ovary

14. VOCABULARY CONTINUED… • UTERINE HORNS - extend toward the kidneys. This duplex uterus is common in some animals and will accommodate multiple embryos (a litter). In contrast, a simple uterus, like the kind found in humans has a single chamber for the development of a single embryo. • VAGINA – canal from the uterus to the outside • CLITORIS AND GLANDS – homologue to the male penis • PRECAVA – collects blood from the head and forelimbs • POSTCAVA – main drainage vessel for everything except the head and forelimbs • HEPATIC – refers to the liver

15. VOCABULARY CONTINUED… • FEMORAL – drains the hindlimbs • PULMONARY – refers to the lungs • COMMON CAROTID – supplies the head with blood • SUBCLAVIAN – supplies blood to the region of the forearms • INNOMINATE – a short artery that divides to form the right carotid and subclavian • COELIAC - the most anterior (first branch in the abdominal cavity after the diaphragm); i.e., the coeliac artery which supplies the spleen, pancreas and stomach • RENAL – refers to the kidney